I have been trying to figure out whether the TextUML notation for action semantics can be dealt with properly by tools such as Xtext and EMFText (class models and state machines should be fine). For example, given this structural model fragment:

class Advertisement
    attribute summary : String;
    attribute description : String;
    attribute keywords : Keyword[*];
    attribute category : Category;
    operation addKeyword(keywordName : String);
    static operation findByCategoryName(catName : String) : Advertisement[*];
end;

association AdvertisementKeyword
    role Advertisement.keywords;
    role advertisement : Advertisement;
end;

class Keyword specializes Object
    attribute name : String;
end;

class Category specializes Object
    attribute name : String;
    attribute description : String;
end;

association AdvertisementCategory
    role Advertisement.category;
    role ad : Advertisement[*];
end;

Notice the Advertisement class declares two operations. Their behaviour in TextUML could be written as:

    operation Advertisement.addKeyword;
    begin
        var newKeyword : Keyword;
        newKeyword := new Keyword;
        newKeyword.name := keywordName;
        link AdvertisementKeyword(keywords := newKeyword, advertisement := self);
    end;

    operation Advertisement.findByCategoryName;
    begin
        return Advertisement extent.select(
            (a : Advertisement) : Boolean {
                return a->AdvertisementCategory->category.name = catName;
            }
        );
    end;

Note that TextUML allows the behavior to be specified inline when declaring an operation in a class, or in separate, as above (that explains the lack of parameters, modifiers etc).

In the resulting UML model, the behaviour of Advertisement.addKeyword would roughly map to this (using a textual pseudo-notation for UML activities that is hopefully more readable than raw XMI):

activity(name: "addKeyword") {
    structuredActivityNode {
        variable(name: "newKeyword", type: #String)
        writeVariable(variable: #newKeyword, value: createObject(class: #Keyword))
        writeAttribute(
            attribute: #Keyword.name,
            target: readVariable(variable: #newKeyword),
            value: readVariable(variable: #keywordName)
        )
        createLink(
            association: #AdvertisementKeyword,
            end1: #AdvertisementKeyword.keyword,
            end1Value: readVariable(variable: #newKeyword),
            end2: #AdvertisementKeyword.advertisement,
            end2Value: readSelf()
        )
    }
}

and the behaviour Advertisement.findByCategoryName would map to this:

activity(name: "findByCategoryName") {
    structuredActivityNode {
        // implicit variable for return value
        variable(name: "@result", type: #Advertisement, upperBound: *)
        // implicit variable for parameter value
        variable(name: "catName", type: #String)
        writeVariable(
            variable: #@result,
            value: callOperation(
                operation: #Advertisement.select,
                target: readExtent(class: #Advertisement),
                filter: metaValue(#@findByCategoryName_closure1)
            )
        )
    }
}

// a closure is an activity that has a reference to a context activity
closure(name: "@findByCategoryName_closure1") {
        // implicit variable for return value
        variable(name: "@result", type: #Boolean)
        // implicit variable for parameter value
        variable(name: "a", type: #Advertisement)
        writeVariable(
            variable: #@result,
            value: callOperation(
                operation: #Object.equals,
                // variables from the context activity are available here
                target: readVariable(variable: #catName)
                args: readAttribute(attribute: #Category.name, target: readLink(
                    association: #AdvertisementCategory,
                    fedEnd: #Advertisement.ad,
                    fedEndValue: readVariable(variable: #a),
                    readEnd: #Advertisement.category
                ))
            )
        )
}

Note that UML does not have closures, this is an extension to the UML metamodel which I wrote about here before.

Some background on the metaclasses involved: ReadVariableAction, CreateObjectAction, CreateLinkAction, ReadExtentAction etc are all action metaclasses. Actions are the building blocks for modeling activity behaviour in UML.

The million dollar question is: can Xtext and EMFText handle more complex textual notations like this? Is this out of the happy path? Has anyone done something similar? I am under the impression I could use Xtext or EMFText better if I used them based on a intermediate metamodel for behavior that would be closer to the concrete syntax (to get all the IDE bells and whistles for free) and then transformed that to UML in a separate step.

If you have the answers for any of these questions (or even if you have comments and questions of your own), please chime in.

Last Wednesday I attended the Eclipse Modeling Day in Toronto. Coming all the way from Victoria, I must have been the participant that came from farthest. Except, of course, those folks from SAP AG and Itemis that were presenting. But I was really glad to be there. I finally had the chance to chat and discuss about Eclipse and Modeling face to face with people like Simon Kaegi (server-side OSGi), Kenn Hussey (MDT UML2), Eike Stepper (CDO), Ed Merks and (fellow Brazilian) Marcelo Paternostro (EMF), Lynn Gayowski and Ian Skerret (Eclipse Foundation). It’s weird: I have been part of the Eclipse Modeling community since 2006 (and the larger Eclipse community since 2002), but had never actually met any of those folks before. Also amusing was that even though I worked for IBM Ottawa for quite a few years, my first time at the Toronto Lab was many years later as an ex-IBMer living on the West Coast.

The presentations I attended were in general very good. I had seen Ed Merks’ opening presentation on the web before, but this time I could ask questions. I got a better understanding of Xtext (great presentation!), CDO, and the Query, Validation and Transaction frameworks, some technologies I am considering adopting in the near future. I had a first time contact with the Papyrus 2.0 vision, which might provide an opportunity for increasing adoption of the TextUML notation by integrating the TextUML Toolkit into a larger modeling environment. And I liked the idea of a discussion panel at the end.

I had to catch a flight back home that same night, so I could not attend the Eclipse RT Day on the following day nor could I see any of the demos at the DemoCamp. Speaking of which, I did manage to stay long enough to have a beer on the Foundation (thanks!), and chat with Christopher Nagy from Dexterra/Antenna Software, who made a quick ad hoc demo to Ian and myself of their Eclipse/GEF-based tool for authoring multiplatform mobile applications. Very impressive!

As constructive criticism, I do agree with Bjorn that the format could use some tweaking. I sure had to miss some very promising presentations. Maybe with two presentation formats, a longer (for instance, 40-50 mins) and a shorter one (20-25 mins), we wouldn’t need two tracks. I am not sure presenters who came from Europe would have come had they had a shorter slot though. That being said, I was very satisfied with the event overall and am sincerely thankful to IBM Toronto for hosting the event, the Eclipse Foundation for organizing it, all the folks presenting and the companies sponsoring them. Thank you very much! As Lawrence wrote, hope we will see more events like this in the future!

Release 1.4 of the TextUML Toolkit is now available from the update sites, for both Eclipse 3.5+ and 3.4 (by the way, it is possible this will be the last major release targetting Eclipse 3.4, unless someone volunteers to generate and test builds for 3.4).

This is mostly a bug fix release. However, there were some minor notation changes to support stereotypes on dependencies, generalizations and interface realizations, hence the version change from 1.3.x to 1.4.x.

Thanks to Vladimir Sosnin, Attila Bak and fredlaviale for contributing with code and/or bug reports/feature requests. Keep them coming!

As usual, you can find a summary of the changes in the TextUML Toolkit Features page. If you are using the Toolkit, make sure you upgrade soon. If not, what are you waiting for? Install it already!

The TextUML Toolkit 1.3 is now available, 4.5 months after 1.2. If you already got RC1 (1.3.0.20090614…), it is the same build, no need to upgrade again. Otherwise, just point the Eclipse update mechanism to:

http://abstratt.com/update/ - if you are using Eclipse Galileo, or

http://abstratt.com/update/3.4/ - if you are using Eclipse Ganymede.

Please see the feature page for a summary of the evolution of the TextUML Toolkit in terms of features across releases. Some highlights for this release are better integration with other UML tools and support for both Eclipse 3.4 and 3.5.

As usual, bug reports and feature requests are much appreciated. And if you need help, make sure to ask on the user forum.

The TextUML Toolkit Team

The first release candidate towards version 1.3 of the TextUML Toolkit is now available. The feature overview page has been updated to reflect the changes in the 1.3 cycle.

Please give it a try and report any issues you might find. If no serious problems are found with this build, it will be promoted to 1.3 final later this week.

Note that the main update site supports Eclipse 3.5, but there is also an update site for Eclipse 3.4.  The features are the same, the only differences between the two sites are the dependencies (UML2 3.0 and EMF 2.5 on Eclipse 3.5, UML2 2.2 and EMF 2.4 on Eclipse 3.4).

The TextUML Toolkit team welcomes your feedback.

Wow, it is been more than a month since my last post, but I have been busier than ever working on an upcoming MDD-related product (cannot say much now other than that you will hear more about it here first). However, In TextUML Toolkit-land things are looking pretty exciting.

More hands on deck

Vladimir Sosnin has joined the project and has been on a roll contributing many patches, not only bug fixes but design improvements and features too. It is amazing how quickly he has become very comfortable with the TextUML Toolkit code base (Vladimir is certainly a solid developer, but I’d like to think the quality of the code base helped him too). And if that was not good enough, Vladimir is also using the TextUML Toolkit in his daily work around model-driven development, so that should help ensuring the Toolkit has the features its target audience actually needs.

New release in the making

1.3RC1 should be made available during the weekend. It has some shiny new language features, a bunch of bug fixes, better integration with other UML2 tools and support for both Galileo and Ganymede. By the way, shipping code that can handle different incompatible versions of Eclipse has become a little more challenging with P2, as you cannot ship a feature that has bundles that resolve in a mutually exclusive way - it seems you really need two different features for that.

Documentation moved to SourceForge

SourceForge now has support for MediaWiki, which is used to author and serve the documentation for the TextUML Toolkit. In the spirit of strengthening the message that the project should really be considered a community-based effort, I decided to migrate the documentation from the Abstratt web site over to SourceForge.

I guess that does it, at least for now.  Stay tuned.

I have heard the mantra ‘code is model’ several times. Even though I always thought I got the idea of what it meant, only now I decided to do some research to find out where it came from. Turns out that it originated from a blog post that MS’ Harry Pierson wrote back in 2005. It is a very good read, insightful, and to the point.

The idea that gave title to Harry’s post is that whenever we use a simpler representation to build something that is more complex and detailed than we want to care about, we are creating models. 3GL source code is a model for object code. Byte code is a model for actual CPU-specific executable code. Hence code is model.

He then goes to ask that if we have been successfully reaping the benefits of increased levels of abstraction by using 3GLs for decades now, what prevents us from taking the next step and using even higher level (modeling) languages? He makes several good points that are at the very foundations of true model-driven development:

• “models must be precise“- models must be amenable to automatic transformation. Models that cannot be transformed into running code are “useless as development artifacts“. If you like them for conceiving or communicating ideas, that is fine, but those belong to a totally different category, one that plays a very marginal role in software development, and have nothing to do with model-driven development. Models created using the TextUML Toolkit are forcefully precise, and can include behavior in addition to structure.
• “models must be intrinsic to the development process” - models need to be “first class citizens of the development process” or they will become irrelevant. That means: everything that makes sense to be modeled is modeled, and running code is generated from models without further manual elaboration, i.e., no manually changing generated code and taking it from there. As a rule, you should refrain from reading generated code or limit yourself to reading the API of the code, unless you are investigating a code generation bug. There is nothing really interesting to see there - that is the very reason why you wanted to generate it in the first place. Build, read, and evolve your models! Generated code is object code.
• “models aren’t always graphical” - of course not. I have written about that before here. The TextUML Toolkit is only one of many initiatives that promote textual notations for modeling (and I mean modeling, not diagramming - see next point).
• “explicitly call out models vs. views” - in other words, always keep in mind that diagrams != models. Models are the real thing, diagrams are just views into them. Models can admit an infinite number of notations, be them graphical, textual, tabular etc. Models don’t need notations. We (and tools) do. Unfortunately, most people don’t really get this.

The funny thing is that, most of the times I read someone citing Harry’s mantra, it is misused.

One misinterpretation of the “code is model” mantra is that we don’t need higher-level modeling languages, as current 3GLs are enough to “model” an application. The fact is: 3GLs do not provide an appropriate level of abstraction for most kinds of applications. For example, for enterprise applications, 4GLs are usually more appropriate than 3GLs. Java (EE) or C# are horrible choices, vide the profusion of frameworks to make them workable as languages for enterprise software - they are much better appropriated for writing system software.

Another unfortunate conclusion people often extrapolate from the mantra is that if code is model, model is code, and thus it should always be possible to translate between them in both directions (round-trip engineering). Round-trip engineering goes against the very essence of model-driven development, as source code often loses important information that can only exist in higher level models. The only reason people need RTE is because they use models to start a design and generate code, but then they switch to evolving and maintaining the application by directly manipulating the generated code. That is a big no-no in true model-driven development - it implies models are not precise or complete enough for full code generation.

So, what is your view? How do you interpret the “code is model” mantra?

Even though it has always been possible to open models generated by the TextUML Toolkit in UML2-based diagramming tools, until 1.2 the Toolkit assigned new ids to each element every time a model was regenerated. That meant that any diagrams based on the model being regenerated would become invalid as any cross-references from the diagram to the model would be broken.

Starting with 1.3 M1 (test build available from the milestones update site), the TextUML Toolkit is now better compatible with diagramming tools based on UML2. You can edit the source in TextUML and save it to cause model generation to occur, and any existing diagrams should still remain valid.

Here you can see the TextUML Toolkit being used side-by-side with the UML2 Tools graphical editor:

Actually, I found out that UML2 Tools can be a great companion for the TextUML Toolkit because it seems to just do the right thing when it notices the underlying model has been changed externally: new elements show up, removed elements disappear, preserved elements preserve their layout. I tried doing the same with Papyrus 1.11 and unfortunately it does not seem to handle external updates properly. I haven’t tried with other UML2-based diagram editors, so at this point I am not sure which one represents the trend here.

I have been doing some exploratory work around running the TextUML Toolkit’s compiler as a standalone Java application. In other words, without OSGi. You Eclipse/OSGi heads out there might ask: why would anyone want to do that? The answer is: enhanced applicability. Severing ties with the Eclipse runtime/OSGi means the compiler would become usable in other contexts, and by more people. Think Ant or Maven-driven builds, or (the horror!) other IDEs.

The TextUML compiler’s dependencies

The TextUML compiler is not very different from any ordinary 3GL compiler. It reads a bunch of source files and spits another bunch of object files. For reading and writing files, the TextUML compiler uses EFS, the Eclipse File System. For generating the object files, which are UML models, the compiler uses UML2 and EMF.

Luckily, all these components are expected to work on a standalone application, although some restrictions in functionality might apply. At a first glance, one would expect that running the TextUML compiler without OSGi should be quite feasible. But, as I should have learned by now, it is never that simple…

Extension registry without OSGi

The TextUML compiler, and some of its dependencies use the extension registry to receive contributions to their extension points or make contributions to other components’ extension points. Since Eclipse 3.2, the extension registry API provides support for creating registries without OSGi. Basically, you can add any extension and extension points you want, all you need to do is to provide the XML markup for them.

Problem: in a standalone Java application, it is the application’s responsibility to somehow find the plugin manifests and populate the extension registry.

Solution: I started with the example Paul Webster posted on the platform newsgroup almost two years ago. It basically starts from a file system location which it assumes to hold plugins, both on JAR’d and directory form. It will find plugin manifests (plugin.xml), recognize translation resources (plugin.properties), and even discover the bundle name by parsing the bundle manifest (MANIFEST.MF), and use that to populate the extension registry. Pretty cool, thanks PW. I just cleaned-up the code a bit and enhanced it to also find plugin manifests using the application’s classloader. I also had to add support for setting the default extension registry, which is the one other components will get when invoking Platform.getExtensionRegistry() or RegistryFactory.getRegistry(). Finally, I had to implement basic support for creating executable extensions, which was not too hard given that I could assume the entire application is using the same (application) classloader.

EFS without OSGi

Also since 3.2, the Eclipse File System does not require OSGi to operate, however it does require a functional registry as it uses an extension point to allow file system implementations to be plugged in. So, provided one manages to populate the default extension registry, EFS works fine on a standard Java app. No action required here (yay!).

EMF and UML2 without OSGi

EMF has long been advertised as being mostly functional when running in non-managed mode. However, when running in an standalone app, EMF does not process extensions to its extension points (such as resource factories, metamodel packages and URI mappings), so a standard Java application needs to explicitly initialize EMF, which is clearly suboptimal.  That is because EMF only processes contributions to its extension points right during bundle activation. There is no alternative way to trigger processing of the registry (see bug #271253), which sucks, given that the registry is there just waiting to be used. With no OSGi, there is no such thing as bundle activation, and thus EMF goes into autistic mode. This is also true for UML2 (not surprisingly, as they share many implementation traits), the main difference being that UML2’s extension points are much less used than EMF’s.

Problem: Ecore won’t process the extension registry when running in a standalone Java application.

Solution: Change Ecore so it allows clients to explicitly trigger processing of the contributions to Ecore’s extension points. My local hacky solution was to make Ecore’s extension registry parsers to be publicly visible so any client could invoke them.

‘platform:’ URLs without Equinox

Extensions to Ecore’s URI mapping extension often translate to ‘platform:’ URLs, which are another common Eclipse-ism, and thus not supported in plain Java applications.

Problem: No support for ‘platform:’ URL schemes  in standalone mode.

Solution: I implemented a simple URL stream handler for the ‘platform’ protocol. The current implementation complete ignores the path component that determines what bundle the resource is in. That is clearly something that needs to be improved, but should not be too hard.

Conclusion

Well, it wasn’t really a walk in the park, but other than the issue that requires a change in EMF (bug #271253, which I am hoping could be addressed for Ganymede Galileo),  I am pretty happy with the results of this exploration.

I made all the code I wrote (including my version of Paul Webster’s registry loader) available on the TextUML Toolkit’s SVN repository on SourceForge. Feel free to use it and submit improvements. I wonder if this sort of stuff could find a home in Eclipse.org, as I think many people currently developing for non-OSGi targets would like to take advantage of some great OSGi-agnostic Eclipse APIs.

I decided it was time to start using Eclipse 3.5 before it went RC or else if I find any blockers there won’t be time left for them to get fixed before the next release this Summer. I have been on the other side of the fence and know how frustrating it is when people only really start reporting bugs at the very end of the release cycle.

After I installed the 3.5 M6 SDK, I decided to install the TextUML Toolkit 1.2…

Nothing to install?

First surprise: no features would show on the update site! WTH? Well, turns out I had the Update UI to show available features grouped by category, but the TextUML Toolkit update site does not use categories. Unchecking the option to group by categories shows the four features in the TextUML Toolkit update site as it was usual in 3.4. Phew… I was just about to enter a bug report against the Eclipse update component (a.k.a. p2), when I found out that that unintuitive UI behavior has been recently addressed and the next milestone won’t show this problem any longer.

A roadblock

I managed to install the TextUML Toolkit, and that brought along EMF and UML2, which are required features. Since, at this time, the TextUML Toolkit does not specify version range for its dependencies, the latest versions of EMF and UML2 were automatically installed by Eclipse. That should be fine, I thought, as one of the Eclipse development key mandates has always been backward compatibility. But this time around that was not the case: the TextUML builder was failing to compile a TextUML source file that was making use of template parameters. Turns out the UML2 API around templates has changed in its version 3.0. Before (in UML2 2.2), a template parameter substitution could have multiple formal and actual parameters. Now it can have only one of each, and thus the TextUML Toolkit is (partially) broken in 3.5.

So much for core values, you might be thinking? Well, to be fair, this is a bit of a fringe case. The UML2 API is an Eclipse component, and as such should strive for backward compatibility too. However, it is also a high-fidelity rendition of the UML specification published by the OMG. In this case, the OMG fixed a bug (#9838) in the spec, and as often is the case with UML, that resulted in a change that was not backward compatible. If the OMG promotes changes that are not backward compatible, the UML2 team does not have much of a choice: in order to continue to closely implement the spec, it has to break the Eclipse guidelines.

And neither do I. For the TextUML Toolkit 1.2, I will have to issue a maintenance release (1.2.1) that will explicitly depend on UML2 2.2, thus avoiding the new version, and probably becoming incompatible with other UML modeling packages that only run on Galileo and UML2 3.0. For the next release of the TextUML Toolkit (1.3), I will have to adopt the new API and explicitly depend on UML 2 3.0.

That is how life goes… for some reason, I kind of feel like a flea crawling on the back of an elephant.

I strongly believe queries are an essential part of a domain model. As such, in our quest to have (UML) models that can fully (yet abstractly) describe object models for the common enterprise applications, we cannot leave out first class support for queries.

But how do you do queries in UML? The obvious answer seems to be OCL, but that is not the approach I am taking as OCL and UML have serious interoperability/duplication issues. Instead, I took the  middleweight extension approach.

First, we model a protocol for manipulating collections of objects (showing only a subset here):

class Collection specializes Basic
  operation includes(object : T) : Boolean;
  operation isEmpty() : Boolean;
  operation size() : Integer;
  operation exists(predicate : {(:T) : Boolean}) : Boolean;
  operation \any(predicate : {(:T) : Boolean}) : T;
  operation select(filter : {(:T) : Boolean}) : T[*];
  operation collect(mapping : {(:T) : any}) : any[*];
  operation forEach(predicate : {(:T)});
  operation union(another : T[*]) : T[*];
  (…)
end;

That protocol is available against any collection of objects, which in UML can be obtained by navigating an association, reading an attribute, invoking an operation, obtaining the extent of a class (remember Smalltalk’s allInstances), anything where the resulting value has multiplicity greater than one.

Note most of the operations in the Collection protocol take blocks/closures as arguments. Closures are used in this context to define the filtering criterion for a select, or the mapping function for a collect.

For instance, for obtaining all accounts that currently do not have sufficient funds, this method would do it:

static operation findNSFAccounts() : Account[*];
begin
    return Account extent.select(
        (a : Account) : Boolean {return a.balance < 0}
    );
end;

Note the starting collection is the extent of the Account class. That is very similar to what is done in the context of query languages for object-oriented databases, such as OQL or JDOQL. We then filter the class extent by selecting only those accounts that have a negative balance, by passing a block to the select operation.

When mapping that behavior to SQL, we could end up with a query like this:

select _account_.* from Account _account_ where _account_.balance < 0

Another example: we want to obtain all customers with a balance above a given amount, let’s say, to send them a letter to thank them for their business. The following method specifies that logic:

static operation findBestCustomers(minBalance : Real) : Customer[*];
begin
    return (Account extent.select(
          (a : Account) : Boolean { return a.balance >= minBalance }
    ).collect(
          (a : Account) : Customer { return a->AccountOwner->owner }
    ) as Customer);
end;

Note that we start off with the extent of Account class, filter it down to the accounts with good balance using select, and then map from that collection to a collection with the respective account owners by traversing an association using collect.

If that was going to be mapped to SQL, one possible mapping would be:

select _customer_.* from Account _account_
    inner join Customer _customer_
        on  _account_._accountID_ = _customer_._customerID_
    where _account_.balance >= ?

Much of this can be already modeled if you try it out with the TextUML Toolkit 1.2. But, you might ask, once you model that, what can you do with UML models containing queries like the ones shown here?

Since the models are complete (include structure and behavior), you can:

1. Execute them. Imagine writing automated tests against your models, or letting your customer play with them before you actually start working on the implementation.
2. Generate complete code. The generated code will include even your custom queries, not only those basic ones (findAll, findByPK) code generators can usually produce for you.

If you would like to see tools that support that vision, keep watching this blog.

So, what is your opinion?
Do you see value in being able to specify queries in your models? Is this the right direction? What would you do differently?

The TextUML Toolkit 1.2 is now available, 5 months after 1.1, when it first became an open source project. If you already got RC2 (1.2.0.200902011417), it is the same build, no need to upgrade again. Otherwise, just point the Eclipse update mechanism to:

http://abstratt.com/update/

Please see the feature page for a summary of the evolution of the TextUML Toolkit in terms of features across releases.

As usual, bug reports and feature requests are dearly appreciated. And if you need help, make sure to ask on the forum.

Acceleo is a cool open-source code generation tool that has great integration with the Eclipse IDE and EMF-based metamodels. The tool has a strong emphasis on simplicity and ease of use, which, for an open source development tool, is really a breeze of fresh air.

The Acceleo website includes a repository of code generation modules, which are extensions to the tool that target generation for specific platform/languages, such as .Net (C#/NHibernate), Java (Hibernate/Struts/Spring), Python, PHP, C, Zope etc. Of course, you can also develop your own modules, using Acceleo template editors with metamodel-driven content assist, and live sample generation.

Most of the modules in the Acceleo repository take UML2 compatible models. That means you can use the TextUML Toolkit for quickly creating your UML models using the TextUML textual notation, and then use Acceleo to generate code from them.

One of the most mature code generation modules in the Acceleo repository is the UML2 to Java EE module, which can generate code for Spring, Struts and Hibernate-based Java applications from UML2 models. A step-by-step guide would be too much for this post, but if you want to explore generating Java EE code from UML models you create using the TextUML Toolkit, here are some pointers:

Get the tools. First of all, using Eclipse 3.4, install all features from the following update sites:

• TextUML Toolkit - http://abstratt.com/update/
• Acceleo code generator - http://acceleo.org/update/
• Acceleo code generation modules - http://acceleo.org/modules/update

Once the install is complete, allow Eclipse to restart for the new plug-ins to become available.

Create your UML models and profiles. Create a project for your UML models using the TextUML Toolkit. For an example of how to do that, see the TextUML Tutorial. You will need to define in your model project a profile where you declare the stereotypes that you will use to annotate your modeled classes, to drive code generation (see how here)

Create your Acceleo generator project. The Acceleo website has plenty of documentation on how to create Acceleo code generation projects. Some pointers:

• main documentation page (instalation and tutorials)
  
• UML to JEE module documentation
  

Note that this module has a bug in which it is based on a profile with an invalid UML name which won’t work with the TextUML Toolkit out of the box. Instead of using the profile shipped with that module, you can then override the default profile and stereotypes using a properties file at the root of your generator project as shown here so to direct it to your own profile and stereotypes. You can also find a more structured guide for using Acceleo and the TextUML Toolkit together here. Even though that tutorial uses a customized version of the JEE module, it can still be helpful.

As usual. If you need help generating code from UML models using the TextUML Toolkit and Acceleo, feel free to ask for help here, or in the user forum.

A new RC build of the TextUML Toolkit is now available. It has one bug fix since RC1. Basically, when rendering stereotypes, the metaclasses extended by the stereotype were not being shown. Not really critical, but isolated and safe enough to be fixed now. Pending any last minute bug reports by the community, it is likely this build will be promoted to 1.2 release early this week.

Also, while testing, I noticed that the Pet Store example was triggering a known Graphviz issue with associations navigable both ends, so I updated the petstore_models project so the relationship between Title and Payment was navigable only in one direction (Title -> Payment). I recaptured the class diagram images showing on that page using the Image Viewer “Save to File” function instead of screenshot sections.

Just trigger a software update for the TextUML Toolkit to get RC2.

Yikes, it happened again. A user reported that the TextUML Toolkit 1.2 RC0 build announced earlier this week wouldn’t run on Java 5 VMs (Mac users would be the most affected). This has just been fixed (one bundle was being compiled against Java 6) and a new release candidate is now available from the update site. If you too were seeing “java.lang.UnsupportedClassVersionErrors” running RC0, just go ahead and update to RC1.

The third milestone build and first release candidate of the TextUML Toolkit, the IDE for textual UML  modeling, is now available from the update site.

The feature page shows all the new features in this new release, but here they are:

• primitive types
• data types (a.k.a. structs)
• required extensions for prototypes
• behaviour modeling (a.k.a. action semantics)
• shorthand notation for aggregation and composition
• abstract stereotypes
• cross-project references

As you can tell, most of the work in the 1.2 release cycle was towards extending the TextUML notation with support for UML.

There were also several bug fixes, one of them being the first to be addressed by an external contributor (thanks, Massimiliano!).

If no serious issues are found with this milestone build, it will be promoted to 1.2 final by the next weekend. So, if you are using a 1.1.* build, make sure you upgrade it to a 1.2 release candidate build and start smoke testing with your usual workflows, and report any bugs you find.

UML is known to be a huge language, and that has two problems: it is too complex, having way more features than most applications will ever need, and can still be insufficient, as no single language will ever cover everybody’s needs.

In the article “Customizing UML: Which Technique is Right for You?”, James Bruck and Kenn Hussey (both from the UML2 team) do a great job at covering the several options for extending (or restricting) UML (James also made a related presentation at last year’s EclipseCon, together with Christian Damus, of Eclipse OCL fame). Cutting to the chase, these are the options they identify:

• using keywords (featherweight extensions)
• using profiles, stereotypes and properties/tagged values (lightweight extensions)
• extending the metamodel by specializing the existing metaclasses (middleweight extensions)
• using package merges to select the parts of UML you need (heavyweight extensions)

Each option has its own strengths and weaknesses, as you can see in the referred article/presentation. At this time, the TextUML notation supports two of those approaches: profiles and metamodel extensions.

Adding closures to UML

Even though profiles are the most popular (and recommended) mechanism for extending UML, it is not enough in some cases/applications. That has been the case in the TextUML Toolkit, for instance, when implementing closures in the TextUML action language (yes, the Toolkit eats its own dog food).

According to the wikipedia entry, “a closure is a function that is evaluated in an environment containing one or more bound variables. When called, the function can access these variables. ”

It really makes sense to (meta) model a closure as some kind of UML activity, which is basically a piece of behavior that can be fully specified in UML. Methods, for instance, are better modeled in UML as activities. Activities are composed of activity nodes and actions, which are similar to blocks of code and instructions, respectively.

The only thing that is missing in the standard Activity metaclass is the ability for a closure to have an activity node from another activity as context, so it can access context’s local variables. So here is a possible (meta) modeling of closures in UML using the TextUML syntax:

[Standard::Metamodel]
model meta;

apply Standard;

(*
  A closure is a special kind of activity that has another
  activity’s activity node as context. A closure might
  reference variables declared in the context activity node.
*)
[Standard::Metaclass]
class Closure specializes uml::Activity
  (* The activity node that provides context to this closure. *)
  reference contextNode : uml::StructuredActivityNode;
end;

end.

Or, for those of you who prefer a class diagram (courtesy of the EclipseGraphviz integration):

Note a model contributing language extensions must be applied the Standard::Metamodel stereotype, and each metaclass must be assigned the stereotype Standard::Metaclass.

Of course, there is no point in being able to metamodel closures, if there is no way to refer to them. We need a kind of type that we can use to declare variables and parameters that can hold references to closures. That also means we need to be able to invoke/dereference a closure reference, and there is no support for referring to metamodel elements in the UML action language. That means we need more language extensions. But I will leave that to another post. My goal here was to show how simple it is to create a simple UML metamodel extension with the TextUML Toolkit.

What about you, have you ever needed to extend UML using a metamodel extension? What for?

No tool is an island. That is even more important when we are talking about highly focused single-purpose tools such as the TextUML Toolkit. As you probably know, the TextUML Toolkit is a tool for UML modeling using a textual notation, but that is about it. The TextUML Toolkit itself won’t help if you need features such as code generation, reverse engineering or graphical modeling/visualization. That might look as a negative thing to some, but that is by design. I am a strong believer of separation of concerns, component-based software and using the best tool for the job, and that is reflected in the design of the Toolkit.

This post will describe how to use models created by other UML2-compatible modeling tools from models you create using the TextUML Toolkit. I plan to cover other areas of integration in future posts.

Reading models created by other UML tools using the TextUML notation

If you have the TextUML Toolkit installed, one of the editors available for UML files is the TextUML Viewer. As the name implies, it is not really an editor, i.e., you cannot edit models with it, just visualize them using the TextUML notation. But it is an useful tool for reading UML models you don’t have the source for, i.e. models created by other UML2 modeling tools.

Using models created by other tools…

There are a few different ways of using models created by other UML modeling tools from your models created in TextUML.

…by co-location

In this method, you just drop the UML model you want to use to at the root of your TextUML (i.e. MDD) project. All models at the root of the same MDD project are considered to be in the same repository and thus you can make cross-model references by either using qualified names or importing the package and using simple names.

This method is dirty simple, but it forces you to keep the foreign model at a specific location, potentially forcing you to keep multiple copies of the model.

…with project references

In this method (available starting in version 1.2), the UML model you want to use is in a different project than the one you want to refer it from. You just open the properties dialog for your TextUML (MDD) project and add the project providing the UML model you want to use to the list of referenced projects. Now models at the root of that project will also be visible from your TextUML (MDD) project, in other words, they are also seen as part of the same repository.

This method is more powerful than the previous one, as now models can be shared by reference instead of by copying. There is a limitation still: the models you use ought to be part of some project in the workspace, so you cannot refer to models stored at arbitrary locations in the file system or models that are contributed by Eclipse bundles.

…by explicitly loading them

For this method, you use the load directive to load an external model located by a URI.

This method allows you to load any model, provided its location can be represented as a resolvable URI. That is the case of any file system path, or Eclipse platform URLs. The caveat is that some URIs such as file system URIs are not portable, so they are are bound to be invalid on other machines.

The entire truth…

…is that even if you are using only the TextUML Toolkit for building UML models, these are the same mechanisms for creating models that make cross-package references (see also the TextUML Guide). For the TextUML Toolkit, all UML2-compatible models are equal, no matter how they were created.

The second milestone build towards TextUML Toolkit release 1.2 is now available from the milestone update site. Get it while it is hot.

This milestone adds support for some UML language features:

• required extensions for stereotypes
• data types
• primitive types

But what is really exciting is that this milestone is also the first build that includes a contribution from a new member of the TextUML Toolkit team: Massimiliano Federici provided a  patch that squished bug 2127735 (revision 194). Kudos to Massimiliano, his contribution was greatly appreciated, and it seems it might just be the first of many!

Yesterday I checked in support for UML primitive types in the TextUML Toolkit. As an example of the syntax, here is the UMLPrimitiveTypes model, shipped in Eclipse UML2, rendered by the TextUML Source viewer:

[Standard::ModelLibrary]
model UMLPrimitiveTypes;

apply Standard;

primitive Boolean;

primitive Integer;

primitive String;

primitive UnlimitedNatural;

end.

As you can see, primitive types are declared using the keyword ‘primitive’, and cannot specialize other types or have structural features (thus there is no ‘end’ terminating the type declaration). To be honest, I am not sure this is the intended semantics, as the UML specification does not seem to explicitly disallow that.

Here is the breakdown of the change sets (r188-191):

• automated tests (r190)
• parser and model generation (r191)
• textual renderer (r189)
• editor (r188)

To be frank, the only test case added was quite trivial:

public void testPrimitiveType() throws CoreException {
  String source = "";
  source += "model someModel;\n";
  source += "primitive Primitive1;\n";
  source += "end.";
  parseAndCheck(source);
  PrimitiveType found = (PrimitiveType) getRepository().findNamedElement(
    "someModel::Primitive1", IRepository.PACKAGE.getPrimitiveType(), null
  );
  assertNotNull(found);
}

But it is a good start. It ensures parsing works, and the model generated has the intended element created under the right parent package.

Any suggestions of what UML feature to cover next? And what is your take? Can UML primitive types have structural features or specialize other types/implement interfaces?

(By the way, if you want to understand how the TextUML Toolkit is implemented, feature posts like this are a good starting point)

Just checked in a new feature in the TextUML Toolkit: support for data types (a.k.a. structs). This is an example of a data type declaration:

datatype UserName
  attribute firstName : String;
  attribute lastName : String;
end;

You can declare operations and specialize other classifiers as usual.

Change set

Here are the individual changes per plug-in (r177-r186):

• automated tests (180 and 185)
• parser and model generation (181, 184 and 186)
• textual renderer
• editor

There, nice and easy. Well, actually, I ended up doing a second commit because I forgot to ensure a data type specializes only other data types. But now that has been taken care of.

As usual, suggestions of UML features to support in the TextUML Toolkit are most welcome.

Great discussion over @ Slashdot: Is Open Source Software a Race To Zero?

I really think the open source approach has lots of benefits, for the software itself and all parties involved. However, I would say it will probably take a decade before sound business models based on open source are really understood and start to become mainstream.

At this point in time, (as most people) I still think it is considerably harder/trickier to make money developing software as open source than it is with closed source. At least for small companies. A few reasons:

• reduced barrier to entry for new competitors as they can easily leverage the fruits of your hard work. Even more so if you choose a more liberal license such as a BSD, EPL or Apache (JBoss and MySQL use GPL, for instance).
• lower profit margins, if you decide to adopt a services-based business model instead of one based on selling product licenses, which is a common approach.
• the overhead of maintaining the open source software while developing the closed source extensions or providing the related services, the very activities that will actually make money, could be unbearable.

The TextUML Toolkit is open source (EPL) since release 1.1. The decision of making the TextUML Toolkit open source was based on the fact that I (a.k.a. Abstratt Technologies) never intended to make any money directly off of it, wanted to attract external contributions and maybe get some visibility to other future offerings. But I wouldn’t have done it if I had any plans of selling the TextUML Toolkit as a product on its own.

Well, I am interested in your thoughts. Do you know of cases of small companies making good money from developing and selling open source software (using liberal licenses such as the EPL)?

I would like to see the TextUML Toolkit as an Eclipse MDT subproject. Not long ago, I talked to Kenn Hussey and Ed Merks (they lead the UML2 and EMF projects, respectively) about the idea of proposing the Toolkit to the EMO and they both liked it (Ed actually suggested the idea in the first place). However, I was concerned that just one guy (yours truly) working on the project on and off in his spare time with no user community didn’t look very promising, and Kenn promptly agreed, so it was decided that it was important to get other people on board first.

With the intent of starting to gather some sort of community and hopefully contributors, I decided to release version 1.1 as EPL. In the first couple of weeks after that, I noticed a significant spike in interest (page hits, issues opened, forum activity). But then everything went back to how it was before: today, there is no evidence anybody is using the tool, and I am still the only committer in the project.

So, this is a call (or a cry) for contributors: if you like the textual approach to UML modeling proposed by the TextUML Toolkit, would like to help putting together a proposal, and have some amount of time/resources to commit to the project in the long(ish) run, I am really eager to hear from you.

Things that are in scope for the project:

• broader notation coverage of UML features
• richer IDE support: content assist, search/hyperlinking, refactoring
• better integration with graphical UML tools

If you are interested, feel free to contact me via this blog, the Toolkit forum or e-mail (rafael at abstratt.com).

Just checked in a new feature in the TextUML Toolkit: required extensions for stereotypes (honestly, I didn’t know about that feature in UML until I read this post on the Eclipse UML2 newsgroup).

The following is a stereotype extending two metaclasses (uml::Class and uml::Operation):

profile my_profile;

import uml;

stereotype foo extends Class, Operation required
end;

end.

In the example above, the extension of Operation is required, the extension of Class is not.

Change set

The change set to implement required extensions in the TextUML Toolkit (issue #2266268) was quite small (btw, kudos to the UML2 project for providing the best API for UML out there).

Here are the individual changes per plug-in (r153-r156):

• automated tests
• parser and model generation
• textual renderer
• editor

Any other UML feature you would like to see exposed in the TextUML notation? Suggestions are welcome.

The first milestone build of the next TextUML Toolkit release is now available from the milestone update site. This preview build is the first to include support for modeling behavior using action semantics. I hinted at this capability here before, and I plan to cover action semantics in the TextUML notation in following posts. But most people will get the gist of the notation from the examples below:

Here is an example of a UML model of an Account class represented in TextUML:

model bank;

import base;

class Account
    attribute accountNumber : String;
    attribute balance : Integer;

    operation withdraw(amount : Integer);
    begin
        self.balance := self.balance - amount;
    end;    

    operation deposit(amount : Integer);
    begin
        self.balance := self.balance + amount;
    end;

    static operation newAccount(number : String,owner : Client): Account;
    begin
        var newAccount : Account;
        newAccount := new Account;
        newAccount.accountNumber := number;
        newAccount.balance := 0;
        link ClientAccount(owner := owner, accounts := newAccount);
        return newAccount;
    end;
end;

class Client specializes Object
    attribute name : String;
    static operation newClient(name : String): Client;
    begin
        var newClient : Client;
        newClient := new Client;
        newClient.name := name;
        return newClient;
    end;
end;

association ClientAccount
    navigable role owner : Client[1];
    navigable role accounts : Account[0, *];
end;

end.

And here an example of a test driver ‘program’ (note the use of a closure for looping through a collection of objects):

package test;

apply base_profile;

import bank;
import base;

class TestDriver
  [entryPoint]
  static operation run();
  begin
      var john : Client, mary : Client,
             account1 : Account, account2 : Account, account3 : Account;
      john := Client#newClient(”John Doe”);
      mary := Client#newClient(”Mary Doe”);

      Console#writeln(”Created: “.concat(john.name));

      account1 := Account#newAccount(”1234-1″, john);
      account2 := Account#newAccount(”1238-2″, mary);
      account3 := Account#newAccount(”2231-7″, john);

      Console#writeln(”account owner: “.concat(account1->ClientAccount->owner.name));
      Console#writeln(”account number: “.concat(account1.accountNumber));
      Console#writeln(”initial balance is: “.concat(account1.balance.toString()));

      account1.deposit(2000);
      Console#writeln(”after deposit, balance is: “.concat(account1.balance.toString()));

      account1.withdraw(500);
      Console#writeln(”after withdrawal, balance is: “.concat(account1.balance.toString()));

       /* Now show information for all accounts. */
  	Account extent.forEach(
          (a : Account) {
              Console#writeln(”*******”);
              Console#writeln(”Owner: “.concat(a->ClientAccount->owner.name));
              Console#writeln(”Number: “.concat(a.accountNumber));
              Console#writeln(”Balance: “.concat(a.balance.toString()));
          }
      );
  end;
end;

end.

And here is the output of the test driver program, produced by running it on the Libra UML runtime (not part of the TextUML Toolkit):

Created: John Doe
account owner: John Doe
account number: 1234-1
initial balance is: 0
after deposit, balance is: 2000
after withdrawal, balance is: 1500
*******
Owner: Mary Doe
Number: 1238-2
Balance: 0
*******
Owner: John Doe
Number: 1234-1
Balance: 1500
*******
Owner: John Doe
Number: 2231-7
Balance: 0

Alternatively, one could have generated 100% of the code for a target platform of choice, given that all the information necessary for that is in the model. Note that code generation is not part of the TextUML Toolkit.

Do you want to give it a try? Install M1 from the milestone update site. You can also fetch the example projects from here.

It is certainly a rough stone. I am counting on the community feedback to figure out what areas need to be smoothed first. Please provide your feedback or ask questions on the TextUML Toolkit forums.

Do you know what UML can do for you? I mean, did you know that UML models can actually do things?

One of the least known features of UML is that you can model detailed imperative behavior. The UML “instruction set” can do things like:

• create and destroy objects
• create and destroy links (associations) between objects
• read and write attributes and local variables
• invoke operations and functions
• throw and catch exceptions
• conditional statements
• loops

That is quite amazing, isn’t? And all that while still preserving a high level of abstraction. Such capability is generally referred to as ‘action semantics’. Action semantics provides the basic framework for executability in UML and has been there for quite a while now. It was originally added to the spec, first as patch, in UML 1.5 (2003), and then more seamlessly integrated into UML 2.0 and following spec releases.

Action Semantics and TextUML

An even more well-kept secret is that the TextUML notation supports UML action semantics and thus the creation of fully executable UML models. This support is not yet shipped as part of the TextUML Toolkit, but will be in the next release. Meanwhile, if you want to give it a try or take a closer look, you will have to grab the source from the SVN repository.

I plan to go into more details in the near future, but just to wet your appetite, here is one example of an executable UML model described in the TextUML notation:

package hello;

apply base_profile;
import base;

class HelloWorld
    [entryPoint]
    static operation hello();
    begin
        Console#writeln(”Hello, World”);
    end;
end;

end.

Cool, isn’t? If you had a UML runtime, this model could be executed even before you made a decision about what platform to target. Also, if your code generator were action semantics aware, you could trigger code generation for the target platform(s) of choice, with the key difference that you could achieve (or get very close) to full code generation, as the model now also describes behavior. No more of that monkey business of having to edit the generated code and manually fill in all those /* IMPLEMENT ME! */ methods.

Do you think this has value? Would you want to work with a tool that supported that? I am really keen on knowing your opinion.

I posted this earlier this week on the UML2 newsgroup, thought I would share it here too…

I published a TextUML rendition of the UML 2.1 metamodel that is shipped by Eclipse UML2 here (warning: 5.9k lines, 370Kb of text). It starts like this:

(...)
model uml;

apply Ecore;
apply Standard;

import ecore;

(* A comment is a textual annotation that can be attached to a set of elements. *)
[Standard::Metaclass]
class Comment specializes Element
    (* Specifies a string that is the comment. *)
    [Ecore::EAttribute(isID=false,isTransient=false,isVolatile=false,isUnsettable=true,annotations=[])]
    public attribute body : String;
    (* References the Element(s) being commented. *)
    public attribute annotatedElement : Element[0, *];
end;
(…)

Thought it could be useful to anyone wanting to have a quick look at the UML metamodel. The TextUML renderer does not support all UML element types, so some elements might be missing/incomplete.

I think that is a nice demo of the textual browsing capabilities in the TextUML Toolkit. Of course, much more could be done in that area. If you feel like lending a hand, any help (bug reports included) will be much appreciated.

Shorthand notation for both composite and aggregate associations has just been checked in (r99-r100). It follows the same spirit as the existing shorthand for plain associations (a.k.a. references).

composition <end-name> : <referenced-type-name>;

or

aggregation <end-name> : <referenced-type-name>;

That will result in a new unnamed association with two member ends, one named, owned by the declaring classifier, with composite or shared aggregation type, and another unnamed, owned by the association itself.

Change set explained

When adding a new feature to the notation, the typical change set contains:

• updates to the affected grammar production rules
• implementation of the corresponding model generation handling code
• a few test cases.

In the case of the features presented in this post, the grammar change was quite simple (nicer view):

--- trunk/plugins/com.abstratt.mdd.frontend.textuml.core/textuml.scc	2008/09/16 05:47:13	99
+++ trunk/plugins/com.abstratt.mdd.frontend.textuml.core/textuml.scc	2008/09/16 05:47:20	100
@@ -341,7 +341,9 @@

   attribute_decl = attribute identifier colon type_identifier optional_subsetting semicolon ;

-  reference_decl = reference identifier colon type_identifier optional_subsetting  semicolon ;
+  reference_decl = reference_type identifier colon type_identifier optional_subsetting  semicolon ;
+
+  reference_type = {association} reference | {composition} composition | {aggregation} aggregation ; 

   optional_subsetting = subsets qualified_identifier | {empty} ;

In other words, where one could declare a reference, one can now declare also a composition or an aggregation (gotta love the readability of SableCC grammars…).

The corresponding model generator (a.k.a. compiler) changes were quite trivial as well, even more so if you consider I inadvertently checked in a fix to an unrelated bug around comments (just ignore the changes in lines not in the 300’s).

In terms of lines of code, the bulk of the changes were in the test class for associations, where I added three test cases. I had postponed writing tests for the reference shorthand notation, so I took this opportunity to write a test for it too.

As most test cases in the TextUML Toolkit test suite, the new test cases in AssociationTests have the following layout:

• one or more compilation units with TextUML source code are declared
• source code is compiled and the resulting errors verified (most test cases won’t expect errors)
• the resulting model is checked - were the expected elements created? Do they have the expected features?

Talking about tests

The TextUML Toolkit has a modestly sized test suite (~130 test cases) at this time. It could use dozens, probably hundreds more, but most features are covered to so some extent.

However, as important as coverage, is how much one can learn about the piece of software being tested by reading its test suite. And here is where I believe the TextUML Toolkit’s test suite shines. For example, by reading the test classes, one could (maybe more effectively than by reading the notation guide), learn how the following UML features are exposed by the TextUML notation:

• classes and structural features
  
• packages, imports, profiles
• associations
• multiplicity
• template classes

Trivia: can you find out from the test suite the difference between a private and a public package import? Give it a try and let me know if I am lying… by the way, the notation guide does not cover that yet, although the UML specification, of course, does.

I often see the TextUML Toolkit being compared to tools that produce UML diagrams from textual descriptions. Examples of tools like that are ModSL, MetaUML and UMLGraph. But that doesn’t really make sense, and here is why: these tools produce diagrams from text. The TextUML Toolkit produces models from text. But what is the difference between models and diagrams?

According to Wikipedia:

• A diagram is a 2D geometric symbolic representation of information according to some visualization technique.
• A model is a pattern, plan, representation (especially in miniature), or description designed to show the main object or workings of an object, system, or concept.

Note that even though both terms are defined around the word “representation”, the term “diagram” implies graphical visualization, whereas the term “model” admits any kind of media, basically because models have no concrete form per se.

Now, please, if you are not convinced yet, read aloud 5 times: MODELS ARE NOT DIAGRAMS!

If that didn’t work, well, maybe the facts below will help:

• models, not diagrams, are the subject matter of model-driven development.
• models, not diagrams, can be validated.
• models, not diagrams, can serve as input to code generation.
• models, not diagrams, can be automatically generated from reverse engineering source code.
• models, not diagrams, can be executed.

Even though diagrams are commonly used for representing models, they are not the only way, and non rare not the most appropriate one (yes, I am talking again about the virtues of textual notations, but I won’t repeat myself).

P.S. Maybe it helps adding to the confusion the fact that the TextUML Toolkit has an optional feature that will generate class diagrams automatically from the UML models created with it. However, that is just an optional, loosely integrated feature, and it is definitely not the Toolkit’s thing. Weirdly enough, from my observation, that feature is the main reason most people become interested in the TextUML Toolkit. Well, go figure.

TextUML Toolkit 1.1 is out! This is the first release after the TextUML Toolkit became an open source project. Besides the adoption of the Eclipse Public License, these are the new features that were added in 1.1:

• more UML features exposed by the textual notation: abstract operations and parameter direction modifiers
• more diagram layout controls (compartments, elements across packages)
• support for exporting the class diagram to a PNG or JPG image file (actually, an EclipseGraphviz feature, also available for other graphical content providers)

Also, the TextUML Toolkit is not available any longer as a standalone download. You need to install Eclipse 3.4 first  (3.3 support was dropped) and then install the TextUML Toolkit using the new smart Software Updates mechanism in Ganymede. See new install instructions here.

As usual, feedback is most welcome - blog, issue tracker or forum, whatever option works best.

Since I started working on the TextUML Toolkit more than a year ago, I have been asking myself whether it would make sense to make it available under an open source license.

Open sourcing a product is a tough decision. Once you take that road, there is no way back, at least not without risking a backlash from the community (of course, if you managed to build a community). And even though there are more and more examples of successful businesses built on top of open source offerings, they are still the exception. However, from day one, my plan for the Toolkit has always been to give it away for free. Going from “free-as-in-beer” to “free-as-in-speech” is not nearly as traumatic.

I resisted to the idea while I was working on releasing version 1.0, as I considered it as potentially distracting and of questionable value, as then I knew exactly what I wanted to ship and how to get it done. However, now that 1.0 is out of the way, it seems the right thing to do. The first release provided a good starting point, but the project certainly needs more hands on deck to get to the next level. It is also clear that an open source license means a lot when you are catering to a developer audience.

So, you heard it here first: the next release of the TextUML Toolkit will be licensed under the Eclipse Public License. The source code is already available on SourceForge, and user forums and issue tracking are now also hosted there.

Joining the Eclipse Modeling project (more specifically the MDT subproject) is an option for the future, depending on whether the project succeeds in attracting other contributors.

Using the tool, spreading the word, asking and answering questions on the forum, reporting problems and requesting features are all great ways of helping. Regarding new features, the project needs help on two main fronts: broader coverage of UML (state machines, activities), and better IDE features (such as content assist, templates, symbolic search and refactoring). If you like the textual notation approach, the tool, and feel like you could lend a hand, please do, the TextUML Toolkit needs you!

I just completed the code for supporting parameter direction modifiers. When this feature makes into the next build, modelers will be able to choose for named parameters any of the standard parameter direction kinds: out, inout, or (the default) in. By the way, the syntax for specifying return types remains the same. Here is an example:

  operation op1(in p1 : String, out p2 : String);

Java developers might consider this feature unnecessary as there is only one way of passing parameters in Java, but for distributed applications (such as those using CORBA or web services) these modifiers are quite relevant.

The corresponding support for rendering operation parameter direction kind modifiers has been added to the TextUML model viewer (decompiler) and EclipseGraphviz graphical rendering component.

This is the first new feature since version 1.0 was released.  The impact of implementing it was quite minimal to the code base, so I am looking forward to implementing the next notation feature. The question is: what feature? Any suggestions?

One potential downside people often point out about using TextUML as a notation for UML is that it is yet another language to learn. But that is not really a well founded argument. TextUML is not a full-blown language, it is just an alternative notation for UML, the de facto standard language for modeling. The language semantics of UML are defined in terms of an abstract syntax, and even though the specification includes sections about the graphical notation, it clearly supports the idea of alternate concrete syntaxes.

Moreover, we really shouldn’t care much about the actual notation being used, be it the standard graphical notation, TextUML or any other textual notation. I surely don’t. Regardless what notation you use for creating UML models, in the end there is only one language. All you know about the semantics of UML model elements is still true no matter what syntax you choose (for instance, if you know your UML, you should easily become productive with the TextUML Toolkit by just glancing over the notation guide now and then). In fact, I predict a time where people will want to move between different notations across tasks and time. Also, in the same team, different people will be collaboratively creating UML models using different notations.

This will only be possible because supporting a new concrete syntax is much simpler than supporting a whole new language (by the way, that is the same reason why I believe UML-based DSLs to be a better option than homegrown proprietary DSLs, but I digress). Any reasonably good programmer armed with a parser generator and knowledge of the metamodel should be able to write a compiler for a textual notation for UML, and Eclipse makes it really easy to provide basic IDE features such as those you see in the TextUML Toolkit. Also, there are tools in the horizon such as IMP and TMF that will make these tasks really a breeze.

Meanwhile, you can stick with what is here today.

I just uploaded the first interactive presentation showing how to install and configure the TextUML Toolkit on Eclipse 3.4. It starts with a plain Eclipse Platform Runtime install, and guides the reader through the following steps:

1. making sure you have the right version of Eclipse (3.4)
2. adding the TextUML Toolkit update site
3. installing the TextUML Toolkit and EclipseGraphviz
4. configuring EclipseGraphviz to point to your Graphviz install
5. opening the Image Viewer view to show models using the graphical notation
6. creating an empty TextUML Toolkit project
7. creating an empty TextUML source file
8. creating a minimal class diagram with a package and a featureless class
9. understanding the edit/compile/visualize cycle

Give it a try and let me know what you think. Blame me for any weird screen transitions. Wink is a great little tool but has a few small quirks that I have yet to master, but the next presentation should look better. Cheers,

Rafael

According to an announcement made on the acceleo-dev mailing list, Acceleo 2.3.0 has been released today. Congrats to the folks at Obeo! The latest bits are already available from Acceleo’s update site, but the download page still shows 2.2.1 as the latest release available.

That is one less excuse for using Eclipse 3.3, which was the latest release supported by Acceleo 2.2.1. An added bonus is that the TextUML Toolkit is much more stable on Eclipse 3.4 due to a nasty concurrency bug fixed in UML2 for the Ganymede release (kudos to Kenn and James!).

I just updated the install instructions for the Pet Store example application. With a new and improved Software Update mechanism (a.k.a. P2), it became much simpler to install the TextUML Toolkit and Acceleo on Eclipse 3.4. For instance, no need to worry about EMF or UML2, they are transparently installed. How cool is that?

I am proud to announce that the TextUML Toolkit reached version 1.0!

It is basically the same as the RC3 build, made available earlier this week, with version numbers updated to reflect the status of release. You can download the TextUML Toolkit 1.0 from here.

Even if it still preserves the same humble look & feel, the TextUML Toolkit has come a long way since the first public milestone was announced here more than a year ago:

• M1 - May 2007
  • website went live
  • first public milestone
• M2 - September 2007
  • graphical class diagram visualization for Windows only (spawned as a brand new open-source project, EclipseGraphviz)
  • support for enumerations
• M3 - March 2008
  • reverse engineering of UML2 models as TextUML source (aka textual browsing)
  • diagram rendering also on Linux and Mac OS/X
  • click-through license
  • better stability and performance
  • website improvements: added user forum (SMF)
• M4 - May 2008
  • duplicate symbols properly reported as compilation errors
  • TextUML source renderer showing nested packages
  • evaluated a few code generators (Acceleo, oAW xPand, EMF JET), chose Acceleo
  • first milestone available via update site
• M5 - June 2008
  • fixed a serious memory leak caused by UML2 caching
  • several bug fixes
  • decoupled the TextUML Toolkit from EclipseGraphviz (EG becoming just a possible integration)
  • website improvements: wiki-based (MediaWiki) documentation area
• 1.0 - July 2008
  • support for applying stereotypes to stereotypes
  • provided a Pet Store-like sample application
  • more, better documentation

On the outreach front: in December, I did a quick presentation of the TextUML Toolkit during the Eclipse DemoCamp in Vancouver, and had the opportunity of doing a longer, more detailed presentation at the VIJUG’s meeting in April. At both opportunities, receptivity to the project was quite good. People seemed very keen on the idea of UML models as text, and I got lots of interesting questions.

In early June, I joined many other fellow mISVers in the 30-day product challenge. Even though I didn’t achieve everything I had set out to do, I am quite happy for having been part of it, as it provided me with the strength and courage to finally ship the first release.

Overall, I am quite happy with the current state of the TextUML Toolkit (or else I would not have declared a release). On the other hand, I confess I am disappointed that interest has not picked up yet, considering it is a free tool that provides real value. Now that there is an example describing how to use the TextUML Toolkit and Acceleo for generating code from UML models (which is the main application of the tool), I hope the value of the tool will become more apparent. And I guess more attention to the marketing side of things won’t hurt.

For the next few months, I will be focusing on a more ambitious project I have hinted at here a couple of times before. During this time, I will be promoting the TextUML Toolkit, writing more documentation and examples, and fixing any bugs users might report, but I do not plan to develop any new features unless there is user demand.

Well, it has been a fun ride, and I appreciate the interest of those of you who have followed at least some part of the journey. Your comments on the blog have been very helpful and encouraging. Thanks a lot!

Cheers,

Rafael

The Pet Store-like model-driven sample application is now available. This initial version contains UML models for a few of the key entities, and generates the domain model classes and their corresponding Hibernate mapping files. I noticed the generated mapping files (or maybe the models) have a few issues and/or missing elements, but as a first stab I am quite happy. Please give it a try. It is a great way example of how the TextUML Toolkit can be used in the context of code generation, in this case, with the awesome Acceleo tool (open-source). Note this is just an example - you should be able to use any UML2-based Acceleo modules (like those available from Acceleo’s module repository) and generate code from any UML models you create using the TextUML Toolkit.

In addition to the sample application, the latest TextUML Toolkit release candidate (RC3) is also now available, both as a standalone download and as an update site, as usual. Work items delivered in this build:

• ticket #182 - associations end up with one single member end
• ticket #183 - cannot define stereotypes on stereotypes
• ticket #167 - provide sample application

To my fellow 30-dayers - yes, its 8 days past the 30 day deadline, but unless I get a serious bug reported during this week, this is it, I am about to achieve my modest goals (yay!) of shipping 1.0 and a sample application (remember, I started working on the TextUML Toolkit quite while ago). The only planned change for 1.0 is basically updating the splash screen to sport the elusive 1.0 version number.

Feedback on RC3 or the sample application is most welcome. As usual, feel free to comment here or on the forums.

Cheers,

Rafael

I finally figured out what was preventing me from exporting the product from Eclipse and worked around the problem. So the TextUML Toolkit RC1 is finally available for download, 4 days after planned.

It turned out the issue that was blocking me was not specific to Eclipse 3.4 RC3. Still, I decided that, until the end of the 30-day challenge, I will continue to use 3.3 to avoid any further surprises. I intend to go back to 3.4 shortly after that.

Another important task that was planned for the first phase (first two weeks) and I have yet to address is the sample application (models + templates). That means some of the less critical work items planned for the second phase will have to be postponed (probably the artwork item).

Even though I am behind schedule, I am really happy to be moving forward again…

(To my fellow 30-dayers: It has been a while since my last post in the 30-day challenge category - at least if you think of how brief it is. But worse, I am also behind the schedule. My goal was to have the first release candidate on the 15th. It is the 17th and I am not quite there yet. Read on for details)

Every now and then, the Eclipse Project goes through quite significant changes (OSGi and RCP in 3.0, P2 now in 3.4). And when the platform moves this fast, everybody living above feels it. New features are not well documented or are not very stable. Tooling for plug-in developers lags behind. Things that used to work before, are now broken.

That is really hard to avoid, even though backward compatibility with the previous release is a hard requirement for the Eclipse Project. I was part of the Eclipse Platform Core team in 3.0 (shipped in 2004) and even though we were having lots of fun with the move to OSGi and the birth of Equinox, it was a lot of work having to implement the new functionality and at the same time make sure all the existing use cases continued to work. And, as usual, some corner cases we missed were only discovered close to the release date, or even right after, when most people will finally migrate from the previous release. Many of the OSGi-aware features were only exposed by the plug-in development tooling in the subsequent releases. And even though we felt like all that backward compatibility effort was draining a lot of our time and energy, users would still get mad at us for introducing regressions, when they didn’t really give a damn about OSGi or RCP.

In hindsight, it is clear that all that work paid off when you look at the impact that OSGi and RCP had in the growth of Eclipse way beyond the realm of IDE frameworks. People are using Eclipse as a platform for embedded and server-side applications, or rich client applications you could swear were native. OSGi itself had a boom in adoption (and features) since when it was adopted in Eclipse and moved from niche technology into the mainstream.

I am sure the same is going to happen with P2, probably in smaller proportions (given its scope). We will be taking its features for granted two years from now, and the pain of change will have been long forgotten. And the good people developing P2 know that. But, this time around I am…

…on the other side of the fence

The plan of shipping TextUML Toolkit 1.0 (scheduled for June 30th) on top of Eclipse 3.4 (scheduled for late June - yes, that should have raised a flag) proved to be quite a challenge. I have had minor problems with the latest Eclipse SDK milestones, which I could work around, but more recently I have faced more serious, blocking issues. And even the non-blocking problems and difficulties, which are just time wasters, grow in importance when you are in a tight schedule.

So I stepped back and decided to and develop and ship the TextUML Toolkit 1.0 on Eclipse 3.3, which was last year’s release. It was not an easy decision, as I will be missing many improvements and fixes (some of them to pretty significant issues) made in the UML2 and EMF components, which are the main requirements. But at least I should be able to move forward in a more predictable pace, and be more confident I have a chance of meeting the June 30th deadline, even if quality might suffer. On the bright side, thanks to backward compatibility, the same update site should still work with 3.4, so users using the Update Manager/P2 in Eclipse 3.4 should be able to install the TextUML Toolkit features, and get better performance and stability.

What makes me feel good is that backward compatibility continues to be one of the Eclipse key values (e4 rumors aside), so regressions receive high priority and are fixed as quickly as possible. The least we (end-users and product providers) can do is to diligently report them.

Contrary to my original intention of working this week on code generation and the sample application, I have been doing some improvements in the graphical visualization of UML models in EclipseGraphviz. EclipseGraphviz (a spin-off of the TextUML Toolkit) is an open source component (EPL) that integrates Graphviz into Eclipse, and among other things, can generate UML class diagrams from Eclipse UML2 models on the fly.

After fixing a couple of bugs, I decided to add a preference page to give some level of control over the way the diagrams are laid out. Here is what it looks like:

You can now turn on or off several adornments such as association end names, multiplicities and membership. For example, this diagram was rendered using the options shown above:

Whereas the following one was rendered for the same model while having only the “Create constraints for association navigability” option checked:

As you can see, enabling constraints based on association navigability can significantly alter the diagram layout. One good reason for enabling that option is to avoid diagrams that grow too much horizontally (as Graphviz will put all nodes of the same rank on the same row), but I personally prefer the former layout.

Side note: I considered dropping the graphical visualization feature altogether for 1.0, as I see it as just a nice to have, and am not totally happy with the quality of the diagrams generated by Graphviz. But every bit of feedback I got for the TextUML Toolkit was that the graphical visualization was really nice, so I changed my mind. But unless serious bugs are found in this area, I have no plans of touching the EclipseGraphviz code again until after I complete the 30-day challenge.

Side note #2: I expanded the FAQ to cover the issue of notation choice and the role of EclipseGraphviz in the TextUML Toolkit.

Took a first stab at creating the model for the sample application for the TextUML Toolkit. As I wrote here before, the sample application is derived from Sun’s Java Pet Store application. Take a look at the models, and let me know how the textual notation feels.

It is late and I am tired, so it is very likely I have made at least a few mistakes (well, not syntactic ones, as the tool tells me about those). Of course, when I start working towards generating the code from the models, I am sure any mistakes I made will quickly emerge.

Cheers,

Rafael

M5 is now available. You can download a self-contained product install, or use the Eclipse update mechanism for adding the TextUML Toolkit to your Eclipse SDK (3.3 or 3.4), on Windows, Mac OS X or Linux. Please see instructions on the download page.

This milestone was mostly about bug fixing (including a performance bug), but it also included a minor architectural change: graphical visualization is now optional, and supports different implementations.

This is the list of bug fixes:

As I mentioned before, I joined the 30 day product challenge with the TextUML Toolkit. Of the benefits of being part of the challenge, the ones that most attract me are the sense of being part of something greater, and the motivational power of peer pressure (even if imaginary) and fear of public failure. With that in mind, these are my commitments for the challenge:

Phase 1 - June 1st to June 15th:

Focus on finishing development and examples.

• publish the milestone 5 of the TextUML Toolkit (M5) (done)
• making UML graphical visualization an optional component (done)
• publish an example application
  • model - probably a subset of the Java Pet Store app
  • code generation templates - probably using Acceleo
• should target Eclipse 3.4 (done - M5 can be installed on Eclipse 3.4 or 3.3, but download will continue to bundle 3.3 due to lack of tool support for product creation in the new software update mechanism available in Eclipse 3.4)
• bug fixing (continuously)
• improve documentation (continuously)
• publish Release Candidate 1 on June 15th
• development freeze

Phase 2 - June 16th to June 30th:

Focus on polishing and getting it out of the door.

• major/critical bugs
• minor bugs/polish items
• improve documentation (continuously)
• artwork
  • icons for TextUML source files, new project wizard (outsource)
  • website (images, skins)*
• legal stuff
  • make sure we comply with all licenses for any bundled open source software
  • legal notices using Eclipse branding
  • beef up license (no redistribution, no reverse engineering)
• PR (go easy, this is 1.0) - EPIC, announcement-friendly developer forums
• one active beta-tester
• one early adopter*
• screencasts (this is a biggie)
  • creating a UML model using the TextUML Toolkit
  • generating code using Acceleo
• RC3 on June 29th
• declare 1.0 on Monday June 30th

* marks nice-to-have items

There you go. You, my readers (yes, both of you), can now hold me accountable if I fail to accomplish any of the work items I committed to do above.

To my fellow 30-dayers: good luck to us all. It will be fun!

I decided to join a group of fellow mISVers in the 30-day product challenge. Differently from most of the other entries, which will go from product idea to release in 30 days, the TextUML Toolkit has been in development for quite a while now, so my challenge will be to finally ship the first release of the product.

The challenge starts on June 1st. Watch this space for frequent updates as I make progress towards the elusive version 1.0.

Rafael

Up until now, the TextUML Toolkit tutorial had been the only piece of documentation available on the TextUML notation. Well, not anymore. I just finished writing some reference documentation on the notation on the wiki. Since I was already at it, I also created a few topics on UML 101 with TextUML (also on the wiki), taking the text from some posts I have written on the topic.

Any issues or suggestions for the documentation are most welcome.

Rafael

M4 has been declared. If you got the M4 test build that was announced a week ago, no need to download again, it is the same build. Please see that post for a summary of the changes.

The TextUML tutorial has been updated in order to reflect the changes that happened during M4, the most remarkable one being that starting with M4 there are no built-in packages (such as ‘base’ and ‘base_profile’) any longer, other than those defined in UML2 itself. So if you were using elements defined in those built-in packages, you have now to define the elements yourself. The rationale is that the TextUML Toolkit should not be in the business of providing built-in packages nor rely on anything other than standard UML to do its work.

If you didn’t get the test build, go ahead and download M4. If you want to see a feature in the TextUML Toolkit, now it is the time to ask, as the next milestone will be feature freeze. And if you have tried the Toolkit and decided it is not for you, we would die to know why. Your feedback is greatly appreciated.

TextUML is a textual notation for UML. The TextUML Toolkit is an Eclipse-based IDE-like tool for creating UML models using the TextUML notation.

Other tools follow the same approach. Emfatic (now an EMFT subproject) has been doing the same for EMF Ecore for a long time; the TMF project aims to be for textual modeling what GMF is for graphical modeling, and will be based on GMT’s TCS and xText components.

Still, people are often puzzled when I explain what the TextUML Toolkit is. A common question is: “if I am going to write code (sic), why do I need UML anyway?“.

Dean Wampler from Object Mentor wrote on his blog a while ago a post entitled “Why we write code and don’t just draw diagrams“. It is a short post, but he presents very good points on why a graphical notation is usually not suficient and is bound to be less productive than a textual one when it comes to modeling details. For instance, on the saying “a picture is worth a thousand words“, Dean wrote:

“What that phrase really means is that we get the ‘gist’ or the ‘gestalt’ of a situation when we look at a picture, but nothing expresses the intricate details like text, the 1000 words. Since computers are literal-minded and don’t ‘do gist’, they require those details spelled out explicitly.”

Couldn’t have said it better.

I strongly advise you to read the original post in its entirety, but I will leave you with another pearl from Dean’s post (emphasis is mine):

“I came to this realization a few years ago when I worked for a Well Known Company developing UML-based tools for Java developers. The tool’s UI could have been more efficient, but there was no way to beat the speed of typing text.”

Enough said.

The first (and hopefully only) test build for M4 is now available. This is the first milestone where you can get the TextUML Toolkit via Update Manager. Just point Update Manager to:

http://abstratt.com/textuml/update/

Actually, if you are planning to use Acceleo or UML2Tools, it is the best approach. From an Eclipse SDK 3.3 install, point the Update Manager to the site above and install the TextUML Toolkit along with its prerequisites (EMF and UML2). Once you are done, you can install any compatible tools, such as Acceleo and/or UML2Tools (sites will be automatically configured after you install the Toolkit and its prerequisites). If you are not planning to use Acceleo, you can start from an Eclipse Platform install, or you can just download the TextUML Toolkit from the download page as usual.

Follows a summary of the changes that went into M4, including features (in bold) and bug fixes.

I will be writing on some of those features in following posts.

Rafael

The next VIJUG meeting will follow the Lightning Talks format. Last December, I attended the Eclipse Democamp in Vancouver which had a similar format and it was quite dynamic and fast-paced. I am looking forward to VIJUG’s first meeting using this exciting format.

I plan to do a demo on using Acceleo for generating code from UML models, of course, using the TextUML Toolkit for modeling, which is what the next milestone (M4) is all about.

I will be presenting the TextUML Toolkit at this month’s Vancouver Island Java User Group meeting. If you are in the Victoria area, I hope to see you there. It is free, and there will be pizza and drinks. Oh, and there will be a cool demo of the toolkit, including code generation using Acceleo and a quick demo on model execution just to give a hint of what comes next after the toolkit goes GA.

Many thanks to Manfred, the JUG leader, for organizing the meeting, and to Genologics for sponsoring it!

UPDATE: the meeting was great (slides here), got lots of interesting questions and comments, and many in the audience liked the idea of using a textual notation for UML. A bit harder to get buy-in for the idea of UML as programming language. I guess I will need to show something running to get that across too… ;) 

The latest milestone (M3) of the TextUML Toolkit has been declared today, as promised earlier here. As I said before, the focus for this milestone was stability and performance, so you can expect a much snappier and more solid tool. But it also includes some cool new features:

• you can drop UML2 models created elsewhere into a MDD project and you can use them from your TextUML code as you would with models created using the Toolkit
• you can even decompile a UML2 model and read it using the TextUML syntax with the TextUML Viewer (which takes over as the default editor for *.uml files)
• you can auto-format the current compilation unit with Ctrl-Shift-F
• and last but not least: Linux and Mac OS X (Power PC and Intel) are now supported

The main reason for this focus on performance and robustness is that the tool must be something that people can rely upon and become productive with. From now on, real user demand must drive the addition of any new features and bug fixing efforts. So now it is your turn. Download the TextUML Toolkit and start using it for creating your UML models. It is free! If you like the approach of modeling using a textual notation, I am sure you will enjoy it. And even if you haven’t bought the idea yet, give it a try. I would be more than glad of hearing your suggestions and opinions. And more importantly, will make sure that any problems reported will be promptly addressed.

Looking forward to your comments, either here or by e-mail on the Abstratt forum. Cheers.

Rafael

A TextUML Toolkit M3 test build is now available from the download page. If no serious issues are found in this build, it will be declared the final M3 build later this week.

The focus for this milestone was to improve the performance, memory footprint and stability of the tool, and very good progress was made in those areas. But there are also some brand new features, mostly in the area of integration with existing UML models. You can now safely add existing UML2 UML models (built elsewhere) to the project root and they will become available to the textual notation. Another cool feature in this area is that you can now double-click any existing UML2 UML model and read it using the textual notation (think “UML decompiler”). See below the sample model from Getting Started with UML2 in both textual and graphical notations:

Would you like to take a look? Grab the M3 test build, and give it a try. Please report here any problems and leave your comments. As usual, your feedback is really appreciated.

UPDATE: If the diagrams don’t show and everything else seems to work, you probably need the Visual C++ Redistributable package from Microsoft. This is a limitation that seemed to be recently introduced with the Graphviz support on Windows and the Graphviz team is looking into this issue. Sorry for the inconvenience.

Rafael

One common misconception is that UML is a graphical language and that any tools adopting alternative notations (such as a textual one) are inherently non-compliant. That can’t be farther from the truth. Read on to understand.

The fact is that the UML specification clearly separates abstract syntax (the kinds of elements and how they relate) and semantics (what they mean) from concrete syntax (what they look like), and states that there are two types of compliance:

• abstract syntax compliance
• concrete syntax compliance

Concrete syntax compliance means that users can continue to use a notation they are familiar with across different tools. This is important when UML is used as a communication tool in a team environment. Architects, designers, programmers and even many business analysts speak the same language.

Abstract syntax compliance means that users can move models across different tools, even if they use different notations. This is essential when UML is used as a basis for model-driven development. You might want to use tool A for creating the model, tool B for validating the model, tool C for somehow transforming/enhancing the model and tool D for generating code from it (a common form of MDD tool chain).

The TextUML Toolkit uses a textual notation that strictly exposes the UML semantics, but it is not compliant with the language concrete syntax by any means. On the other hand, the toolkit uses Eclipse UML2’s XMI flavor for persisting models and thus is fully compliant regarding the abstract syntax. That is consistent with the vision for the product: a tool from developers for developers that want to build software in a more sane way: the model-driven way. Developers can create models using a notation they are more productive with. Models can then be used as input for code generation using many of the tools available in the market. If non-developers might frown upon a textual modeling notation, they will always have the option of using their favorite graphical-notation based tools for reading the models. I mean, if their tool of choice is abstract syntax compliant as well.

I just added a brand new FAQ section to the web site. It was long overdue.

Here is the first batch of questions:

1. Can a tool that uses a textual notation be considered UML compliant?
2. What are the differences between TextUML and the real UML?
3. I thought UML was all about raising the level of abstraction. Why should I go back to coding?
4. How much does the TextUML Toolkit cost?
5. Is the TextUML Toolkit open source?
6. What diagrams can I create with the TextUML Toolkit?

Do you have any questions that are not answered in the FAQ or do not agree with or understand an answer? Fire your comments, I am always happy to hear from you.

Andreas Awenius, from Empowertec, was kind enough to devote not only one, but two blog postings on the TextUML Toolkit. While his first post was just a paragraph or two acknowledging the use of a textual notation for UML modeling in the TextUML Toolkit, his second post was a very detailed and balanced analysis on the whether using textual notations is a good idea. Even though the conclusion of his posting is that a graphical notation is superior to a textual one, I still agree with many points Andreas has made in his analysis:

1. the presentation notation and the persistence format are completely unrelated concerns (exactly, see my previous comment on this).
2. diagrams are views for models, focused on a specific aspect, and as such must show only what is needed and omit anything that is not essential. (perfect)
3. there are “multiple ways to manipulate the repository, e.g. the conventional - graphical - way or a textual notation”. (yes!)

These are the very same facts that justify the existence of a tool such as the TextUML Toolkit.

1. since user-oriented notation and persistence format are completely different things, you can please users with the most appropriate syntax for their needs (and that is text for many developers), without affecting interoperability with other tools, as tools interoperate at the level of the persistence format. The TextUML Toolkit achieves that by producing UML2 models as the native object file format.
2. the graphical notation is great for creating views, but it is not that suitable for exposing all the details in a model. A textual notation has no problem doing that. The graphical notation is still useful, and this is why TextUML Toolkit will include a read-only graphical view for browsing the repository. And here is the first point I disagree with Andreas. He says: “a diagram must carefully be crafted manually, leaving out all irrelevant detail”. I say: automatically generated diagrams can still obey a set of preferences defined by the user (level of detail, color, font, etc). UMLGraph has been doing this for a long time (albeit by breaking some basic rules of separation of concerns, but I digress). The TextUML Toolkit will embed an upcoming version of UMLGraph in its next milestone.
3. this is basically a conundrum of points #1 and #2. The model created will be the same (from the point of view of tools) regardless the user-facing notation. If users say they would rather use a textual notation, why forcing them to use a graphical one when there are no technical reasons to do so? Here is where Andreas makes several points to back his opinion based on technical and strategical reasons, most of which I (strongly to moderately) disagree. Instead of trying to refute each of those arguments (that is not how you encourage people to provide elaborate feedback), I will use them as an opportunity for driving awareness efforts around the Toolkit, the notation and our future offerings in upcoming posts to this blog.

The ‘raison d’être‘ for this blog is to establish connections with the modeling community at large, users and tool providers. I really appreciate the time and energy that Andreas committed to sharing his views on the TextUML Toolkit and the textual notation approach and am both grateful and honored for that. Thanks a lot, Andreas. Stay in touch. I hope at some point I can convince you that you are wrong!

Last Thursday happened the 1st Eclipse DemoCamp in Vancouver. It was a very dynamic event, with nine short talks packed into little more than one and a half hours. Attendance was high, I was really amazed to see such a great turnaround. The audience saw a diverse range of interesting Eclipse-based projects being developed in Vancouver/Victoria.

I demoed the TextUML Toolkit and got good feedback and some very interesting questions. The idea of a using a textual notation for creating UML models is still not a very easy sell, and that continues to surprise me. Being a developer, I find working with a textual notation so much more natural than a graphical one that it makes it hard for me to see things from other people’s shoes. I plan to go over the issue of textual versus graphical notations on a future post.

All in all, it was a great event. Many thanks to Tasktop’s Robert Elves and Mik Kersten for organizing it, to the Eclipse Foundation for sponsoring the event, and congrats to all presenters.

One weird thing about UML is that there aren’t collection types or array types. Basically, multiplicity and typing are totally independent concerns, represented by the metaclasses TypedElement and MultiplicityElement.

A typed element is a named element that has a type, and that is all about it. Examples of typed elements are value specifications, properties, parameters, pins and variables.

A multiplicity element, on the other hand, is an element that when instantiated potentially admits a collection of values. An optionally defined lower bound value (defaults to 1) can determine the minimum number of instances expected. Whether multiple values are in fact admitted will depend on the upper bound of the multiplicity element, which defaults to 1 (no multiple values allowed), but can be set to any positive integer, or infinity. A multiplicity element that can actually be multivalued can also be characterized regarding ordering (whether values can be accessed by position) and uniqueness (whether values can be repeated).

Some kinds of elements are both typed and support multiplicity (such as properties, parameters, pins and variables), however a few are one or the other (let’s ignore those in this discussion).

Mapping UML to Java

To try to illustrate all that was said above, let’s see a few examples of Java variable declarations and the equivalent declaration in UML (using TextUML syntax):

There are few interesting differences though:

1. in UML, it is the typed element itself that defines multiplicity, and not the type
2. c:Client, c:Client[1] and c:Client[1,1] are all equivalent
3. c:Client[*], c:Client[1,*] are equivalent
4. if a value is optional, the lower bound must be specified to be 0 (example: c:Client[0,1]). There is no Java equivalent for that.
5. unique and unordered are the default in UML (you can use the modifiers ‘nonunique’ and ‘ordered’ to override the defaults)

There are some implications related to assignment when the source and destination are multiplicity elements:

1. the upper bound of the destination must be the same or greater than the upper bound of the source, or a type mismatch will ensue
2. what happens if source and destination differ on ordering or unicity? The UML spec does not sem to cover that (let me know if you think otherwise). In TextUML, any required transformations are performed automatically behind the scenes. For example: if the source is non-unique and the destination is unique, duplicates will be silently suppressed, or if the source is unordered and the destination is ordered, an arbitrary order will be defined.

Well, that was it for today. If you have questions, suggestions or think I got something wrong here, feel free to add a comment.

One of the least known and understood concepts of UML is templates. Section 17.5 on version 2.1.1 of the UML specification covers the Templates package in 31 pages. What follows is an attempt at providing a summary of the mechanism in a way that is easy to understand without actually omitting any important details.

A simple example

The following example in TextUML should be easy to understand for any developer familiar with C++ parametrized types or Java generics:

class Foo
end;

class Bar<T>
    attribute prop1 : T;
    operation op11(par1 : T);
end;

class Fred
    attribute attr1 : Bar<Foo>;
end;

Class ‘Bar’ is a template class, whose template signature contains a single parameter: ‘T’. The type of the property ‘prop1′ is defined as the template parameter ‘T’. Class ‘Fred’ declares ’someOp1′, an operation that takes a parameter whose type is a binding of the template class ‘Bar’. ‘Bar’’s template parameter ‘T’ is bound to the class ‘Foo’. Implicitly, the type of ‘Fred.attr1′ when expanded against Foo should look something like:

class BarOfFoo
    attribute prop1 : Foo;
    operation op11(par1 : Foo);
end;

Note that the expanded class has actually no name, but I am calling it ‘BarOfZoo’ for pedagogical reasons.

Looking closer at the abstractions

• TemplateableElements - abstract super-class for elements that can be declared as templates, or that can bind other templates to a set of parameters. Four kinds of elements can be declared as templates in UML 2.*: Classifier, Operation, Package and StringExpression, and thus only those metaclasses specialize TemplateableElement*.
• ParameterableElements - abstract class that is specialized by any type of element that can be used as parameters to templates.
• TemplateSignature - a template signature is owned by a template element and contains the set of parameters declared by a template element.
• TemplateBinding - a template binding represents the “instantiation” of a template in the form of a directed relationship between a template signature and a a bound element, another templateable element. In addition to tying the template to the bound element through the template’s signature, the template binding contains a set of template parameter substitutions. Which takes us to the next abstraction…
• TemplateParameterSubstitution - a template parameter substitution is created for every template parameter declared by a template signature. It binds an open parameter to an actual parameter, which is a ParameterableElement.

Would you like to play with templates in UML? For now, you will have to look elsewhere. There is some support for templates in the TextUML Toolkit 1.0 M2, but it is, to put it mildly, half-baked. Full template support is planned for M3 (whenever it happens), and that is exactly what I am working right now. I know I am close to getting it right, but assignment compatibility involving template/bound classifiers get be really tricky to implement. Well, whenever I am done, you will learn it first here.
*in the Eclipse UML2 API, Property also specializes TemplateableElement. That seems to be a deviation from the spec, and a bug report has been submited.

A user has just reported that the TextUML Toolkit M2 build did not work at all for him. Ouch. Thankfully, the user included in the bug report all the information I needed to allow a quick diagnostic: turns out he was using a Java 5 VM, and he was getting exceptions like this:

java.lang.UnsupportedClassVersionError: Bad version number in .class file

 at java.lang.ClassLoader.defineClass1(Native Method)

 ...

I then realized that for the M2 build some of the plug-ins were accidentally compiled having Java 6 as the target platform, and thus wouldn’t work on a Java 5 VM. This is being fixed as I write this, and a new M2a build will be available shortly.

So, for those of you running with a Java 5 VM, please make sure you download the TextUML Toolkit M2a build. Otherwise, if you are using a Java 6 VM, you should be fine with M2, no need to download the build again.

Thanks to Jon for reporting the issue. Keep those bug reports coming!

Profiles and stereotypes form a lightweight mechanism for extending the UML metamodel.

A stereotype allows you to tag elements in your model so they can be interpreted differently from ordinary model elements, much like annotations work in languages such as C# and Java. These tags can then be used to drive code generation, for example, so for every class marked as “persistent”, appropriate persistence code should be generated.

A profile is a special kind of package intended to contain stereotype declarations that extend UML to cover some specific domain or platform.

Let’s see how to declare and use profiles and stereotypes with the help of the TextUML Toolkit.

Declaring a stereotype

To declare a stereotype in TextUML, one uses the following syntax:

profile <profile-name>;

stereotype <stereotype-name> extends <metaclass-1 [,...metaclass-n]…]
[<property-1>; [... property-n;]…]
end;

end.

In other words, a stereotype can be declared as applicable to one or more metaclasses (i.e. types of elements in a UML model), and a stereotype can optionally declare properties (more on properties later) . For instance, a classes could be tagged with the <<persistent>> stereotype:

profile business_apps;

import uml;

stereotype persistent extends Class
end;

end.

Or operations could be marked as <<transactional>>, meaning that a transaction will be started whenever the operation starts executing, and finished when its execution ends:

profile business_apps;

import uml;

stereotype transactional extends Operation
end;

end.

Any UML element can be affected by stereotypes, but stereotypes are declared as targetting (potentially multiple) specific element types. For instance, the UML specification has an example of a profile for Enterprise JavaBeans that defines a <<Session>> stereotype for session beans. The<<Session>> stereotype declares a property that allows modelers to define whether the session bean component is stateful or stateless.

profile EJB;

enumeration StateKind
  STATELESS, STATEFUL
end;

stereotype Bean extends uml::Component
end;

stereotype Session specializes Bean
  property kind : StateKind;
end;

stereotype Entity specializes Bean
end;

end.

Applying a stereotype

Now that we know how to declare stereotypes, lets see how to use them. First of all, you must apply the profile defining the stereotypes to the model declaring elements you want to apply stereotypes to:

model bank;

apply business_apps;

/* other model elements here */

end.

You can then attach stereotypes defined in the applied profile to the suitable model elements in your model:

model bank;

apply business_apps;

[persistent]
class Account
    attribute accountNumber : base::String;
    attribute balance : base::Real;
    attribute changes : AccountChange[0,*];
    [transactional] operation withdraw(amount : Real);
    [transactional] operation deposit(amount : Real);
    operation balance() : Real;
    [transactional] operation transfer(other : Account, amount : Real);
end;

end.

In the example above, we applied the <<persistent>> stereotype to the Bank class, and the <<transactional>> stereotype to the withdraw, deposit and transfer operations. In order to have access to these stereotypes, we had to apply the “business_apps” profile to our model.

Conclusion

In this post/article on UML basics using TextUML, we saw how to declare stereotypes and apply them to elements in UML models. We learned that a stereotype must explicitly declare the metaclasses they are applicable to, and that optionally stereotypes might declare properties. Finally, we saw that before a stereotype can be used in a model, the profile declaring the stereotype must be applied to the model.

After a few minor bug fixes and improvements to the test build, the M2 milestone of TextUML Toolkit is available. With this milestone you can:

• create UML models using the TextUML textual representation
• visualize the model created using the conventional graphical notation for class diagrams

This milestone does not support non-Windows platforms. But progress is being made in that direction. See below a screenshot of TextUML Toolkit running on Ubuntu Feisty Fawn:

Just go to the download page and fetch it, it is free with no restrictions (or guarantees). Make sure to check out the tutorial. Your feedback is most appreciated.

Now off to a long weekend on the beach…

A TextUML Toolkit 1.0 M2 test build is available off the download page. If no serious issues are found in this build, it will be declared the final M2 build later this week.

The key feature developed for this milestone is the graphical class diagram viewer, which reuses the EclipseGraphviz project. The viewer shows a live representation of the UML model built from your TextUML source file using the standard graphical notation. It can also be used to visualize UML files created by any UML2 compliant tools.

Other significant change is that the “extends” keyword is now used specifically to state the metaclass a stereotype is a applicable to, whereas “specializes” should be used for class inheritance. This was for a better alignment with the official UML terminology. Finally, there is now support for declaring enumerations.

Would you like to take a look? Grab the M2 test build, and give it a try. Your feedback is much appreciated.

RC

In the context of providing class diagram visualization for TextUML Toolkit, I have developed a simple graphical viewing framework for Eclipse. It is content type based, and allows you to view anything a content provider has been registered for. For instance, any image file supported by SWT:

But you can also view the graphical representation of a Graphviz DOT file, and it will even update as you edit the file:

And finally, and also the reason why I had to develop support for DOT visualization in the first place, you can also visualize a UML model (here showing a model created using the TextUML Toolkit):

All these features (except for the TextUML Toolkit itself) are part of the EclipseGraphviz project, which is open source (EPL). No releases yet as this is still very new, but you can grab the source from the Subversion repository. If you would like to contribute to the EclipseGraphviz project, or to the graphical viewing framework, your help will be most welcome.

RC

Just finished a raw implementation of a viewer for GraphViz dot files. Here is a screenshot:

By the way, the project has been provisioned on SourceForge with the suggestive name of EclipseGraphviz.

RC

Would you like an Eclipse-based development environment for composing Graphviz diagrams, for instance, an editor with syntax highlighting, on-the-fly validation and visualization? Or would you, as an Eclipse plug-in developer, like an easy way of producing nice looking diagrams by calling Graphviz from your own Eclipse application?

Well, we have the second need (for our TextUML Toolkit product) and I have started developing it as an open source project to be maintained on SourceForge (project being provisioned as I write this). We will certainly need help from other contributors. Help will be mostly welcome with the end-user oriented features as our initial focus will be on producing an API for invoking Graphviz from within Eclipse.

(By the way, it has been a while since the last post. Meanwhile, I have been busy moving back from Brazil to Canada (more specifically to the beautiful Victoria, BC), finding a new home and buying a new computer. The trip itself was exhausting (5 flights across a week), but it could have been much worse had I followed Google’s advice.

From now on, you should see a new post here at least once a week. The plan is to have the second milestone for TextUML Toolkit (with diagram visualization) in about two weeks. Stay tuned.)

UML has become the lingua franca for modeling applications using the object-oriented paradigm. People use UML in many different ways (see the post on UML modes), ranging from as a communication tool to as a full fledged programming language that supports full code generation. This last way of using UML should puzzle most readers - how can UML models lead to full code generation?

UML has two diagrams that are used for behavior specification: the activity diagram and the state diagram. These two diagrams (more one than the other, depending on the nature of the subsystem being modeled), plus the class diagram (for modeling the structural aspects of the object model) provide the framework that supports the design of complex applications in a way that is fully complete (and thus allowing 100% code generation) while still implementation independent (see earlier post on platform independence). All the other diagrams (use case, sequence, collaboration) are interesting for gathering requirements, but are useless in modeling a solution that can be automatically transformed into a running application, and thus we will ignore them here.

Specifying structure with the Class Diagram

The class diagram is the most well understood of all diagrams in UML. You can model all structural aspects of your object model in the form of classes, attributes, operations and relationships between classes. This specification of structural aspects can then be used for generating (boilerplate) code, database schema, configuration files and so on so forth. This is great already, as that is most of the work. But without including behavioral aspects, it is impossible to do full code generation solely from the class diagram, you are forced to fill the empty methods with handwritten code (unfortunately this is how most vendors expect you to do model-driven development). Still, the class diagram is a fundamental one in which it provides a base framework the other diagrams can build upon.

Specifying dynamics with the State Diagram

The UML state diagram (derived from David Harel’s state charts) allows for a full design of the dynamic aspects of a system. One can model complex state machines using the state diagram, always in the context of a class described in the class diagram. Many mainstream applications do not have any interesting dynamics though, so in those cases the state diagram has limited value. However, in applications for certain industries (such as robotics, telecom and automotive) it is the most important diagram.

Specifying business logic with the Activity Diagram

The most underrated of the UML diagrams, the activity diagram has a key role: it is the only one to allow the modeler to specify behavior in a precise way. The Activity Diagram provides elements (such as actions, pins, data and control flows, signals) that allow specifying the meaning of a behavioral element (such as the body of an operation from the class diagram, or the effect of a state transition from the state diagram).

But no matter how important the UML activity diagram is, it has one strong limitation: it demands too much detailed information in order to be fully defined (and thus actually useful in the context of code generation). Any simple logic that could be written in a few lines in, say, Java, requires a graph with so many nodes that it is virtually impractical to use it with the graphical notation, severely hampering its more widespread adoption.

Have I just suggested that activity diagrams are useless for any serious usage? No! It is just the case that the graphical notation is too cumbersome, and it is not just a problem with the specific choice of symbols - there will never be any graphical representation that can be as expressive and concise for specifying behavior as your programming language of choice (even if your favorite language is as verbose as COBOL). So it is a matter of representation: a textual notation is much more appropriate than a graphical one. The activity diagram itself is fine, thanks.

So what is the textual notation for the activity diagram? There is none. I mean, not one defined by the OMG. Many companies have defined their own action languages (such as Pathfinder AL, Bridgepoint OAL, Kennedy Carter’s ASL) with compilers that provide a textual front-end for the UML activity diagram. TextUML itself has a bigger cousin (currently an ongoing work) that allows specifying UML activities in a way that is familiar to any programmer. Want to see what an action language looks like? Expect a new post on the subject (including our very own action language) here soon.

On his bliki, Martin Fowler eloquently describes the three different modes in which UML can be used: UML as sketch, UML as blueprint and UML as programming language. Let’s revisit the different modes from the perspective of tools for the job.

UML as sketch

Description: In this mode, UML is essentially a tool for conceiving and communicating ideas between team members. As such, there is no need for completeness or validity of the object models, and actually any information not essential for communicating the idea at hand is intentionally omitted for conciseness and clarity. UML as sketch is increasingly popular, even at shops where model-driven development is considered an abomination.

Tools for the job: developers don’t need special tools for using UML as a sketching tool, paper and pen or a whiteboard are great. The only flaws are when you would like to archive a drawing or send it to others by email. In that case, Visio (or any other generic diagram editor) is a common choice. Another less known option is Whiteboard Photo, that allows you to take a snapshot of your hand drawings (on a whiteboard or on paper) and have them automatically translated into great looking clean 2-D charts.

UML as blueprint

Description: in this mode, the focus is on having UML models used as an input to the implementation phase, and thus need to be valid and complete from the point of view of structure. Behavioral aspects are described in textual form (such as in use case descriptions) or by means of diagrams depicting scenarios (such as sequence or collaboration diagrams) and are inherently informally and incompletely described. The models can be submitted as input to code generation but the generated code has to be enhanced by hand to cover the behavioral aspects.

Tools for the job: generic tools won’t cut it here - you will need diagram editing tools that support all (or most) of UML diagrams, and (if you are taking the code generation route) persist your models in a format that your code generation tools can understand. Most UML tools out there support (or intend to support) this.

The TextUML Toolkit we provide supports this mode too. Your class diagrams are fully verified, and are persisted using a standard format.

UML as programming language

Description: In this mode, UML models must be complete both structurally and behaviorally as they must be simulatable and serve as input to code generation (by the way, Fowler really misses the point when he argues that a graphical language such as UML is not appropriate for fine grained behavior specification - who said UML is graphical anyway?).

Tools for the job: there are only a few tools currently in the market that support this mode, they tend to target embedded software development, and I bet you will not find how much they cost on their websites unless you call them.

Corcova Libra will support this, and when made available will visibly sport a reasonably fair price on our web site. Also, Libra will aim at mainstream business application developers, instead of focusing on specific vertical markets.

Conclusion

UML as sketch is cool and useful, but from the point of view of software engineering (our focus here) is meaningless.

UML as blueprint is increasingly practiced in shops where (partial) code generation has been adopted. It has benefits over writing the entire code by hand, but it still requires all the interesting code to be written manually, and there are a lot of issues with that.

Finally, UML as programming language (in other words, full blown model-driven development) is the most interesting of the three modes, even if there is a lot of skepticism and misinformation towards it. I will talk about that in an upcoming post.

RC

Even though a textual notation such as TextUML is much more productive when creating UML models, the graphical notation is still better for a high-level overview. So, for the next milestone of the TextUML Toolkit, the main feature planned is a model visualizer using the conventional graphical notation of UML.

The first option considered in implementing that feature was the UML2 Tools project, part of the Eclipse.org Model Development Tools project. UML2 Tools supports viewing and editing most of UML diagram types, and works seamlessly with models created using UML2 and EMF, which the TextUML Toolkit already uses, and that is great. However, it also requires GEF and GMF, what is bad because it significantly increases the download size for the TextUML Tookit (currently at 31MB), already high for the value it currently provides. Also, from some initial experimentation, it seems to be very computation and/or memory intensive. Because of that, it was decided a more lightweight alternative should be found, even more so if you consider interactivity and support for diagrams other than the class diagram are very low on our list.

Enter Graphviz and UMLGraph

Graphviz is an awesome tool for graph visualization. Graphviz takes simple text files (in the dot notation) describing the graph structure and produces great looking diagrams.

However, Graphviz is very generic, and does not know anything about the UML notation. That is when UMLGraph comes into play. UMLGraph produces dot files that generate OMG compliant UML diagrams (like the ones showing here).

So the direction is to adopt Graphviz and UMLGraph into a lightweight, non-interactive graphical viewer for UML class diagrams. We don’t dismiss having a more powerful graphical viewer (and editor) in the future, probably based on the UML2 Tools project, but the focus now is on simplicity.

There are two difficulties into adopting Graphviz and UMLGraph though:

1. Graphviz is a native standalone tool, not a Java API
2. UMLGraph, as a Java doclet, supports only one input representation: Java source with Javadoc comments

Turns out the first obstacle can be easily overcome by wrapping the Graphviz binaries into platform-specific fragments and providing a simple Java API on top of it.

The second obstacle is a bit trickier though. UMLGraph ties the usage of the doclet API into the generation of output in dot form. Breaking that coupling requires a non-trivial refactoring effort. I have been talking to UMLGraph author Diomidis Spinellis and he is keen on the decoupling, and that is the route we are going to take.

Would you like to see what it looks like? Make sure to check out the M2 milestone coming out in mid-June.

RC

It has been suggested that it is often the case that non-Java developers are not familiar with Eclipse-based products. Thus, we have made available to Windows users a single-click download option containing only the essential plug-ins from the basic Eclipse platform, EMF and UML2, plus the TextUML Toolkit itself. Check out the download page.

Users will still have to make sure they have Java 5 or later installed. The ZIP file has 31MB, so if you are familiar with Eclipse, we appreciate if you get the platform, EMF and UML2 from Eclipse.org to keep our hosting costs under control.

Thanks for the feedback, and keep the suggestions coming!

 RC

There hasn’t been a post here for a while, but there is a good reason for that: we are glad to announce that we now have an actual web site (go see for yourself) and have simultaneously made the first public release! TextUML Toolkit 1.0 M1 is the first milestone of the tool we have developed for creating UML models in a way that is more natural to hard-core developers. If you want to know more, go read the overview, download the tool and try out the tutorial.

After a long period of silence, I almost pity that I have somehow crammed too many great news on a single post…

RC

Thanks for checking us out. We are busy working hard on a tool that will bring software development productivity to a whole new level. At some point this summer, we will release a full fledged model-driven development tool, with support for model execution and complete code generation.

Before that, as a preview, we plan to release one of its components as a standalone product. It is a UML authoring tool that presents a hybrid textual/graphical notation. Our hunch is that even hardcore hackers will want to use it.

Stay tuned!