Taxonomy Terms in Permalink

gistfile1.php

<?php

/*
Plugin Name: Enhance Insurance - Taxonomy Term In Permalink
Plugin URI: http://www.webdevstudios.com
Description: Add CPT taxonomy terms to permalink
Version: 1.0.0
Author: WebDevStudios
Author URI: http://www.webdevstudios.com
License: GPLv2
Text Domain: enhanceins
*/

add_action( 'init', 'enhanceins_tax_to_permalink' );
function enhanceins_tax_to_permalink() {
    $enhanceins_taxonomy_permalinks = new Add_Taxonomy_To_Post_Permalinks( array( 'states', 'insurance-levels' ) );
}

add_rewrite_rule( "([^/]+)/car-insurance-([^/]+)/?$", 'index.php?post_type=YOURCPT&state=$matches[1]&city=$matches[2]&vertical=car-insurance', 'top' );

/**
 * A helper class for registering and handling a custom rewrite tag for a custom taxonomy. Modified version from Viper0007Bond
 *
 * @version 1.0.0
 */
class Add_Taxonomy_To_Post_Permalinks {
    /**
     * Stores the taxonomy slug that this class will be handling. Don't edit this.
     *
     * @since 1.0.0
     * @var array
     */
    public $taxonomy_first;

    /**
     * Stores the taxonomy slug that this class will be handling. Don't edit this.
     *
     * @since 1.0.0
     * @var array
     */
    public $taxonomy_second;

    /**
     * Stores the rewrite tag complete with percentage signs. Don't edit this.
     *
     * @since 1.0.0
     * @var string
     */
    public $rewrite_tag_first;

    /**
     * Stores the rewrite tag complete with percentage signs. Don't edit this.
     *
     * @since 1.0.0
     * @var string
     */
    public $rewrite_tag_second;

    /**
     * Initializes the class by calling Add_Taxonomy_To_Post_Permalinks::register()
     * as well as registering a filter that runs in get_permalink().
     *
     * @since 1.0.0
     *
     * @param string $taxonomy A taxonomy slug. Use the same one that you used with register_taxonomy().
     * @return array $optional_args Optional configuration parameters. See Add_Taxonomy_To_Post_Permalinks::register().
     */
    function __construct( $taxonomy, $optional_args = array() ) {
        if ( ! $this->register( $taxonomy, $optional_args ) )
            return;

        // Normal posts
        add_filter( 'post_link', array( &$this, 'filter_post_link' ), 10, 2 );

        // Custom post types
        add_filter( 'post_type_link', array( &$this, 'filter_post_link' ), 10, 2 );
    }

    /**
     * Registers the rewrite tag using add_rewrite_tag().
     *
     * Can accept an array of optional parameters:
     *
     * * tagname: The rewrite tag to use (no percentage signs). Defaults to the taxonomy slug.
     * * regex: What regex to use to validate the value of the tag. Defaults to anything but a forward slash.
     *
     * @since 1.0.0
     *
     * @param string $taxonomy A taxonomy slug. Use the same one that you used with register_taxonomy().
     * @return array $optional_args Optional configuration parameters. See function description.
     */
    public function register( $taxonomy, $optional_args = array() ) {

    	if ( !is_array( $taxonomy ) ) {
    		return false;
    	}

		foreach( $taxonomy as $tax ) {
	        if ( ! taxonomy_exists( $tax ) )
	            return false;
		}

        $this->taxonomy_first = $taxonomy[0];
        $this->taxonomy_second = $taxonomy[1];

        $this->rewrite_tag_first = ( ! empty( $optional_args['tagname'] ) ) ? $optional_args['tagname'] : $this->taxonomy_first;
        $this->rewrite_tag_first = '%' . $this->rewrite_tag_first . '%';

        $this->rewrite_tag_second = ( ! empty( $optional_args['tagname'] ) ) ? $optional_args['tagname'] : $this->taxonomy_second;
        $this->rewrite_tag_second = '%' . $this->rewrite_tag_second . '%';

        $rewrite_tag_regex = ( ! empty( $optional_args['regex'] ) ) ? $optional_args['regex'] : '([^/]+)';

        // See http://codex.wordpress.org/Rewrite_API/add_rewrite_tag
        add_rewrite_tag( $this->rewrite_tag_first, $rewrite_tag_regex );
        add_rewrite_tag( $this->rewrite_tag_second, $rewrite_tag_regex );

        return true;
    }

    /**
     * Filters a post permalink to replace the tag placeholder with the first
     * used term from the taxonomy in question.
     *
     * @since 1.0.0
     *
     * @param string $permalink The existing permalink URL.
     * @return object $post The post object that this permalink belongs to.
     */
    public function filter_post_link( $permalink, $post ) {
        //TODO: find a way to limit to just city_vertical post type

        // Abort early if the placeholder rewrite tag isn't in the generated URL
        if ( false === strpos( $permalink, $this->rewrite_tag_first ) && false === strpos( $permalink, $this->rewrite_tag_second ) )
            return $permalink;

        // Get the custom taxonomy terms in use by this post
        $state = get_the_terms( $post->ID, $this->taxonomy_first );
        $level = get_the_terms( $post->ID, $this->taxonomy_second );

        // If no terms are assigned to this post, use the taxonomy slug instead (can't leave the placeholder there)
        if ( empty( $state ) || empty( $level ) ) {
            $permalink = str_replace( $this->rewrite_tag_first, $this->taxonomy_first, $permalink );
            $permalink = str_replace( $this->rewrite_tag_second, $this->taxonomy_second, $permalink );
        }

        // Replace the placeholder rewrite tag with the first term's slug
        else {
            $first_term_first = array_shift( $state );
            $first_term_second = array_shift( $level );
            $permalink = str_replace( $this->rewrite_tag_first, $first_term_first->slug, $permalink );
            $permalink = str_replace( $this->rewrite_tag_second, $first_term_second->slug, $permalink );
        }

        return $permalink;
    }
}