Observer (event hook) for media or images

Question

I want to create a module that will hook events for images being added to products or vendors etc so that when it's saved and was already an existing image (image was being updated) - that it would invalidate that image (in cloudfront).

What events would allow me to detect this; maybe extend the image.php where it saves the image? Currently I don't see any dispatched events that will help me;

I tried: core/Mage/Catalog/Model/Product/Attribute/Backend/Media.php:277:

Mage::dispatchEvent('catalog_product_media_add_image', array('product' => $product, 'image' => $file));

But found that the event is not dispatched when adding an image to a product. But technically - I only need to know about changed images - is there a way for me to detect (by hooking the before or after product save event) what properties have been updated?

Any direction would be greatly appreciated.

Answer 1

Try the event catalog_product_gallery_upload_image_after this should be fired on the upload action of the controller Mage_Adminhtml_Catalog_Product_GalleryController from your question I think this is the right event for you.

Answer 2

First the credit https://stackoverflow.com/questions/8182009/get-product-changes

Now the solution. Hook into the catalog_product_save_before event and use the following observer to work out if images have changed.

class Custom_Module_Model_Observer {

public function handleProductSaveBefore(Varien_Event_Observer $observer)
{
    $product = $observer->getEvent()->getProduct();
    $diff = $this->_compareArrayAssocRecursive($product);

    if($this->hasImageChange($diff)) {
        //do stuff
    }

    return $observer;
}

protected function _compareArrayAssocRecursive($product)
{
    $diff = array();
    $attributes = $product->getTypeInstance(true)->getEditableAttributes($product);

    foreach ($attributes as $key => $value) {
        if ($product->dataHasChangedFor($key)) {
            $diff[$key] = $product->getData($key);
        }
    }

    return $diff;
}

public function hasImageChange($diff)
{
    $images = $diff['media_gallery']['images'];
    if($images) {
        $images = Zend_Json::decode($images);
        foreach($images as $image) {
            if(! $image['value_id'] || $image['removed']==1) {
                return true;
            }
        }
    }

    return false;
}

}

I thank you.