Scheduled Task - Plugin to use Rules

Question

I'm trying to set up a custom scheduled task and I want to utilise the Rules parameters as part of my logic to get other records from the database.

So my question is how do I get the json rules? I've tried the following in my mytaskTask.

private function mytaskTask(ExecuteTaskEvent $event) : int
{
    // Your task goes here
    $taskType  = $event->getArgument('routineId');

    // get the rules
    $db    = $this->getDatabase();
    $query = $db->getQuery(true);
    $query->select(' execution_rules ' );
    $query->from($db->quoteName('#__scheduler_tasks'));
    $query->where($db->quoteName('type').' = '.$db->quote($taskType) );
    $db->setQuery($query);
    try {
        $rules = $db->loadResult();
        $this->logTask('Retrieved task rules', 'notice');
    } catch (RuntimeException $e) {
        $this->logTask($e->getMessage());
        return Status::KNOCKOUT;
    }
    $rulesObj = json_decode($rules);
    $ruleType = $rulesObj->rule-type;

UPDATED: So now I'm able to get the rules as a JSON string in $rulesObj however when I try to get the rule type I get the terminated dialogue box with the message:

JSON.parse: unexpected character at line 1 column 1 of the JSON data

When I display the variable $rulesObj I see the result as:

stdClass Object
(
    [rule-type] => interval-days
    [interval-days] => 1
    [exec-day] => 21
    [exec-time] => 05:19
)

As usual, all guidance appreciated.

Answer 1

Apparently, the entire task object is passed to the event but there is no proper method for retrieving it. So you have to resort to using getArgument():

$rules = $event->getArgument('subject')->get('execution_rules');

If you need the JSON string, simply run the result through json_encode().

Answer 2

Looking at the code in /administrator/components/com_scheduler/src/Task/Task.php the execution_rules aren't included in the event. So going from the code there:

$event = AbstractEvent::create(
    'onExecuteTask',
    [
        'eventClass'      => ExecuteTaskEvent::class,
        'subject'         => $this,
        'routineId'       => $this->get('type'),
        'langConstPrefix' => $this->get('taskOption')->langConstPrefix,
        'params'          => $this->get('params'),
    ]
);

I think you'd need to get the routineId which seems to match the 'type' column in the database table:

[$subject, $routineId, $langConstPrefix, $params] = array_values($event->getArguments());

Then you'd need to find the execution_rules either by doing a database query along the lines of:

select execution_rules from #__scheduler_tasks where type = $routineId; 

or you could load the record via the TaskTable class in Joomla\Component\Scheduler\Administrator\Table\TaskTable, and that should set up the execution_rules property of the Table instance.

I haven't checked all this though...