This plug-in proposes a small framework for building weaving information between code models (Java, C++, ...) and physical resources (disk files and directories). Such a weaving information is convenient for client programs in order to access physical files.
For example, the MoDisco Model Browser may use this information for displaying original code portions associated to Java model elements.
This plug-in is an infrastructure component and it does not provide features to the MoDisco end-user. Only the contributor and adopter communities are concerned by this plug-in.
This framework reuses the KDM "Source" subpackage, which proposes a model for physical resources, known as "Inventory Model".
The feature is in the scope of a larger issue: the composition of metamodels . Considering that the composition with kdm inventory metamodel is a recurrent composition case, providing a dedicated minimal framework was convenient.
The MoDisco "Java Application" is the reference metamodel and discoverer for illustrating the use of the KDM Source extension.
The component proposes a small framework for building weaving information between code models (Java, C++, ...) and physical resources (disk files and directories).
This framework reuses the KDM "Source" subpackage, which proposes a model for physical resources, known as "Inventory Model" (see figure here)
The KDM inventory model also proposes SourceRegion/SourceRef concepts for weaving other kdm models (kdm code models, ...) with a physical representation. Some references exist from other KDM subpackages to the SourceRef concept.
MoDisco proposes to compose KDM inventory models with non-KDM models. For generic reuse reasons, a new metamodel extending KDM Source has been created.
A subpart of the KDM Source model is extended for linking the SourceRegion concept with non-KDM elements, via the ASTNodeSourceRegion metaclass.
Moreover a recurrent pattern, in such a model composition, is to link a KDM SourceFile with a code model element. Such a link is represented with the CodeUnit2File metaclass.
This is a core metamodel that the developer should extend for describing a composition between a specific code metamodel and kdm.source.
Given a particular code metamodel (such as the Java one), MoDisco proposes to extend KDMSourceExtension to define a metamodel composition between inventory models and code models.
The ASTNodeSourceRegion should be subclassed, and a reference to one concrete code metaclass should "specialize" the ASTNodeSourceRegion->node:EObject reference (one simple way is to set the new reference as derived from the generic one).
(TODO : an opposite reference should be described for allowing navigation from code elements to the SourceRegion instances --> waiting for facet shortcut evolution to come)
In most cases the CodeUnit2File will be subclassed.
A reference example of such a composition metamodel is the Java Application example.
After describing a composition metamodel, the contributor/adopter has to write an associated
discoverer. Such a discoverer will instantiate elements for the
composition metamodel described above (SourceRegion...) Such a discoverer will have to manipulate both the kdm.source model and the code model.
A discoverer for the related code model is a prerequisite. The Java Discoverer is an example. Such a discoverer is not supposed to instantiate SourceRegion subclasses. To avoid ambiguity, we will talk about it as a "leaf code discoverer".
The composite discoverer should, in most cases, invoke the leaf discoverers (kdm.source and code). Another way is to provide the leaf models as parameter values to the composite discoverer.
A kdm.source model can be discovered using the
KDM Source discoverer]. Note that such a discoverer only provides a representation of files/directories. It does not instantiate SourceRegion subclasses.
A reference example of such a composition dicoverer is the
Java Application discoverer example (Java class org.eclipse.modisco.java.composition.discoverer.DiscoverKDMSourceAndJavaModelFromJavaProject).
An abstract java class is proposed to facilitate and factorize some common code: org.eclipse.modisco.kdm.source.extension.discovery.AbstractComposedKDMSourceDiscoverer2.
This abstract discoverer proposes a process with four steps:
Using the AbstractComposedKDMSourceDiscoverer2 is not mandatory.
In most cases, code discoverers have access to the physical location of each portion of code that is modeled.
There are two ways for a composite discoverer to retrieve such information when invoking the leaf discoverer :
The second way implies the leaf discoverer to implement the org.eclipse.modisco.kdm.source.extension.discovery.ISourceRegionNotifier class to support the registering of org.eclipse.modisco.kdm.source.extension.discovery.SourceVisitListener.
ISourceRegionNotifier#notifySourceRegionVisited must be called when appropriate from inside the leaf discoverer.
You may subclass the proposed abstract class ISourceRegionNotifier which already implements ISourceRegionNotifier, and inherits from AbstractModelDiscoverer.
The Java discoverer implementation class illustrates the application of such a pattern.
The following figure illustrates the architecture for leaf and composite discoverers related to a CSharp metamodel.
Once the composite discoverer has the capability to retrieve information about source regions visited and associated code model elements, it will instantiate the SourceRegion.
Creating one SourceRegion instance for each code model element may induce some memory usage issues. Considering a given code metamodel, it may be interesting to have a strategy for dispatching model elements (from the composition model) into more than one XMI resource file.
Thus, the EMF lazy resource loading mechanism enables opening and working with some subpart of the model.
A reference implementation for this strategy is in the Java Application discoverer.
This component proposes a small framework for synchronizing model element with their source code. The idea is to be able to browse a model of any technology, and to have the possibility to directly navigate to its source code in the right editor.
This framework uses the KDM Extension framework which deals with weaving a model with its source code
The component exposes two extension points for providing a synchronization strategy; those extensions are to be provided for every technology a code synchronization is needed for.
An example of what the result looks like has been implemented for Java. For more information on how to use it see the Java source code synchronization user manual
This extension point aims at declaring strategies to resolve the ASTNodeSourceRegion of an element
public interface SourceStrategy {
public ASTNodeSourceRegion getASTNodeSourceRegion(final EObject eObject);
public boolean isApplicableTo(final Notifier target);
}
ASTNodeSourceRegion of an element. Each strategy has to implement this method because depending on the technology, the ASTNodeSourceRegion information might be contained by the element itself, or by another model such as the MoDisco Composition one
This extension point aims at declaring strategies to open the file which contains the element, and then to select it in its editor.
public interface RevealingStrategy {
public void revealInTextEditor(final IFile file,final SourceRegion sourceRegion);
public void selectInTextEditor(final IEditorPart iEditorPart,final SourceRegion sourceRegion);
public boolean isApplicableTo(final Notifier target);
}
SourceStrategyThis class only maps the event "doubleClick" in the browser in order to call the openAndSelectEObjectInSourceFile method without adding a dependency between the MoDisco Browser and kdm.source.extension.ui
This class extends AdapterImpl to provide a convenient way to manage strategies (
Source/Revealing) for a given element.
A SourceAccessAdapter is added to each element which has to be synchronized with its source code. Thanks to this adapter, strategies are resolved once for an element and then stored in the adapter.
This class extends AdapterFactoryImpl to provide the Adapter mechanism implemented to manage extensions.
Available strategies extensions are stored in a singleton way in 2 static lists:
private static List<SourceStrategy> listSourceStrategy; private static List<RevealingStrategy> listRevealingStrategy;
Then each time we need a strategy we use the singleton pattern to get it.