Choose not to save an element on EVENT_BEFORE_SAVE_ELEMENT

Question

I want to do some server side checks to see if the entry should be saved or not.

In my plugin I have something like that

Event::on(
    Elements::class,
    Elements::EVENT_BEFORE_SAVE_ELEMENT,
    function(ElementEvent $event) {
        if ($event->element instanceof \craft\elements\Entry) {
            $entry = $event->element;
            if ( $entry->sectionId == 5 ) {
                $entry->enabled = 0;
            }
        }
    });

This works but what I want is for the entry to not be saved rather then be disabled. Something I could achive on the user model with:

$event->isValid = false;

Is there a way to withhold the entry from saving? The only other solution I can think if is to make the tests in the AFTER event and delete it if not passing the condition.

Answer 1

This functionality or behavior is a bit confusing. The Elements Service has its own Events for saving Elements, specifically... but because ultimately Elements are just Yii Models, they have a discrete EVENT_BEFORE_SAVE event that uses a ModelEvent, which has the isValid property.

This is the point in the life-cycle where saving the Element can be prevented. The beforeSave method is called on the Element being saved (usually overridden in the actual Element implementation, but called + returned at the end of the subclass's method, like parent::beforeSave($isNew)), and the resulting boolean ($event->isValid) determines whether or not the saving continues.

So, in short: You can listen directly to the Entry's EVENT_BEFORE_SAVE event to prevent it from saving:

use craft\elements\Entry;
use craft\events\ModelEvent;

use yii\base\Event;

Event::on(
    Entry::class,
    Entry::EVENT_BEFORE_SAVE,
    function(ModelEvent $event) {
            $entry = $event->sender;
            if ($entry->sectionId == 5) {
                $event->isValid = false;
            }
        }
    });