Resource Files and Extensions

The PowerDesigner modeling environment is powered by resource files, which define the objects available in each model along with the methods for generating and reverse-engineering them. You can view, copy, and edit these XML-format resource files in order to customize and extend the behavior of the environment.

For detailed information about viewing and editing PowerDesigner resource files see Chapter 1, Resource Files and the Public Metamodel in Customizing and Extending PowerDesigner .

Extension files (*.xem) provide means for customizing and extending PowerDesigner metaclasses, parameters and generation. Extensions are typed like models in PowerDesigner. You create an extension for a specific type of model and you cannot share these files between heterogeneous models. When you create a new model, or when you reverse engineer into a new model, you can select one or several extensions and attach them to the model from the New dialog box.

For example, you can attach XEMs to a Java model to help you in working with a particular IDE, or O/R mapping framework. The XEM may provide objects with additional properties or property tabs, and define additional generation targets and options.

PowerDesigner provides a number of predefined XEMs and you can also create your own.

An extension contains:

For more information about XEMs, including how to create your own, see Chapter 1, Resource Files and the Public Metamodel in Customizing and Extending PowerDesigner .

Missing XEMs

If you rename, move or delete extension files that are attached to a model, you will lose the links between them.

When you subsequently open the model, the following dialog box is displayed to list the XEMs that are not available:

The following tools are available in this dialog box:

Tool	Description
	Open – Lets you browse to, and re-attach, the missing XEMs.
	Update from Repository – Lets you check out the missing XEMs from the repository.
	Delete – Lets you remove the links between the model and the missing XEMs.

• Attaching Extensions to a Model
  You can attach an extension file (.xem) to your model when you create it by clicking the Select Extensions button on the New Model dialog. You can attach an extension file to an existing model from the List of Extensions.