Yes, this is optional, you still have the same admin interface as before, this is in addition.

As for PHP, no, the reason to do it in Javascript is so you don't have to go to the database everytime. It works as follows:

All first level categories are loaded when the browser inits.

Clicking on a category will call the database and load that categories subcategories.

You can then close and reopen that part of the tree _without_ going to the database.

Make sense?

Cheers,

Alex

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