有人要我对 Magento layer navigation 做些小修改，我觉得修修补补没有意义，要做就做一系列的修改，于是按我觉得可以改进的方向，列了以下几点。
Add ajax load/change products on page loads or filter changes (TODO)
Add option to show/hide category filter
Add option to show price filter as slidebar (TODO)
Add option to control price accuracy
Add up to 3 sort by’s (TODO)
(Someone already asked for a second sort by)
Add option to show/hide sort by’s (TODO)
Add option to or not to merge sort asc/desc into sort by dropdown (TODO)
Add sort by’s position (TODO)
(Magento native code can control filter attributes’ position, but cannot control sort by attributes’ position)
Add recursive walk-through function to sort by settings for category and its child categories (TODO)