Commands (fka Operations)¶

In Contao 2 and Contao 3 operations are normal buttons with a url. In DcGeneral, operations are more like commands.

If a command is triggered by user action in the view, the command will be dispatched as CommandEvent on the server side. Each listener must now decide what he need to do on the command. If a listener handle the event, he might stop it’s propagation.

Here is an extreme simplified pseudo example of the default item edit listener.

function defaultItemEditHandler(DcGeneral\Event\ItemCommandEvent $event) {
    $model       = $event->getItem();
    $view        = $event->getEnvironment()->getView();

    $view->redirect('contao/main.php?act=edit&id=' . $model->getId());
    $event->stopPropagation();
}

See CommandEvent and all of it’s sub-classes for reference about command events.

Predefinition¶

The priority of default command listeners, that handle the default behaviour is 0. If you want to overwrite the default behaviour, register your listener with a priority greater than 0. If you want to post process the default behaviour (keep in mind that some commands stop event propagation), register your listener with a priority smaller than 0.

Scopes¶

Container scope¶

Container scoped commands are related to the data definition container and do some action on it.

Event: DcGeneral\Event\CommandEvent

Model scope¶

Model scoped commands are related to a model and do some action on it.

Event: DcGeneral\Event\ModelCommandEvent

Indexed command events¶

Command events are indexed with the container name or with command name or with container name and command name. The event name will be dc-general.command[<container name>], dc-general.command[<command name>] or dc-general.command[<container name>][<command name>], e.g. dc-general.command[tl_example], dc-general.command[edit] and dc-general.command[tl_example][edit].

Read more about indexed events in the Events chapter.

Examples¶

listen on edit command event on tl_example¶

$GLOBALS['TL_EVENTS'][DcGeneral\Event\CommandEvent::NAME][] = function(DcGeneral\Event\CommandEvent $event) {
    if ($event->getName() == 'edit') {
        $environment = $event->getEnvironment();
        $container   = $environment->getDataDefinition();
        if ($container->getName() == 'tl_example') {
            ...
        }
    }
}

listen on indexed edit command event on tl_example¶

$GLOBALS['TL_EVENTS'][DcGeneral\Event\Command::NAME . '[tl_example][edit]'][] = function(DcGeneral\Event\CommandEvent $event) {
    // the name check is not needed anymore
    $environment = $event->getEnvironment();
    $container   = $environment->getDataDefinition();
    // the container name check is not needed anymore
    ...
}

listen on all indexed command events for tl_example¶

$GLOBALS['TL_EVENTS'][DcGeneral\Event\Command::NAME . '[tl_example]'][] = function(DcGeneral\Event\CommandEvent $event) {
    // if necessary, do a command name check here
    $environment = $event->getEnvironment();
    $container   = $environment->getDataDefinition();
    // the container name check is not needed anymore
    ...
}

listen on all indexed edit command events¶

$GLOBALS['TL_EVENTS'][DcGeneral\Event\Command::NAME . '[edit]'][] = function(DcGeneral\Event\CommandEvent $event) {
    // the name check is not needed anymore
    $environment = $event->getEnvironment();
    $container   = $environment->getDataDefinition();
    // if necessary, do a container name check here
    ...
}