Traceability between an EMF Java model and the corresponding source code

MoDisco 0.9M4 has been released this week with Eclipse Indigo M4.

One of the new interesting features is the traceability between an EMF model created from the reverse-engineering of a Java application and the corresponding source code.

It allows to directly navigate from elements of the Java model in the MoDisco Model Browser to the corresponding code fragment in a Java editor.

This feature is provided by a new Java discoverer which can be executed with the MoDisco menu "Discover Java and Inventory model from Java source code" available on a Java project.

This discoverer automatically creates three EMF models:

• a Java model describing the content of the source code: it is the model created by the basic Java discoverer.
• a KDM Inventory model describing the structure of the Java project (all the files and folders).
• a traceability model containing relations between the Java model elements and source code fragments

If you need to know more about these models, you can read the documentation of the discoverer.

When you launch the discoverer on a java project, the traceability model is automatically opened in the MoDisco model browser. 

To activate the synchronization with the Java source code editor, you need to activate the "Synchronize with source code option". 

Now, when you click on a model element in the model browser, the corresponding source code is automatically highlighted in the Java source code editor (otherwise, the double-click on an element opens the property view).

Spy On Your Models - Part 4

In this sequence of posts, I explain how to use the Model Browser provided by MoDisco to inspect an EMF model.

In the first three posts, I have described how to directly access to instances of a given type, how to navigate through the model elements and how to customize the browser.

In this last post, I will now describe how to create and execute queries on model elements directly from the browser.

The features presented in the previous posts, allow you to navigate through the elements of your model by traversing the links. You can also highlight some characteristics of specific elements by defining a customization which dynamically change their rendering (icon, label, font, color, etc).

But in some situations, you would like to calculate values from model elements. These values could be of basic types (numbers or strings) or could be other model elements.

MoDisco provides a mechanism to execute queries interactively on model elements selected in the Model Browser. First, I will explain how to execute queries, and we will see later in this post how to declare and implement them.

There are two possibilities to execute a query.

The first one consists in selecting model elements in the browser and clicking on the menu "Execute Query ...". It opens the "Query Execution" view which contains two main parts:

• The elements on which to execute the query. It is filled with the elements you have selected, but you can also remove elements from this list or drag&drop new elements  from the browser.
• The registered queries which can be executed on the selected elements

When you click on "Execute" the selected query is executed on each model element and the result is displayed in a table (more possibilities will be provided with future versions).

The table displays each returned value on a line. If the result is a basic type, the table contains only one column. But if the result is a model element, the table contains several columns:

• A colum "Label" which contains the calculated label of the object.
• A column "Metaclass" which contains the type of the object
• A column "/eContainer" which contains the parent of the object
• A column "Query Context" which contains the object for which the query has returned the object
• A column for each attribute of the corresponding metaclass
• A column for each reference of the corresponding metaclass (for nary references, the tablel displays the number of related objects).

On each line, it is possible to re-execute a query or to browse the selected element with the model browser.

To execute a query from the browser, the second possibility consists in adding the query to a model element in the browser by clicking on the menu "Dispaly Queries on Selected Element":

A dialog is opened with all the applicable queries:

The selected query is added to the model element. When you click on this query, it is executed and the result is displayed under the query:

Now, to create your own query, the first step consists in creating a QuerySet in a MoDisco project: right-click on the project, select the menu "New>Other" and select "MoDisco / QuerySet model":

Give a name to your new QuerySet and MoDisco creates it in the project:

A QuerySet is a model which contains the declaration of the queries. The new QuerySet is empty. So, to start declaring the queries, just double-click on the QuerySet to open it with the dedicated editor:

Now, you need to associate the QuerySet to a metamodel: all the queries will apply on model elements of the corresponding models. 

Let's say we want to declare queries for UML model elements. This association is done in two steps: 

• Load the ECore definition of the metamodel: right click on the ModelQuerySet instance, select the menu "Load meta-model ressource" and select the right ECore definition.

• Associate this metamodel to the QuerySet: double-click on the ModelQuerySet instance to open its property view, click on the button in the "Associated Metamodels" property field, and select the metamodel.

Now, you can start declaring the queries: right-click on the ModelQuerySet instance and click on the "New Child" menu. You can declare queries of three kinds: Java, OCL or XPath.

For each query, you have to declare its name, its scope (on which elements the query is applicable), its return type and its multiplicity (lower and upper bounds). Implementing the body of the query depends on the kind of query:

• OCL: enter an OCL expression in the "Query" property
• XPath: enter an XPath expression in the "Query" property
• Java: enter the name of a Java class which implements the query

To know more about how to declare a Query, you can read the reference documentation of the MoDisco QueryManager.

An Eclipse Modeling Week

Last week, I participated to Eclipse Summit Europe 2010 in Germany.

I started tuesday with a talk at the Eclipse Modeling Symposium (you can read my previous post: Using EMF to represent Eclipse 3.x plug-ins , and a complete summary of the symposium on Ed Merks' blog).

Then thursday, with Grégoire Dupé, I presented EMF Facet, the new Eclipse/Modeling project we have created to allow dynamic extensions of existing EMF models.

EMF Facet at ESE 2010

We have finished the week friday, at Eclipse Day Paris, by a presentation of MoDisco, the Eclipse/Modeling project dedicated to Model-Driven Software Modernization.

MoDisco at Eclipse Day Paris 2010

Now, we can come back to a normal activity ... until MD Day 2010, the 25th of November in Paris.

Spy On Your Models - Part 3

In this sequence of posts, I explain how to use the Model Browser provided by MoDisco to inspect an EMF model.


In the first two posts, I have described how to directly access to instances of a given type, and how to navigate through the model elements. In this third post, I will now describe how to customize the browser.



When your model contains a large number of model elements, you need help to identify the nature of the objects your are looking for. A good idea is to define a graphical extension to associate a specific graphical rendering (icon, label, color, etc). It can be achieved with the EMF.Edit framework by developing content and label provider classes. You can develop and deploy a new plug-in, and once this plug-in is installed, the customization is applied systematically. 


But in some situations, you need a more flexible customization. A customization which presents the model according to a given viewpoint. A customizations that you apply temporarily, depending on a working situation. 
This is what you can do by creating a UICustom model. 


A UICustom model defines graphical properties for elements of a metamodel (a ECore model). These properties can be loaded dynamically by the Model Browser and applied to the model elements.
First, you have to create a new MoDisco project:

Then, create a UICustom model in this project:

The UICustom creation wizard asks which is the metamodel to be customized. It proposes all the ECore models registered in your Eclipse:

Once created, you can edit the UICustom model with the editor provided by MoDisco:

Now you can select a metaclass and edit its graphical properties (label, bold, italic, font, color, icon, visible, etc). You can also customize the attributes and the references of the metaclass.


Each graphical property can be set with a static value (for example, define a new icon for all the instances of Class) or a dynamic value, computed by a Query (for example, the label of an instance of Class can be italic if its "isAbstract" value is true).


To understand how to define a customization, you can read the user manual in the MoDisco wiki.


Once saved, a UICustom is applicable. Click on the "Load Customization" button in the toolbar :

Your UICustom model appears with all the other registered UICustom models. You can select it to apply it on the current model loaded in the Model Browser.

In the next post, I will describe how to create and execute queries on model elements directly from the Model Browser.

Spy On Your Models - Part 2

In this sequence of posts, I explain how to use the Model Browser provided by MoDisco to inspect an EMF model.

In the first post, I have described the Types panel which allows to directly access to all the EMF instances of a given EClass. In this second post, I will now describe the Instances panel which allows to inspect an EMF object and navigate to all the other connected EMF objects.

This panel is a tree containing all the instances of the type selected in the Type panel. If you open a model element, you can see all its properties: the attributes and the references declared by the type (the metaclass) in the corresponding ECore model (the metamodel).

The attributes are displayed with a green bullet and the value of the selected instance. The references are displayed with an icon inspired by UML associations: containment references have a diamond (like UML compositions), references with no opposite are terminated by an arrow (like UML navigable roles). Derived properties are prefixed by "/".

On each reference, you can right-click and select the "Add child" menu to add new EMF objects.

If you want to hide empty and derived references, unselect the buttons "Show Empty Links" and "Show Derived Links". Then the tree will only display setable references which have at least one connected object.

When you open a reference, you can see all the objects connected through this reference. This is very helpful to know how the objects are connected to each other. Especially when the current type declares several references of the same type: in this case, you see precisely the connected objects under each reference.

This instance tree proposes several other interesting options.

Let's see some of these options:

• Show Multiplicity: This option displays the upper and lower bounds (between square brackets) of each structural feature as they are defined in the corresponding ECore model.

• Show Ordering: This option displays the index (between square brackets) of each element under a reference which has the "ordered" ECore property set to true. It is useful if you have already selected the "Sort instances" option which displays the elements in an alphabetical order. See below the instances of Property sorted by name under the ownedAttribute reference: they are suffixed by the index within the list of attributes of the current class.

• Show Opposite Links: this option indicates the name of the opposite links (if there is one defined in the ECore model). This option helps to know which reference allows to go back to a given object. Below, you can see that the owner reference can be used to go from an instance of Comment back to the class CollectInformation.

• Show Container: When there is no opposite link defined, this option helps you to go back to the container (the objects which holds the current object with a "containment" reference). The eContainer reference is part of the EMF framework.

• Show Types of Links: This option indicates the Type declared for each reference. It is useful to know what kind of objects you can find under a reference. Below, you can see that the packagedElement reference accepts instances of PackageableElement. It explains why you find instances of Class and Association which both inherit from PackageableElement.

In the next post, I will explain how this browser can be dynamically extended and customized.

Spy On Your Models - Part 1

Have you ever been stuck with an EMF model, trying to find what was going wrong? Which relation is broken or missing ? Where is that model element which should be there, related to that other one ? How many instances this EClass has in the model ?

Of course, you can use the EMF reflexive editor. It is suitable for small models, but when your model contains a lot of model elements it is hard to find your way (you must start from the roots elements, you don't see the name of the relations between the objects, the tree doesn't show the objects pointed by non-containment relations, etc).

So, if you really need this kind of information (and if you are not an expert in reading XMI files in plain text), the model browser provided by MoDisco is a solution for you.

To allow inspecting the details of large and complex EMF models, MoDisco (the Eclipse/modeling project dedicated to Software Modernization) provides an editor with lots of interesting features.

After MoDisco installation, you can right-click on any EMF resource and open the browser by selecting the menu "Open with > MoDisco Browser".

In this suite of posts, I will describe the main features of this tool.

The first feature is a panel, on the left-side of the browser, displaying the classes (metaclasses) of the corresponding ECore definition (the metamodel). The selection of a type displays all its instances in the right-side panel. Each type is suffixed by the number of its instances. By default, only the types with at least one instance are listed, but if you click on the "(0)" button, the empty metaclasses are also listed.

Sometimes, it can be helpful to see also the instances of the subtypes too. For example, in a UML model, if you consider the DataType metaclass you may need to access also to the Enumeration and PrimitiveType instances. It is possible by clicking on the button "Display Instances of Submetaclasses".

By clicking on the button "Show Derivation Tree", you can also display these types in a tree, organized according to the "eSuperTypes" relation.

Four other options are available: to sort the types alphabetically, to sort them by the number of their instances, to group them by package and to show their full qualified name.

Of course, standard features provided by EMF on EClass are still available. For example to get the references to a metaclass, the menu "Show References" opens the view "EClass References".

Another important feature provided by the browser is the management of large models. If a type as more than 1000 instances, they are displayed by groups of 1000 instances.

In a next post, I will describe the features related to the Instances panel which allows to view the properties of each instance and to navigate through its references to other instances.

Using EMF to detect loops within a JSP

After my post explaining how to create EMF models from JSP pages, someone posted a comment on TheServerSide to know if the EMF model could be used to detect loops in the JSP (http://www.theserverside.com/news/thread.tss?thread_id=60980).

In fact, you can integrate loops in a JSP with several ways. The EMF model will represent these ways differently.

If you write a scriptlet containing a loop in Java (for, while, ...):

the EMF model created from this JSP will contain a JSPScriptlet object which contains the text of the scriptlet.

The discoverer currently provided by MoDisco does not parse the content of the scriptlet. It will be provided in a future version (after Indigo) by using the Java metamodel to represent the Java fragments contained in a scriptlet.

Another way for looping in a JSP can be achieved by using the "forEach" tag:

In this case, the EMF model will contain a JSPAction object whith the name of the tag ("c:forEach" here):

This EMF object contains children which are the attributes of the tag (var, items, varStatus, ...) and the sub elements of the tag (a JSPAction "c:choose" and an Element "tr"):

How to create EMF models from JSP pages ?

The next release of MoDisco (version 0.9) is under development and is planned to be released with Indigo. This release will come with new components for creating EMF models from the source code of JEE applications.

The current version (version 0.8) already provides components for creating EMF models from java source code (see this older post). In next version, new components will be dedicated to JSP reverse-engineering. They have been developped by Fabien Giquel and Nicolas Guyomar of Mia-Software.

They are composed of:

• a metamodel for describing a JSP
• a discoverer for creating a model from a set of JSP pages
• a generator for generating JSP pages from a model

The JSP metamodel (defined with Ecore) is an extention of the XML metamodel (also provided by MoDisco) which contains types such as Page, JSPScriptlet, JSPExpression, JSPTagLib, etc.

The discoverer, is a component which analyzes JSP pages and creates an EMF model conforming to the JSP metamodel.

It can be launched from a project, or directly from JSP pages.

The result is an EMF model which can be opened with the MoDisco Model Browser.

The generator allows regenerating JSP files from an EMF model (conforming to the JSP metamodel). While it still needs to be improved to support a better formatting, yet it can already be used to produce JSP files.

With these new components, you can reverse-enginer JSP files and use EMF APIs in order to control coding norms, detect patterns, document existing pages or refactor them by applying transformation at the model level (and then use the generator to get a new version of your JSPs).

Getting feedback from adopters

The OMG Technical meeting at Minneapolis is over, I will come back to Nantes tomorrow.

This kind of event is a very good opportunity to meet users of the tools we have developped for Eclipse. As anybody can download these tools, it is difficult to know precisely how they are used, and by who.

For example, this week I discovered that Nicolas Rouquette from the NASA, was using the MoDisco Model Browser to inspect complex XML documents! This browser has not been developped for this purpose. But, as MoDisco comes with an automatic transformation of XML files into EMF models, you can load any XML file directly into the browser, and benefit from all its navigation, filtering and customization capabilities!

Just click on an XML document, select the menu "Open with > Other..." and pick the "MoDisco Model Browser".

We really appreciate all these kinds of feedback: they are of great help while defining our roadmap :-))

If you have adopted (or are going to adopt) MoDisco , feel free to post your feedback (good or bad, it helps in both cases) on this blog, or on the MoDisco forum .

Helios is out. Now, let's take the Indigo train!

How to install MoDisco with Helios?

This year, for the Helios release, the Modeling Package offers a very simple way to install the Modeling components.

The Modeling Package is one of the Eclipse pre-packaged distributions available from the download page (http://www.eclipse.org/downloads/).

Once you have downloaded and launched this package, just click on the "Install Modeling Components" button from the toolbar.

This button opens a window displaying all the available Helios Modeling components. Select MoDisco and click on the Finish button.

A wizard appears to display all the MoDisco components which will be installed.

Click on Next, then click on the "I accept the terms of the licence agreement" to finish the installation.

Restart Eclipse and it's done! You have now access to the features provided by MoDisco 0.8.

Some of these features are directly available to manipulate or create EMF models, without having to write a line of code:

• Customizable model browser
• Reverse-engineering of Java source code into a Java model
• Reverse-engineering of XML files into XML models
• Reverse-engineering of a structure of a project into a KDM-Source model
• Transformation of KDM-Code models into UML2

In addition, as a platform for Software Modernization projects, MoDisco also provides a lot of components to help you in the development of model-driven reverse-engineering tools.

Enjoy!