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Background documentationFreely Programmed Value Help Locate this document in the navigation structure

 

Web Dynpro ABAP Framework allows you to create your own input help components. A component to be used as value help must implement interface IWD_VALUE_HELP (see Working with Web Dynpro Component Interfaces). Once the freely programmed value help has been linked to a context attribute, the value help is automatically available for every InputField linked to this attribute.

Interface IWD_VALUE_HELP

When programming with interface IWD_VALUE_HELP, take note of the following:

  • Method SET_VALUE_HELP_LISTENER for interface controller of IWD_VALUE_HELP can be called only by Web Dynpro Framework. The framework uses this method to pass a callback interface to the value help component. The value help component can use this interface to tell the framework that it is to be closed, for example, if data has been selected, if Cancel has been pressed, or if an error has occurred. This interface contains the two attributes F4_CONTEXT_ELEMENT and F4_ATTRIBUTE_INFO as well. They describe the context element for which the F4 help has been requested.

  • Events VH_WINDOW_CLOSED and VH_WINDOW_OPENED of the component interface may only be triggered by the framework. The events indicate the points in time when the input help window is closed or opened. When implementing component interface IWD_VALUE_HELP, these events should be copied to the component interface of the value help component to make them available in the calling component, and to allow its event handlers to register these events.

  • Component interface IWD_VALUE_HELP has interface view WD_VALUE_HELP. The views to be displayed in the value help window must be embedded into window WD_VALUE_HELP, which belongs to the interface view.

  • Once the value help component has been created by Web Dynpro Framework, method SET_VALUE_HELP_LISTENER is called (also by the framework) so that interface IF_WD_VALUE_HELP_LISTENER can be passed to the value help component. This interface contains method CLOSE_WINDOW. This method can be used to close the value help window.

Attachment to a Context Attribute

You attach a freely programmed input help in analogy to the attachment of an OVS input help by following these steps:

  1. Creating an input help component and implementing the component interface IWD_VALUE_HELP.

  2. Creating a component usage for the input help component in your application component.

  3. Attaching the component usage to the context attribute. In this case, for the input help mode choose free (either when creating the attribute or later in its properties table) and specify the respective component usage.

Context Change Log for Freely Programmed Input Help

When you work with a freely programmed input help, you can still use the function Context Change Log. Note, however, that the values selected by the user are not automatically written to the change table; you need to program the entry explicitly (see OVS Value Help and Context Change Log).