Magento EDA system how to avoid event loop?

Question

I am trying to hook catalog_product_save_after event. Here is config.xml

<events>
   <catalog_product_save_after>
     <observers>
       <observer_name_here>
         <class>My_Class_Model_Observer</class>
         <method>methodToCall</method>
         <type>singleton</type>
       </observer_name_here>
     </observers>
   </catalog_product_save_after>
</events>

And below is the code that runs in methodToCall():

$product = Mage::getModel('catalog/product')->load(1);
$product->setName('TESTING 123');
$product->save();

Issue Is:
When the event catalog_product_save_after is fired. The code written in methodToCall() fire the catalog_product_save_after again. And according Magento EDA system methodToCall() called again which fires the catalog_product_save_after once again. So the system stuck in series of firing and listening the same event.

My Questions:

How to avoid this situation ?
Is there any way to disable to Magento event dispatch functionality for temporary purposes (without re-writing dispatchEvent method of Mage_Core_Model_App if possible).
How to prevent infinite looping, if the observer fires the same event that instantiated the observer. Like in case above.

Why don't you use catalog_product_save_before event? Can you explain more what are you trying to achive in your method, maybe we can offer an alternative solution rather than trying to disabling event dispatches. — muhammedv, Apr 18 '16 at 12:37
@muhammedv If I use `catalog_product_save_before` the same thing gonna happen. The issue is EDA system, What if the observer fires the same event. How to prevent system to get into the looping. — ROBIN, Apr 18 '16 at 12:47
If you use catalog_product_save_before, you won't call $product->save(); It will be saved after. Just get product with $product = $observer->getEvent()->getProduct(); in the event observer method and call setName() and don't call save(). It will be saved. Test it. — muhammedv, Apr 18 '16 at 12:50
That's cool. But i have to use the new values and using those values I have to update another product. That's why I can't use the **catalog_product_save_before** event. — ROBIN, Apr 18 '16 at 12:52
Also you can get old values by calling $product->getOrigData(); — muhammedv, Apr 18 '16 at 12:54
Also you can check if there is a data change in product model by calling $product->hasDataChanges() — muhammedv, Apr 18 '16 at 12:54
Agree! What I seeking for solution for this looping situation. Can we built something in Magento that can disable all the dispatching functionality temporary ? I am trying with re-writing the dispatchEvent function. — ROBIN, Apr 18 '16 at 12:57
Yeah that I can see :) But I am not avoiding this situation. I am looking for a solid solution for this. — ROBIN, Apr 18 '16 at 13:01
ROBIN, calling save function in catalog product save observer is wrong. You need to find another way to achive what you want, not a way to disable event dispatching functionality temporarily. — muhammedv, Apr 18 '16 at 13:02

score 0 · Answer 1 · answered Apr 18 '16 at 13:00

If you have to use the new values and using those values you have to update another product you can observe catalog_product_save_before event. Your config looks OK, here you are an example methodToCall function:

public function methodToCall(Varien_Event_Observer $observer)
{
    $event    = $observer->getEvent();
    $product  = $event->getProduct();

    if($product->hasDataChanges()) { //somethings changed

        $newName = $product->getName();
        $oldName = $product->getOrigData('name');

        //do stuff here
        //don't call $product->save() It WILL be saved. If you call save() you will create a loop
    }
}

score 0 · Answer 2 · answered Apr 18 '16 at 14:51

I believe fundamentally, this is probably the wrong approach for your use case, I think you should probably be looking at save_before. However, I've seen people use the Mage::registry for this in the past.

if(!Mage::Registry("somekey")) {
    Mage::Register("somekey", true);
    //LOGIC
}

Now, in this instance, "somekey" should be something specific, and probably specific to this product too so that if you're saving multiple products, it doesn't affect them.

Magento EDA system how to avoid event loop?

2 Answers2