The 'onOpen' callback

Event number: 26
Generated for: Any object

The onOpen callback is invoked after an object has been opened.

For the System object, the onOpen event has a special meaning. If you have packaged your APL workspace into a standalone application, this event is triggered under MacOS when the user drags a file icon on to your application icon, once the application is running. (It is not triggered when the application first starts up, and is not triggered under Windows). The file and action properties indicate what files you need to open or print.