如何排序Varien_Data_Collection的通用实例

Question

In Magento, the Varien_Data_Collection class makes provisions for sorting, but it ultimately leaves the work up to the extending class (usually Varien_Data_Collection_Db) through the load method.

But has anyone already done the work to make a generic instance of Varien_Data_Collection sortable?

By that I mean using some crafty means of PHP's user-sorting functions. Not that I'm lazy, but it seems to be a lot of work to re-invent the wheel if it already exists.

Does anyone have a solution for this?

Answer 1

The class Varien_Data_Collection_Filesystem has some example code for using usort to sort files and directories. If you have a custom collection class which extends Varien_Data_Collection you could implement your own sort functions very much like the filesytem class does. It applies the sort on the collection load method which ultimately has a callback function to usort using a specified sort order ($collection->setOrder('sort_attribute')). As far as I am aware there are no existing methods to do this, mainly because magento does most sorting on db data which can be achieved through the sql which is much better for performance.