Is there a Filter that I can use to filter the tags before they are inserted in to the database?

Question

I want to filter the tags before they are inserted into the database. I'm aware of the pre_insert_term filter. But what I need to do is to see all the tags at once. I need to limit the number of tags entered to the database per post. Is there a filter to do this? Or any other method?

Thanks

Answer 1

A good thing - as always - is the Action Reference.

You could count the terms from the $post data on pre_post_update.

Answer 2

What about using wp_set_post_tags() (Codex ref) to modify the number of tags, and then hooking that into save_post or publish_post or wherever, as appropriate?

e.g.

function mytheme_limit_post_tags( $post_id ) {
    // code to count/limit the number of tags
    // then pass the modified list of tags to wp_set_post_tags
    wp_set_post_tags( $post_id, $tags, false );
}
add_action( 'publish_post', 'mytheme_limit_post_tags' );