View source for TaskTree CS23

[[Category:QtCS2023]]

==Session Summary==


==Session Owners==

* Presentation by Jarek
* Minutes taken by Volker

==Notes==

* Introduction to [[TaskTree]]
** generic Qt-based solution for automatic execution of a set of asynchronous tasks
** manages execution of tasks

* [[TaskTree]] class
** emits done signal with result
** executes "recipe" after the task tree has been started

* Recipe
** a value of type "Group"
** doesn't do anything on its own
** encapsulates
*** execution mode (e.g. "sequential", "parallel")
*** workflow policy ("stopOnError")
*** list of tasks
** Group objects can be nested
** Tasks can be of type ConcurrentCallTask<ResultType>, using Qt Concurrency types

* Custom tasks, subclassing TaskAdapter<Type>
** describes how to create an asynchronous task
** E.g. QTimer, QProcess, ConcurrentCall, NetworkQuery, ...
** Naming convention: tasks correspond to task class type, e.g. QProcessTask is a TaskAdapter<QProcess>
** Access task object with task(); reimplement start(), emit done

* Handlers
** custom tasks constructor takes 2 handler arguments (callables/functors): setup handler, done handler

* Storage<DataType> type provides inter-task data exchange
** handlers can capture the storage object
** storage uses a QSharedPointer for the data storage, so capturing by value is ok
** e.g. done-handler writes result to storage, setup-handler of next task reads data from storage

* Demo time