Developing Transformation Scripts

Transformation scripts are written in VBScript using a certain number of special methods. Transformation scripts do not require as many checks as standard scripts, because they are always implemented in a new, empty, temporary model, which is merged with the generation target model.

Since a source object can be transformed and have several targets, you may have problems identifying the origin of an object, especially in the merge dialog box. The following mechanism is used to help identify the origin of an object:

If the source object is transformed into a single object, the transformation is used as an internal identifier of the target object.
If the source object is transformed into several objects, you can define a specific tag to identify the result of transformation. You should use only alphanumeric characters, and we recommend that you use a "stable" value such as a stereotype, which will not be modified during repetitive generations.

The following methods are available when writing a transformation script:

```
CopyObject(source [,tag])
```
Duplicates an existing object, sets a source for the duplicated object, and returns a copy of the new object.
```
SetSource(source, target [,tag])
```
Sets the source object of a generated object. It is recommended to always set the source object to keep track of the origin of a generated object.
```
GetSource(target [,tag])
```
Retrieves the source object of a generated object.
```
GetTarget(source [,tag])
```
Retrieves the target object of a source object.

Internal transformation objects are preserved when the transformations are used via the Apply Transformations or a custom menu command, so that they can be re-executed if you subsequently update (regenerate) the model. For example, you generate a CDM entity A to an OOM class B and then apply a transformation to class B in order to create class C. If you make changes to entity A and repeat the generation to update the OOM, class B is updated and the transformation is automatically reapplied to update class C.