Viewpoint Guidelines

To avoid performance issues, some guidelines must be followed.

Use representation descriptor instead of representation

When an extension needs to retrieve representations (representation targeted by an element, representation per kind, representation that will be visible in documentation...) or need to store additional information about representations, please use their representation descriptors as much as possible instead of using/storing it in the representation.

Indeed, in a Team for Capella context, a representation is not loaded until it is accessed through descriptor.getRepresentation() (which is the case when the user opens a representation), only its descriptor is. Descriptor may contains the required information that fulfill your needs about representations without have to load the content of the representation and can also be used to store information about it.

Please also refer to Capella Release Notes.

Diagram extensions

Expressions in .odesigns

For performance reasons, when writing expressions in .odesigns it is recommended to:

• Use Java services,
• Use AQL expressions,
• Not use Acceleo 2 expressions (Acceleo 2 is deprecated).

Semantic Candidate Expression

This expression called at each diagram refresh should be the most efficient possible. It can be computed based on the displayed graphical elements using the variable *diagram*. When 'Import Mapping' are used, please ensure that semantic candidate expression has been updated accordingly to the semantic candidate expression of the imported mapping

Create Generic Viewpoints

Create Generic Viewpoints using:

• Sirius capability to extends several diagrams at one time with regular expressions extensions
• Diagram Styles Customization Feature allowing to customize the style of elements based on expression. (for instance, on all "Functions called 'Deprecated'", set color as gray)

Avoid EObject.eResource calls

On EObject, you have to avoid as much as possible calls to eObject.eResource()

Contribute an ID handler

If your metamodel elements doesn't inherit from org.polarsys.capella.common.data.modellingcore.ModelElement, you have to contribute an Id handler via the extension point "org.polarsys.capella.shared.id.handler.IdHandler" You can simply extend the org.polarsys.capella.shared.id.handler.AbstractIdHandler.