Developing Model-to-Model Transformations - Eclipse Modeling Project: A Domain-Specific Language Toolkit - page 250

having it implemented in our model makes the script cleaner and eliminates the
need to repeat the code here, in code generation templates, and so on. The root
Topic elements are each mapped to RequirementGroup elements using the fol-
lowing toRequirementGroup() mapping. From the updated transformation
declaration shown previously, you can see two properties used as counters to
generate group and requirement indexes.

mapping mindmap::Topic::toRequirementGroup() :

requirements::RequirementGroup {
init {
result := object requirements::RequirementGroup {
name := self .name;
id := 'G0' + this .grpCtr.toString();
requirements += self .subtopics. map toRequirement();

}

}
end {
this .grpCtr := grpCtr + 1;

}

}

A straightforward map of the Topic name attribute to the
RequirementGroup name attribute is followed by an invocation of the
toRequirement() mapping for each of the subtopic references. This is this final
mapping in our transformation:

mapping mindmap::Topic::toRequirement() : requirements::Requirement {
title := self .name;
children += self .subtopics. map toRequirement();
id := 'R0' + this .reqCtr.toString();
version := object requirements::Version {
major := 1;

};
dependencies += this .dependencies-> select (source = self ).target. late
resolveIn (mindmap::Topic::toRequirement,
requirements::Requirement);

end {
this .reqCtr := reqCtr + 1;

}

}

The Topic name attribute maps to the Requirement title , as subtopics are
recursively mapped to child Requirement s. The Requirement dependencies
reference is populated with Requirement objects created from Topic elements
that are targets of mindmap DEPENDENCY relationships collected earlier. We can-
not guarantee that these Topic elements have been already mapped to