CakePHP HABTM relation Data Format
The following is the format for $data that CakePHP expect on your Model->saveAll($data) call, using the example of Article and Tags.
array(
'Article' => array(
//Article data goes here as usual
)
'Tag' => array(
'Tag' => array(
1,
2,
3
)
)
);
Just thought I should note down in case I forget again, like I just did.