tasks Prototype #2

[ engine overview | whitefrost.com | Stephen W. Cote ]

This prototype demonstrates several methods by which the TaskService handles task dependencies.

When the Create Tasks button is clicked, three tasks are created: test1, test2, and test3. Task test2 was made a dependency of test1, and test3 was made a dependency of test2. Task test1 and test2 both define an action and handler that are functions, while task test3 defines neither. Therefore, test1 can only be completed when the test2 dependency is returned, or when test2 is finished, where the dependency is also returned. Since test3 has no action or handler, it can be started or ended with the same effect as this particular task has no dependencies and nothing to do.

The goal of this prototype is to complete task test1. The following are a few possible combinations that demonstrate how this could be accomplished. Click Create Tasks to get started, Reset Tasks to clear the task data, and Print Tasks to display the current task information, status, and dependencies.

Start task #1, start task #2, [start|end] task #3, handle task #2. Note that if the action for task test2 (test_depends) returned true, the handler would be automatically executed when test3 finished. Because the action for task test1 returns true, the handler for test1 is automatically executed.
Start task #1, end task #3, end task #2. Note that in this case task test1 successfully completes its action and handler, but task test2 does not.
End task #2, End task #1 - test1 will not finish until its dependencies are also returned. Note in this example, neither tasks test2 or test3 were finished.