A recent update to the Dynamic Category Products Extension allows you to mass-update all/any product attributes, after a product was placed in the category.

This feature will help / allow you to get your product attributes better set, with more relevant data.

The feature is very easy to use.

Lets say you have a bunch of products that have the word 'black' in the description.

This will be a straight forward rule in Dynamic Catgeory Product:

description based rule

You will result in a list of found products attached to the category.

Using the new feature, you can now also set all those products to have the color black for the color attribute. Just to clarify, you can set ANY attributes for the found products.

In the example I show this done.

one usage case:

You can simply have hidden categories, which is used to ensure newly imported products have all the correct attribute data set, and no longer need to code that to any importer. Save time and effort!

Events fired:

You may have special requirements, so some events are fired upon updates

Two events, one generic, one specific to the attribute code:

Mage::dispatchEvent('dyncatprod_attribute_update' . $this->getAttribute(),
array('product_id' => $_product->getId(),
'values_by_id' => $valuesById,
'store_id' => $updates->getValue()));

array('product_id' => $_product->getId(),
'attribute_code' => $this->getAttribute(),
'values_by_id' => $valuesById,
'store_id' => $updates->getValue()));