[FIXED] How to Save HasAndBelongsToMany (habtm) data when empty in CakePHP

Issue

I have a hasAndBelongsToMany association between Node and NodeTag.

My save works great when at least one is selected, but - if there is a previous association, and they try to save with none selected, my habtm table doesn't get updated, since it's not getting anything passed for NodeTag.

(I'm not sure if this is because I'm using javascript and custom buttons, or if the default CakePHP checkboxes do the same thing).

Solution

In my Controller, before the save, I added this:

if(!isset($this->request->data['NodeTag'])) {
    $this->request->data['NodeTag'][0] = array();
}

This makes it so if I wasn't sending any NodeTag data, I now pass an empty array, and it updates the habtm table so that this Node no longer has any rows for NodeTags.

Note: Notice the array structure: ['NodeTag'][0] = array();

Answered By - Dave

Answer Checked By - Marilyn (PHPFixing Volunteer)