Custom action for WordPress Template Redirect

gistfile1.aw

<?php

/**
 * Determine if given templates exists if they do loads them
 * based on the type of page being displayed.
 *
 * @uses is_single()
 */
if ( ! function_exists( '_zm_template_redirect' ) ) :
function _zm_template_redirect( $params=array()){

    extract( $params );

    if ( is_single() ) {
        if ( file_exists( $params['single'] ) ) {
            load_template( $params['single'] );
            exit();
        }
    } elseif ( is_post_type_archive('bmx-race-event') ) {
        if ( file_exists( $params['archive'] ) ) {
            load_template( $params['archive'] );
            exit();
        }
    } elseif ( is_search() ) {
        if ( file_exists( $params['search'] ) ) {
            load_template( $params['search'] );
            exit;
        }
    } elseif ( is_tax() ) {
        if ( is_array( $params['taxonomy'] ) ) {
            foreach( $params['taxonomy'] as $taxonomy ){
                if ( file_exists( $taxonomy['template'] ) ) {
                    load_template( $taxonomy['template'] );
                    exit;
                }
            }
        }
        if ( file_exists( $params['taxonomy'] ) ) {
            load_template( $params['taxonomy'] );
            exit;
        } else {
            load_template( $params['taxonomy'] );
            exit;
        }
    } else {
        if ( file_exists( $params['default'] ) ) {
            load_template( $params['default'] );
            exit;
        }
    }
}
add_action( 'zm_template_redirect', '_zm_template_redirect', 1 );
endif;