Specify custom post types by code

functions.php

function my_custom_tpa() {
    $labels = array(
        'name'               => _x( 'TPA', 'tpa' ),
        'singular_name'      => _x( 'TPA', 'tpa' ),
        'add_new'            => _x( 'Add New', 'book' ),
        'add_new_item'       => __( 'Add New TPA' ),
        'edit_item'          => __( 'Edit TPA' ),
        'new_item'           => __( 'New TPA' ),
        'all_items'          => __( 'All TPA' ),
        'view_item'          => __( 'View TPA' ),
        'search_items'       => __( 'Search TPA' ),
        'not_found'          => __( 'No TPA found' ),
        'not_found_in_trash' => __( 'No TPA found in the Trash' ),
        'parent_item_colon'  => '',
        'menu_name'          => 'TPA'
    );
    $args = array(
        'labels'        => $labels,
        'description'   => 'Holds our TPA and product specific data',
        'public'        => true,
        'menu_position' => 8,
        'supports'      => array( 'title', 'editor', 'thumbnail', 'excerpt', 'comments' ),
        'has_archive'   => true,
        'taxonomies'    => 'tpac',
        'publicly_queryable' => true,
        'query_var'     => 'tpa',
        'rewrite'       => false
    );
    register_post_type( 'tpa', $args );


    global $wp_rewrite;
    $wp_rewrite->add_rewrite_tag('%tpa%', '([^/]+)', 'tpa=');

    //the root of the post type, ie mysite.com/movie-reviews/ will be the landing page for the post type
    $permalink_prefix = 'tpa';
    //the permalink structure for the post type that will be appended to the prefix, mysite.com/movie-reviews/2010/11/25/test-movie-review/
    $permalink_structure = '/%tpa%/';

    //we use the WP_Rewrite class to generate all the endpoints WordPress can handle by default.
    $rewrite_rules = $wp_rewrite->generate_rewrite_rules($permalink_prefix.'/'.$permalink_structure, EP_ALL, true, true, true, true, true);


    $rewrite_rules = array_merge($wp_rewrite->generate_rewrite_rules($permalink_prefix), $rewrite_rules);
    $rewrite_rules[$permalink_prefix.'/?$'] = 'index.php?paged=1';
    foreach($rewrite_rules as $regex => $redirect) {
        if(strpos($redirect, 'attachment=') === false) {
            //add the post_type to the rewrite rule
            $redirect .= '&post_type=tpa';
        }

        //turn all of the $1, $2,... variables in the matching regex into $matches[] form
        if(0 < preg_match_all('@\$([0-9])@', $redirect, $matches)) {
            for($i = 0; $i < count($matches[0]); $i++) {
                $redirect = str_replace($matches[0][$i], '$matches['.$matches[1][$i].']', $redirect);
            }
        }
        //add the rewrite rule to wp_rewrite
        $wp_rewrite->add_rule($regex, $redirect, 'top');
    }


    add_filter('post_type_link', 'filter_movie_review_link', 10, 2);
    function filter_movie_review_link($permalink, $post) {
        if(('tpa' == $post->post_type) && '' != $permalink && !in_array($post->post_status, array('draft', 'pending', 'auto-draft')) ) {
            $rewritecode = array(
                '%tpa%'
            );

            $unixtime = strtotime($post->post_date);
            $date = explode(" ",date('Y m d H i s', $unixtime));
            $rewritereplace = array(
                $post->post_name,
            );
            $permalink = str_replace($rewritecode, $rewritereplace, '/tpa/%tpa%/');
            $permalink = user_trailingslashit(home_url($permalink));
        }
        return $permalink;
    }

}
add_action( 'init', 'my_custom_tpa' );