[emfindex-dev] Contributing the QVT Declarative Model Registry to EMF In

[Ed Willink <ed@xxxxxxxxxxxxx>]

Hi

Tool support for OCL or QVTc or QVTr must perform a two level model name 
resolution.

a) name to nominal URI
b) nominal URI to precise URI

In OCL a package context specifies a package name without specifying 
where that package may be located.
In QVTc or QVTr a transformation references a meta-model name again 
without specifying where that meta-model may be located.

The (originally UMLX) QVT Declarative Model Registry supports a) and b) 
by prioviding a per-project set of registrations that are scoped by 
resources (File or IResource), allowing a user to provide registrations 
with project, folder or file granularity. Registrations are defined for 
a chosen Model Accessor namespace, so that Model Name registrations map 
from ad hoc name such as myUML to nominal URI such http://my.uml, and 
URI registrations map from nominal URI to precise URI e.g. 
platform://resources/myuml/model/uml.ecore.

The Model Name accessors are completely user defined.
The URI accessors enhance the built-in EPackage.Registry resolutions 
with user defined mappings for models that need not be reified as Java code.

The registry is persisted as an EMF model in 
.settings/org.eclipse.qvt.declarative.modelregistry
The GUI supports  maintenance of registrations  using a Property Page.
The API supports locating registrations and/or loading a resolution.

This functionality seems mostly complementary to EMF Index, so it seems 
desirable to revise the current Model Registry code so that it can be 
contributed to EMF Index. This will avoid migrating the QVT Declarative 
Model Registry to MDT OCL as would be required to support the migration 
of the OCL editor.

A fuller write up of the Model Registry with pictures may be found in 
the EclipseCon 2008 submission 
http://www.eclipse.org/gmt/umlx/doc/EclipseAndOMG08/ModelRegistry.pdf.

   Regards

      Ed Willink