This event is triggered right before a built-in command is executed.

commandId : BuiltinCommand Enumeration [ in ]

The ID of the built-in command to be used.

param : int [ in ]

Some of the commands use parameters. For instance, when the dialog for creating a new object is shown, the object type ID is defined here.

Bool [ out ]

If the UI Extensibility application returns "true", the built-in command can be executed. If "false" is returned, the command is canceled. If nothing is returned, the default value is "true".

Supported in M-Files 2018 and later.