Developing a DSL Graphical Notation - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 80

Updating the Mapping Definition

The main change we need to make to our mapping definition is to our
Relationship link. Our DSL includes a Type enumeration with three literals:
DEPENDENCY , INCLUDE , and EXTEND . We now have three separate tools for
these relationship types, so we need to create a mapping for each. Begin by mod-
ifying the existing relationship link mapping to be our dependency link, and then
copy/paste the element and adjust for the include and extend mappings. Table
4-6 shows what the dependency mapping looks like after our changes.

Table 4-6 Updated Mindmap Relationship Link Mapping

Element Property Value

Link Mapping Containment Feature Map.elements : MapElement

Element Relationship → MapElement

Source Feature Relationship.source : Topic

Target Feature Relationship.target : Topic

Diagram Link Connection Relationship

Tool Creation Tool Dependency

Constraint Body self.type = Type::DEPENDENCY

Feature Seq Initializer Element Class Relationship → MapElement

Feature Value Spec Feature Relationship.type : Type

Value Expression Body Type::DEPENDENCY

Language ocl

Feature Label Mapping Diagram Label Diagram Label RelationshipName

Features MapElement.name : EString

Feature Label Mapping Diagram Label Diagram Label RelationshipType

Features Relationship.type : Type

View Pattern «{0}»

As you can see, the link mapping now has some additional child elements.
First, we add a Constraint to indicate using OCL that self.type =
Type::DEPENDENCY . This enables us to identify each of our Relationship
mappings so that the generator can create code to distinguish nodes based on
their type attribute. Also, we add a Feature Seq Initializer child element