Resume Manager - Add meta data to the permalinks

gistfile1.php

<?php

/**
 * Add rewrite tags for the data we want to insert and define the structure of the permalink.
 *
 * You need to go to Settings > Permalinks and save for these rules to be added.
 */
function add_resume_rewrite_rules(){
	add_rewrite_tag( '%resume%', '([^/]+)', 'resume=' );
	add_rewrite_tag( '%candidate_title%', '([^/]+)', 'candidate_title=' );
	add_permastruct( 'resume', 'resumes/%candidate_title%/%resume%', true );
}
add_action( 'init', 'add_resume_rewrite_rules', 11 );

/**
 * Add data to the permalinks
 * @param  string $permalink
 * @param  WP_Post $post
 * @param  bool
 * @return string
 */
function resume_permalinks( $permalink, $post, $leavename ) {
	// Only affect resumes
	if ( $post->post_type !== 'resume' || empty( $permalink ) || in_array( $post->post_status, array( 'draft', 'pending', 'auto-draft' ) ) ) {
		return $permalink;
	}

	// Get the meta data to add to the permalink
	$title = get_post_meta( $post->ID, '_candidate_title', true );

	// We need data, so fallback to this if its empty
	if ( empty( $title ) ) {
		$title = 'candidate';
	}

	// Do the replacement
	$permalink = str_replace( '%candidate_title%', sanitize_title( $title ), $permalink );

	return $permalink;
}
add_filter( 'post_type_link', 'resume_permalinks', 10, 3 );