Chapter 5 Using the PowerDesigner Interface

Using extended dependencies

You can use extended dependencies to specify additional forms of collaborations between PowerDesigner objects. These links are allowed among objects of any type of model, but are not interpreted and checked by PowerDesigner, as they are meant for documentation purposes only.

You can complement these links by creating stereotypes to specify their meaning. Stereotypes are used to define extended dependencies in all PowerDesigner modules, and appear in the Extended Dependencies tab of each non-link object property sheet. You can type them directly in the Stereotype column or select a value from the list if you have previously defined stereotypes in an extended model definition (.XEM) applied to or embedded in the model.

For more information about stereotypes in an extended model definition, see "Working with Extended Model Definitions" in the "Managing Objects" chapter.

Example

The following example illustrates how extended dependencies can help you document relations between package or model objects.

This example about generation from a CDM to two PDMs generated with different DBMS shows that the file object SourceCDM.cdm has extended dependencies with the file objects GeneratedPDM.pdm (for Sybase IQ) and GeneratedPDM2.pdm (for ASA7). These extended dependencies are defined by the <<generation>> stereotype to explain that the two PDM come from the same CDM.

For more information, see the "Using file objects" section in the "Managing Objects" chapter.

Creating an extended dependency

The object from which you create the extended dependency is the dependent object and the object towards which it goes is the influent object.

You can create an extended dependency in either of the following ways:

To create an extended dependency using the Link/Extended Dependency tool:

1. Click the Link/Extended Dependency tool in the Palette.
2. Click inside the dependent object and while continuing to hold down the mouse button, drag the cursor to the influent object where you release the mouse button.

Note that the Link/Extended Dependency tool cannot create an extended dependency between objects belonging to different types of models as these cannot have symbols in the same diagram.

To create an extended dependency from the dependent object property sheet:

1. Open the property sheet of a non-link object, and click the Extended Dependencies tab.
2. Click the Add Objects tool to open the Add Objects dialog box.
3. Select a model from among the models open in the project from the Model box, a package from the list, and an object from one of the sub- tabs.
4. Click OK.
   
   The extended dependency you have created is displayed simultaneously in the list of extended dependencies but also in the diagram if objects at both extremities are displayed.
5. Click the Stereotype column for the extended dependency you have just created and type a stereotype or select a stereotype from the list if available.
6. Click OK.

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