Python Callback System

Python Callback Systemedit

The CallbackExt extension provides Python callback functionality to custom components. All callbacks will be passed a single argument containing an info dictionary. Callbacks can be defined in the DAT named in the Callback DAT parameter. To report all callbacks to the textport, turn on the Print Callbacks toggle parameter. The Callback DAT and Print Callbacks parameters are often found on the Callbacks parameter page, but their location can be customized.

The info dictionary always contains an "ownerComp" key. It will also have a "callbackName" key holding the callback name. It will sometimes contain an "about" key, describing the callback, and should always contain this key if a return value is expected. Generally, callbacks are called AFTER the internal method they are associated with, to allow over-riding of whatever that method does.

See also: CallbacksExt Extension