Via userexits at keys you can have DataView execute a function as a reaction on certain keys. Thus you create a keyboard event.
All userexits at keys are on_event-userexits, because at keys the internal event detecting routine of DataView passes only one trigger, the on_event-trigger. DataView will execute the function if the user presses the key or key combination. After executing the function program control is returned to the general event loop.
With additionally defined keyboard events you can improve the options of the user interface for experienced users. You accomplish this by offering a single keypunch for repeatedly required program functions, which else would only be available via a sequence of sub-menus.
If you want to use this method to assign keys to editing, query, or deleting functions for masks, you may only define the keyboard event for system states or work modes, in which the userexit called can be usefully applied. If, for instance, you want to use the standard userexit dal_iwf_edt_lis to quickly shift a mask into mask edit state via a key, you should only allow the keyboard event for widget- or element selection state. Only in these states the userexit can prepare the mask for editing data.
In addition to the userexit name you can pass a parameter string at the on_event-trigger of a key.