= Generating Code from Models =

If a ModelModule is set up according to the instructions in [wiki:Docs/CreatingNewModelModule Creating a New ModelModule], the default !InfoGrid build process should automatically generate the appropriate code when the project is built.

The !InfoGrid CodeGenerator is contained in [wiki:Module] `org.infogrid.codegen` in [wiki:Projects project] [wiki:Projects/ig-graphdb Graph Database]. From the root directory of a [wiki:Docs/SubversionBranches Subversion branch], if `ig-graphdb/tests/org.infogrid.model.Test` is the ModelModule, it can be invoked as follows:
{{{
java -classpath ig-utils/modules/org.infogrid.module/dist/org.infogrid.module.jar:ig-utils/modules/org.infogrid.module.commandline/dist/org.infogrid.module.commandline.jar
     -rootmodule org.infogrid.codegen
     -moduleadvertisementpath */*/*/dist/*.adv
     ig-graphdb/tests/org.infogrid.model.Test
     -o ig-graphdb/tests/org.infogrid.model.Test/build/module-generated/
}}}

Here is an outline over the generated code:
 * For each SubjectArea named '''`XXX`''' (e.g. `org.infogrid.model.Test`), the following Java packages are created:
   * '''`XXX`''', containing the generated interfaces (e.g. `org.infogrid.model.Test`)
   * '''`XXX`'''.'''`VERSION`''', containing the generated implementations (e.g. `org.infogrid.model.Test.V`)
 * In the SubjectArea's top package, the class '''`XXX`'''`SubjectArea` representing the SubjectArea itself is created, if the SubjectArea is named '''`XXX`'''.
 * For each EntityType with the short name '''`YYY`''' (e.g. `SimpleBlobTest`), a Java interface is created with the same name '''`YYY`''' (e.g. `SimpleBlobTest`).
 * For each EntityType with the short name '''`YYY`''' (e.g. `SimpleBlobTest`) that is not abstract, a Java class is created with the same name '''`YYY`''' but prefixed with `Impl` (e.g. `ImplSimpleBlobTest`)
 * For each EntityType with the short name '''`YYY`''' (e.g. `SimpleBlobTest`) that is abstract but marked as a possible ForwardReference, a Java class is created with the same name '''`YYY`''' but prefixed with `Impl` (e.g. `ImplSimpleBlobTest`)
 * No class or interface is generated for a RelationshipType.
 * For each PropertyType with the short name '''`ZZZ`''' (e.g. `LastName`), a getter method is generated according to !JavaBeans conventions (e.g. `getLastName`).
 * For each PropertyType with the short name '''`ZZZ`''' that is not read-only (e.g. `LastName`), a setter method is generated according to !JavaBeans conventions (e.g. `setLastName` );

In addition, for each MeshType, a static declaration is generated in the SubjectArea class, such as:
{{{
public static final EntityType SIMPLEBLOBTEST = ...
public static final RelationshipType RR = ...
}}}

These static declarations make it easy to refer to [wiki:Model] information in application code. For example, to traverse RelationshipType `RR` from source to destination, one can simply refer to the static constants like this:
{{{
MeshObject    start          = ...
MeshObjectSet destinationSet = start.traverse( TestSubjectArea.RR.getSource() );
}}}