to.etc.domui.component.delayed

Interface IAsyncRunnable

All Known Implementing Classes:

AbstractAsyncRunnable, AsyncDialogTask

public interface IAsyncRunnable

This defines a handler for asynchronous execution within a DomUI page. See AsyncContainer for a component that uses it.

Author:

Frits Jalvingh Created on Sep 1, 2012

Method Summary

Modifier and Type	Method and Description
void	onCompleted(boolean cancelled, Exception errorException) This method gets called with your originating DomUI page "active" when the activity has completed.
void	run(IProgress p) This is the code to call on the newly created worker thread - it should do the long running task that you want to execute in parallel.

Method Detail

run

void run(@Nonnull
         IProgress p)
  throws Exception

This is the code to call on the newly created worker thread - it should do the long running task that you want to execute in parallel. Important: this method will be called on a separate thread, and it will run while the page it is started from is no longer active at all! This means that this task cannot access any of that page's resources! This means:

• You cannot access the shared QDataContext - if you need one you must call QContextManager.createUnmanagedContext() or something similar to create a context usable within this task - and do not forget to release it either!
• You cannot manipulate any of the originating page's data - no fields, and most certainly no components on that page!!!! To show the result of the long running task you must implement onCompleted(boolean, Exception), and use properly synchronized(!) member variables in your IAsyncRunnable implementation to create the new UI to show after the task.

Parameters:

p -

Throws:

Exception

onCompleted

void onCompleted(boolean cancelled,
                 @Nullable
                 Exception errorException)
          throws Exception

This method gets called with your originating DomUI page "active" when the activity has completed. At the time of call you can manipulate any kind of structure within your page. This method is to be used to handle response rendering only; it cannot be used to release any kind of resource(!) because it will not be called if your page terminated (was shelved/unshelved) before the task finished.

Parameters:

cancelled - When TRUE, the task was cancelled by the user.

errorException - When non-null the run(IProgress) method terminated with an exception, and this is that exception. You are supposed to do something with it since no other indication of that error is reported to the user!! So throw this exception on, or display it on your page.

Throws:

Exception