Safe way to get the post ID in the_title()

Question

Is there a safe way to get the post ID inside the_title()?

add_filter('the_title', "change_post_title");

function change_post_title($title){

}

I tried using global $post and get_the_ID(), but this won't work in some cases (e.g. on a single page where the_title() is being called inside the navigation to link to the next post. global $post and get_the_ID() will reference the single post instead of the post that is being linked to.)

With get_page_by_title() I'd have to spawn multiple queries to cover all post types.

Do I have to fall back to a custom query?

Answer 1

Some filters in Wordpress are just not user friendly and does not always quite do what one wants to.

the_title filter will apply changes to all instances of get_the_title() (which is used by the_title()). So widget titles, related posts titles and post link titles are all changed, which is a problem when you just need to target the main post on a single page for instance

I have recently bumped into this post by Josh Levinson on his blog while having the same issue. He suggested to make use of the loop_start action where you check whether or not you are in the main query, and if you are, apply your the_title filter. If the query is not the main query, simply remove the filter

I have made a few changes to the original code. Just a note, you need php 5.3+ as closures was only introduced in php 5.3

add_action('loop_start', function ($q)
{
    if($q->is_main_query()){
        add_filter( 'the_title', 'modified_post_title', 10, 2);
    }else{
        remove_filter('the_title','modified_post_title', 10, 2);
    }
});
function modified_post_title($title)
{
    global $post;
    ?><pre><?php var_dump($post->ID); ?></pre><?php 
}