The customerForm.cls file that you will add to the project in this section is an ABL Form that implements the Customer window in the application.

An ABL Form is one of the visual containers that you can create in the Visual Designer. The ABL Form implements a non-modal window in an application. Non-modal means that the window can be active while other windows are also active. The Customer, Department, and Purchase Order windows in the sample application are all non-modal ABL Forms.

To add customerForm.cls to the project:

  1. In the Project Explorer view, expand the openedge node in the SampleApp project.
  2. Right-click on the ui node in the tutorial folder.
  3. From the context menu, select New > ABL Form, as shown in the following illustration:


  4. In the New ABL Form wizard, enter customerForm in the Form name field.
  5. Click Add (next to the Implements field). The Interface Selection dialog appears.
  6. Select IUpdatable.openedge.tutorial.ui from the Matching interfaces list in the Interface Selection dialog.
    Note: If you do not see IUpdatable.openedge.tutorial.ui on the list, compile the project. Right-click on SampleApp in the Project Explorer view, and choose Progress OpenEdge > Compile.

    IUpdatable is an interface. An interface is a .cls file that declares prototypes for methods but does not actually define those methods. Since you declared that customerForm implements IUpdatable in this step, you will eventually need to define the methods declared in IUpdatable. (For more information about interfaces and other object-oriented programming concepts, see OpenEdge Development: Object-oriented Programming.)

  7. Click OK to return to the New ABL Form wizard. The New ABL Form dialog appears, as shown in the following illustration:


    A customerForm.cls file is added to the project under the ui folder. The file appears in the Design Canvas of the Visual Designer and will look similar to the following illustration:



Note: If you look at customerForm.cls in the ABL Editor, you can see the preliminary implementation of the methods specified in the interface file, IUpdatable.cls. To see customerForm.cls in the ABL Editor, select customerForm in the Visual Designer and press F9. The methods specified in IUpdatable.cls are AddRecord(), DeleteRecord(), SaveRecord(), and CancelUpdate(). Adding interface methods explains how to complete the implementation of these interface methods.