Event like EVENT_BEFORE_ADD_LINE_ITEM that covers CP additions

[GaryReckard]

I’m using the Order::EVENT_BEFORE_ADD_LINE_ITEM event to do several things, one of which is to keep two types of products from existing in a cart at a time, or blocking a certain line-item if the user meets certain criteria.
This works great for when a user adds the line item on the front-end… but this doesn’t seem to get triggered when an admin adds a line item in the CP when manually creating an order. Anybuddy know of a similar event that will catch admin additions in the CP, or another route to take for that?
Thanks!

[StijnCoolen]

@GaryReckard unfortunately I dont't have an answer but are you able to share the code you use to "keep two types of products from existing in a cart at a time". This is exactly what I'm trying to do.

[GaryReckard]

Hi @StijnCoolen

Sure! So, In my custom module, I have a line

        Event::on(Order::class, Order::EVENT_BEFORE_ADD_LINE_ITEM, new BeforeAddLineItemHandler);

And in that BeforeAddLineItemHandler, an __invoke method like so:

    public function __invoke(AddLineItemEvent $e)
    {
        $lineItem = $e->lineItem;
        $cart = $e->sender;

        // do not allow both an individual and a team subscription in the cart at the same time
        if ($lineItem->isSubscription && $cart->hasTeamSubscriptionProduct) {
            Craft::info('BeforeAddLineItemHandler: You already have a Team Subscription in your cart. You cannot add an Individual subscription.', 'order_debug');
            $e->isValid = false;
            Craft::$app->getSession()->setError('You already have a Team Subscription in your cart. You cannot add an Individual subscription.');
            return;
        }


        if ($lineItem->isTeamSubscription && $cart->hasSubscriptionProduct) {
            Craft::info('BeforeAddLineItemHandler: You already have an Individual Subscription in your cart. You cannot add a Team subscription.', 'order_debug');
            $e->isValid = false;
            Craft::$app->getSession()->setError('You already have an Individual Subscription in your cart. You cannot add a Team subscription.');
            return;
        }


        if ($lineItem->isProfessionalSubscription && $cart->hasProfessionalSubscriptionProduct) {
            Craft::info('BeforeAddLineItemHandler: You can only add one Professional Subscription.', 'order_debug');
            $e->isValid = false;
            Craft::$app->getSession()->setError('You can only add one Professional Subscription.');
            return;
        }

        ...
    }

Making use of Behaviors on LineItem and Order (cart), that look something like this one on LineItem, for instance:

	public function getIsProfessionalSubscription()
	{
		$lineItem = $this->owner;
		return isset($lineItem->snapshot['product']['slug']) ? $lineItem->snapshot['product']['slug'] == self::PROFESSIONAL_PRODUCT_SLUG : false;
	}

That LineItemBehavior is defined in my module like so:

        Event::on(LineItemModel::class, LineItemModel::EVENT_DEFINE_BEHAVIORS, function (DefineBehaviorsEvent $event) {
            $event->sender->attachBehaviors([
	            'line-item-behavior' => LineItemBehavior::class,
            ]);
        });

... Also have a similar behavior on the Order class.

Hope that helps!