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

Question

If have a multiselect attribute and want to set the selection on a product.

$selectedOptions = "red,green,blue";
$product->..... // # what to do?

How can I do that?

Answer 1

Multiselect attributes can be set as a comma separated list (or also an array) containing the attribute value ids.

So first we have to convert the actual values to Magento's internal ids.

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

Answer 2

Modify last line of the above code

$product->save();

with

$product->getResource()->saveAttribute($product, $attrCode);

It works