IAsyncActionProvider (ITF)¶
INTERFACE IAsyncActionProvider EXTENDS __SYSTEM.IQueryInterface
Separated from the implementation of a function block for abstracting a background task (BackgroundTask),
a additional interface for describing actions (IAsyncActionProvider
) was introduced.
New parameters for the current action will be passed by the itfParam
input of the IAsyncActionProvider.AsyncAction method.
The value is taken from a queue (See: itfParams
of BackgroundTask). This way the AsyncAction
is decoupled from foreground task processing.
The processing of the action can take several cycles.
At the end of processing, the output xComplete`
is set to TRUE
and the result of the action
is made available to the foreground task via the IAsyncActionProvider.AsyncResult property.
Properties:
Methods:
Structure: