How to set selected value in multiselect attribute

Question

How to set selected value in multiselect attribute progmatically. I tried this one but it doesn't work for me.

How to Programmatically set a Product's Multi-Select Attribute by Labels

the code on the link above doesn't stop from loading

$productObj = Mage::getModel('catalog/product')->load($product->getId());
$productObj->setData('filter_category','51,52');
$productObj->save(); 

the code above is invoke after catalog_product_save_after

• Tim Bezhashvyly: Please post the code of your implementation. Also mention where is it located.
• Marius: The code looks OK. I think you should try it on the _save_before event.
• Netorica: @Marius but I need the updated data of the product...
• Amit Bera: @marius is right,if you want this using catalog_product_save_after then it going infinite loop
• Fabian Schmengler: Please take your time to accept an answer if it helped you. magento.stackexchange.com/help/someone-answers

Answer 1

Since you want to do this in the action catalog_product_save_after you could simple update the individual product attribute and not the complete product, thus stopping the infinite loop problem.

$attrCode = 'your_attribute';
$sourceModel = Mage::getModel('catalog/product')->getResource()
 ->getAttribute($attrCode)->getSource();
$valuesText = explode(',', 'red,green,blue');
$valuesIds = array_map(array($sourceModel, 'getOptionId'), $valuesText);
$product->setData($attrCode, $valuesIds);
$product->getResource()->saveAttribute($product, $attrCode);

Answer 2

As others have mentioned, the problem is that you go into an infinite loop if you save the product again in the save_after event.

1. you should use the save_before event
2. Don't load() the product again, $product already contains all data
3. Don't save() as the data you set on $product will be saved after the event has finished

So the code for your new observer looks like this:

public function setFilterCategoryBeforeSave(Varien_Event_Observer $observer)
{
 $observer->getProduct()->setData('filter_category','51,52');
}

That's all.

Answer 3

You can filter multiple select using finset. Below is a small example of how filter it

$collection = $this->getCollection()
 ->addAttributeToSelect('*')
 ->addAttributeToFilter('visibility', $visibility)
 ->addAttributeToFilter('status', Mage_Catalog_Model_Product_Status::STATUS_ENABLED)
 ->addAttributeToFilter($attribute,array('finset'=>array_search($selection,$valueId)))
 ->setPageSize($limit)
 ->load();
 Mage::getSingleton('cataloginventory/stock')->addInStockFilterToCollection($collection); 

here $selection is the value of multiple select attribute to be filtered

• Netorica: I don't understand this... please explain further so that your answer can solve my problem
• Dexter: from what i understand from your question you need to filter product by labels in multiple select right ??
• Netorica: no I am not filtering.. I am updating a product
• Dexter: can you tell me what exactly you are doing ?