Modeling C++ global variables and methods in a reconciled modeling environment

You can model C++ global variables and methods in UML by applying the «cpp_globals» stereotype to a class in a UML model. You can also generate UML representations of global variables and methods from C++ header files.

Before you begin

You must be in the Modeling perspective. You must have the following items in the workspace:

An open UML model that has the C++ transformation profile applied
An empty C++ project

About this task

This procedure demonstrates how to model C++ global methods and variables in UML and how to transform C++ global variables into UML. The example in this topic assumes a reconciled modeling environment where you begin with a UML model, run the UML-to-C++ transformation, create a global variable in the generated C++ code, and reconcile the changes between the model and code by running the C++-to-UML transformation.

Procedure

Add a class to the UML model that has the C++ transformation profile applied.
Apply the «cpp_globals» stereotype to the class that you created in step 1.
For each C++ global variable or method to create, add a corresponding UML type to the class that you created in step 1. For this example, add a UML operation called Operation1 and an attribute called MAX_LENGTH of type int.
Create a transformation configuration for the UML-to-C++ transformation:
1. Click File > New > Transformation Configuration, and complete the pages in the wizard by using the values listed in the following steps.
2. On the Specify a Configuration Name and Transformation page, from the Transformation list, select the UML-to-C++ transformation, and in the Protocol section, select Reconciled, and click Next.
3. On the Source and Target page, in the Selected source pane, select the UML model that contains the class that you added in step 1. In the Selected target pane, select an empty C++ project, and click Next, and click Next again.
4. On the Mapping page, select the Enable the mapping functionality for this transformation check box.
5. In the Mapping model file name field, specify a name for the mapping model.
6. Click Edit Mapping, specify a location in the workspace and a name for the mapping model, and click OK.
7. Click Edit Mapping.
8. In the Edit the Mapped Names window, select the UML model that contains the class that you added in step 1.
9. In the Mapped name field, specify a name that identifies this mapped element. For example, specify mapped_model; then click Apply, and click OK.
10. Click Next, Next, and Next to accept the default values on the next three pages of the wizard.
11. On the Common page, select the Create trace relationships check box, and click Finish.
The transformation configuration editor opens and shows the new configuration file.
Run the UML-to-C++ transformation: On the Main page of the transformation configuration editor, in the "Forward transformation" section, click Run.
In the Project Explorer view, browse to the target C++ project and open the header file that has the same name as the class that you created in 1. Notice that for each method or variable that you created in step 3, the transformation generates a corresponding C++ global method or variable in the header file.
Add a global variable or operation to the header file, as in the following example: int NEW_MAXLENGTH;.
Reconcile the differences between the model and code: From the Main page of the transformation configuration editor, run the C++-to-UML transformation. In the Merge window, observe the proposed changes to the UML model, which include the global variable that you added in step 7.
Click OK to accept the proposed changes to the UML model. After the transformation runs, notice that the updated UML class now contains the global variable that you added in step 7.