Monthly Archives: June 2012

Flush wp_rewrite rules

Wordpress,

As stated on WordPress Codex: Flushing the rewrite rules is an expensive operation. So it’s best to refresh your wp_rewrite rules by not using the init hook.  Austin Passy chooses to Flush your rewrite rules on plugin/theme activation on checking $_GET parameters.  I’ve tried it two different ways.  The first option seemed to work for a while, but my added rule disappeared somehow and began sending requests to a 404 page so I started using the other option.

Option 1:

$custom_permalink_rules_exist = get_option( $this->permalink_rule_option_name );

if( $custom_permalink_rules_exist != "1") {
	add_action( 'init', 'flush_rewrite_rules');
	add_action( 'generate_rewrite_rules', array( &$this, 'add_rewrite_rules' ) );

	update_option( $this->permalink_rule_option_name, '1');
}

Option 2:

/**
	 * Flushing the wp_rewrite rules is an expensive proceedure so check
	 * if the rules exist
	 *
	 * @global object $wp_rewrite
	 */
	function verify_rewrite_rule_exists() {
		global $wp_rewrite;

		if( empty($this->rewrite_rule_key) ||
			!array_key_exists($this->rewrite_rule_key, $wp_rewrite->rules ) ) {
			add_action( 'generate_rewrite_rules', array( &$this, 'add_rewrite_rules' ) );
		}
	}

	function add_rewrite_rules( $wp_rewrite ) {
		global $wp_rewrite;

		$this->rewrite_rule_key = "^{$this->post_type_slug}/([^/]*)/([^/]*)/([^/]*)$";

		// match a custom post_type with a parent and child taxonomy
		$new_rules = array( "^{$this->post_type_slug}/([^/]*)/([^/]*)/([^/]*)$" => "index.php?{$this->post_type_slug}=" . $wp_rewrite->preg_index(3) );

		// match a custom post_type with only one taxonomy; however, will break the archive page for two taxonomies
		//$new_rules = array( "^{$this->post_type_slug}/([^/]*)/([^/]*)$" => "index.php?{$this->post_type_slug}=" . $wp_rewrite->preg_index(2) );

		// Add the new rewrite rule into the top of the global rules array
		$wp_rewrite->rules = $new_rules + $wp_rewrite->rules;

		flush_rewrite_rules();

		return $wp_rewrite->rules;
	}

Custom Post Type redirects to 404 page

Wordpress

This function from dev4press really helped me debug my custom post type redirect to a 404 page.

 

Place this code in your functions.php file:

function dev4press_debug_page_request() {
		global $wp, $template;

		echo '<pre>!-- Request: ';
		echo empty($wp->request) ? "None" : esc_html($wp->request);
		echo ' -->'.PHP_EOL;
		echo '!-- Matched Rewrite Rule: ';
		echo empty($wp->matched_rule) ? None : esc_html($wp->matched_rule);
		echo ' -->'.PHP_EOL;
		echo '!-- Matched Rewrite Query: ';
		echo empty($wp->matched_query) ? "None" : esc_html($wp->matched_query);
		echo ' -->'.PHP_EOL;
		echo '!-- Loaded Template: ';
		echo basename($template);
		echo ' --></pre>'.PHP_EOL;
	}

Place this in your template file:

dev4press_debug_page_request();

echo '<h1>Rewrite Rules</h1>';

global $wp_rewrite;

echo '<pre>';
print_r($wp_rewrite->rules);
echo '</pre>';