A pattern usually has at least
one parameter although this is not a requirement. Parameters define
the targeted argument's UML type and the acceptable multiplicity bounds.
Each parameter is represented by a Java class and contains the code to perform the work accomplished by
pattern expansion.
Before you begin
You must create a pattern before
you can perform these steps.
About this task
You can specify dependencies between parameters. When
you assign another parameter as a client or supplier parameter, it
dynamically adds the reciprocal assignment to the parameter you are
adding. Thus, moving an existing parameter into the Supplier
Parameter field assigns the role of client to the parameter
you are adding.
To add a parameter to a pattern:
Procedure
- In the Pattern Authoring view, right-click
the pattern and click New Parameter. The New Pattern Parameter wizard
opens.
- Type a name for the parameter in the Name field. The class name is automatically derived
from the parameter name.
- Accept the class name as generated, or modify it in the Class Name field.
- Type a short description of the parameter that can assist
the pattern applier to specify arguments for the pattern. The short description is displayed on the Short Description page of the Pattern Explorer view and as hover
help when the pattern applier hovers over the template parameter on
the diagram view.
- In the Type field, accept the UML
type of Class for the parameter's type or click Browse and select another UML type.
- If the Allowable Subtypes field
is enabled, do one of the following:
- Go on to the next step. All subtypes will be available to
the pattern applier as possible kinds of arguments.
- Click Browse and select the subtypes
that you allow the pattern applier to choose as arguments for this
parameter. For example, for a classifier type, you can choose the
subtypes of interface, class, activity, and collaboration.
- Accept or clear the Allow text entry of argument
value check box that permits the applier to specify an
existing argument or create new argument elements by typing an argument
name.
Note: For parameters that you create with multiple
subtype options, the subtype that is created from the pattern applier's
text entry is controlled by the code you supply in the parameter's
expand or update method. If you do not supply this code, a default
subtype from your allowable subtypes list is selected.
- To add a parameter dependency, complete the following
steps:
- Click the Parameter Dependency tab to open the Parameter Dependency page.
- In the Existing Parameters field,
click one or more parameter names.
- Click a right-arrow button to move the parameter name
into the Client Parameter field or the Supplier Parameter field.
- Click the General tab to return
to the parameter definition or OK to close
the wizard.
Results
The parameter is added to the pattern. As you develop the
pattern, you can modify the parameter properties by using the
Properties view.