Custom plugin route in WordPress

2 comments

1. You need to do three important things:

   1. Create a custom rewrite rule to turn parts of the URI into values passed to index.php.
   2. Add myroute and myargument to WordPress’s query variables whitelist, so that WordPress doesn’t just ignore them when they appear in a query string.
   3. Flush the rewrite rules.

   Firstly, I’m going to recommend that instead of http://www.example.org/myroute/myargument, you settle on some kind of special prefix or suffix to denote when the URI should be considered one of these special ‘routes’. For the the sake of this example, I’ve chosen the prefix api, so that it would be http://www.example.org/api/myroute/myargument. I chose api because when I did something RESTful, like what you seem to be working on, it was for an API.

   The Code

   add_filter( 'rewrite_rules_array', 'my_insert_rewrite_rules' );
   add_filter( 'query_vars', 'my_insert_query_vars' );
   add_action( 'wp_loaded', 'my_flush_rules' );
   
   // flush_rules() if our rules are not yet included
   function my_flush_rules() {
       $rules = get_option( 'rewrite_rules' );
   
       if ( ! isset( $rules['api/(.*?)/(.+?)'] ) ) {
           global $wp_rewrite;
           $wp_rewrite->flush_rules();
       }
   }
   
   // Adding a new rule
   function my_insert_rewrite_rules( $rules ) {
       $newrules = array();
       $newrules['api/(.*?)/(.+?)'] = 'index.php?myroute=$matches[1]&myargument=$matches[2]';
       return $newrules + $rules;
   }
   
   // Adding the id var so that WP recognizes it
   function my_insert_query_vars( $vars ) {
       array_push( $vars, 'myroute', 'myargument' );
       return $vars;
   }
   

   Quick Breakdown

   It’s all fairly straight forward. The regex pattern is added to a list of all the rewrite rules in WordPress, and your custom pattern is at the top of the list. When the pattern is matched, WordPress will stop looking through the list of rewrite rules, and use the regex’s captured values in place of the references ($matches[1] and $matches[2]) in the query string passed to index.php.

   Adding the query variables myroute and myargument to the whitelist just makes WordPress pay attention to them rather than discarding them.

   Alternative way of ‘namespacing’ your custom route

   If you wanted to avoid using /api/ as a prefix, you could use a query string variable/field instead. To do something like that, you would change the regex to something like (.*?)/(.+?)\?api=1 and then add api as an additional parameter to the array_push() call made in my_insert_query_vars().

   That would change the custom route so that it triggers any time api=1 is the first element of the query string, e.g. it would trigger for http://example.com/anytext/anytext?api=1.

   Ignore the use of the term ‘namespacing’ – just used it for brevity.

   If you don’t ‘namespace’ with either a prefix or a suffix, you will end up with colliding URI patterns. This is because WordPress will have no way to distinguish your custom pattern from one intended to be a post or page. How would WordPress know that myroute is not a taxonomy, term, or a parent page?

   Hope this helps.

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2. To expand a bit on what eddiemoya did above:

   Like the original poster of this question I wanted to create a custom rewrite, and also deliver a custom template for that rewrite page. The code from edditmoya got me started in the right direction, and I added an extra function to serve up my custom template when the page is accessed.

   The custom template could be located anywhere, in my case it is stored in the plugin directory.

   I also only wanted to check if the rewrite rules needed to be flushed during plugin activation, so I put that on a register_activation_hook

   See below for the full example of what I did:

   UPDATED simplified based on advice from milo

   class Your_Class
   {
   
       public function init()
       {
           add_filter( 'template_include', array( $this, 'include_template' ) );
           add_filter( 'init', array( $this, 'rewrite_rules' ) );
       }
   
       public function include_template( $template )
       {
           //try and get the query var we registered in our query_vars() function
           $account_page = get_query_var( 'account_page' );
   
           //if the query var has data, we must be on the right page, load our custom template
           if ( $account_page ) {
               return PATH_TO_PLUGIN_TEMPLATES_DIR . 'register.php';
           }
   
           return $template;
       }
   
       public function flush_rules()
       {
           $this->rewrite_rules();
   
           flush_rewrite_rules();
       }
   
       public function rewrite_rules()
       {
           add_rewrite_rule( 'account/(.+?)/?$', 'index.php?account_page=$matches[1]', 'top');
           add_rewrite_tag( '%account_page%', '([^&]+)' );
       }
   
   }
   
   add_action( 'plugins_loaded', array( new Your_Class, 'init' ) );
   
   // One time activation functions
   register_activation_hook( PATH_TO_PLUGIN_FILE, array( new Your_Class, 'flush_rules' ) );
   

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