Developing a DSL Abstract Syntax - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 42

Aggregation links create a reference with the Containment property set
to true , in contrast with Association links, which are noncontainment
references.
Setting the upper bound property of a link to -1 creates a many relation-
ship and causes the link to be displayed with the familiar 0..* notation.
References with eOpposites are shown in Figure 3-4 as a single connec-
tion, whereas the Ecore diagram shows two separate links.

3.3.3 Creating the Mindmap Generator Model

With our mindmap.ecore model complete, we can validate it and create a gen-
erator model. To validate it, open the model in the Sample Ecore Model Editor
and right-click on the root package. Select Validate and confirm that no errors
exist. If there are errors, correct them and continue. We look into adding valida-
tion for our mindmap model later, which leverages a similar validation frame-
work provided for all Ecore models.
To create mindmap.genmodel , right-click the mindmap.ecore file in
Explorer view and select New

→ Other → Domain-Specific Language → Domain

Generator Model (Ctrl+3 → Domain Gen). Note that the original EMF wizard

is found in New → Other → Eclipse Modeling Framework → EMF Model

(Ctrl+3 EMF Model). We started by selecting our mindmap.ecore model ,

so the wizard defaults to the same folder and provides the name we want. It also
recognizes that we are importing an Ecore model, but we have to load it our-
selves, curiously. We have only one root package, so we can finish the wizard and
take a look at the generator model properties.
EMF generator models include several properties to consider. For our
mindmap, we need to change only a couple from their default settings. In the
root, change the Compliance Level from 1.4 to 5.0 (if it's not already set to
5.0) and change the Model Directory to be /org.eclipse.mindmap/src .
(Note that this changes the edit, editor, and tests properties as well.) We need to
manually change the Model Plug-in ID property to org.eclipse.mindmap ,
however. In the properties for the Mindmap root package, we need to set the
Base Package property to org.eclipse to match our new plug-in namespace.
This gets us started, so we can move on to code generation. Later, we return
to our mindmap model and add constraints, validation, and other enhancements.

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