Before you create a REST Web application from your existing ABL application, you have to:

  • Ensure that your ABL application is state-free.
  • Gather information about the ABL resources that you want to expose as REST resources.
Note: A REST Web application can only use services from one OpenEdge project. You must determine the project that you want to use for creating a REST Web application.

State-free application

A REST Web application is state-free. To create a REST Web application from your existing ABL application, you must ensure that:

  • For procedure files that contain internal procedures, the top-level procedure does not define parameters and state is not maintained between calls to internal procedures and functions.
  • Each class is designed to run as a singleton.

Planning

You should create a checklist of the ABL resources in your application that you want to expose as REST resources. From those ABL resources, make a note of:

  • The input and output parameters of ABL operations
  • REST service URI naming conventions
  • The HTTP verb that you will associate with each operation

Making a note of these will be helpful when you create your REST Web application in Developer Studio.