implement-and-register-an-addviadelegate-change-handler-with-baseaddviadelegate-utility-ec2576f.md

Implement and Register an AddViaDelegate Change Handler WITH BaseAddViaDelegate Utility

Implement and register an addViaDelegate change type with its change handler to a control with the BaseAddViaDelegate utility.

With this utility you can use write-delegate functionality for creating new controls using the addViaDelegate action. BaseAddViaDelegate is a generic change handler generator utility. The BaseAddViaDelegate.createAddViaDelegateChangeHandler function creates a complete change handler with all the relevant change handler functionality. You just need to pass some callback functionality.

The change handler generated in this way uses the control-specific write delegate to create the controls to be added. This delegate needs to be registered in the <Control>.flexibility.js file (see the example below). You can use existing write delegates or define a delegate yourself. The controlType property should reference the control type that defines the addViaDelegate action in the design time or the relevantContainer defined in the action declaration.

Sample Code:

Control-specific write delegate definition (part of <Control>.flexibility.js)

DelegateMediatorAPI.registerWriteDelegate({
    controlType: "sap.ui.layout.form.SimpleForm",
    delegate: "sap/ui/comp/smartfield/flexibility/SmartFieldWriteDelegate",
    requiredLibraries: {
        "sap.ui.comp": {
            minVersion: "1.81",
            lazy: false
        }
    }
});

Quick Summary

• Select or create existing write delegate. Example: sap.ui.comp.smartfield.flexibility.SmartFieldWriteDelegate

• Register the write delegate into your <Control>.flexibility.js file (see above). If the flexibility file is newly created, you need to reference it in the library.js file.

• Create your own change handler using the BaseAddViaDelegate utility.

• Register your change handler in the <Control.flexibility.js file. See Registering Change Handlers for UI Changes.