WP Router Plugin

WordPress’s rewrite rules and query variables provide a powerful system
for mapping URL strings to collections of posts. Every request is parsed
into query variables and turned into a SQL query via $wp_query->query().

Sometimes, though, you don’t want to display a list of posts. You just want
a URL to map to a callback function, with the output displayed in place of
posts in whatever theme you happen to be using.

That’s where WP Router comes in. It handles all the messy bits of registering
post types, query variables, rewrite rules, etc., and lets you write code to
do what you want it to do. One function call is all it takes to map a
URL to your designated callback function and display the return value in the page.

Created by Flightless

Usage

Creating Routes

• Your plugin should hook into the wp_router_generate_routes action.
  The callback should take one argument, a WP_Router object.

• Register a route and its callback using WP_Router::add_route( $id, $args )

  • $id is a unique string your plugin should use to identify the route

  • $args is an associative array, that sets the following properties for your route.
    Any omitted argument will use the default value.

    • path (required) – A regular expression to match against the request path.
      This corresponds to the array key you would use when creating rewrite rules for WordPress.

    • query_vars – An associative array, with the keys being query vars, and the
      values being explicit strings or integers corresponding to matches in the path regexp.
      Any query variables included here will be automatically registered.

    • title – The title of the page.

    • title_callback – A callback to use for dynamically generating the title.
      Defaults to __(). If NULL, the title argument will be used as-is. if
      page_callback or access_callback returns FALSE, title_callback will not be called.

      title_callback can be either a single callback function or an array specifying 

      callback functions for specific HTTP methods (e.g., GET, POST, PUT, DELETE, etc.).
      If the latter, the default key will be used if no other keys match the current
      request method.

    • title_arguments – An array of query variables whose values will be passed
      as arguments to title_callback. Defaults to the value of title. If an argument
      is not a registered query variable, it will be passed as-is.

    • page_callback (required) – A callback to use for dynamically generating the
      contents of the page. The callback should either echo or return the contents of
      the page (if both, the returned value will be appended to the echoed value). If
      FALSE is returned, nothing will be output, and control of the page contents will
      be handed back to WordPress. The callback will be called during the parse_request
      phase of WordPress’s page load. If access_callback returns FALSE, page_callback
      will not be called.

      page_callback can be either a single callback function or an array specifying 

      callback functions for specific HTTP methods (e.g., GET, POST, PUT, DELETE, etc.).
      If the latter, the default key will be used if no other keys match the current
      request method.

    • page_arguments – An array of query variables whose values will be passed as
      arguments to page_callback. If an argument is not a registered query variable,
      it will be passed as-is.

    • access_callback – A callback to determine if the user has permission to access
      this page. If access_arguments is provided, default is current_user_can, otherwise
      default is TRUE. If the callback returns FALSE, anonymous users are redirected to
      the login page, authenticated users get a 403 error.

      access_callback can be either a single callback function or an array specifying 

      callback functions for specific HTTP methods (e.g., GET, POST, PUT, DELETE, etc.).
      If the latter, the default key will be used if no other keys match the current
      request method.

    • access_arguments – An array of query variables whose values will be passed
      as arguments to access_callback. If an argument is not a registered query variable,
      it will be passed as-is.

    • template – An array of templates that can be used to display the page. If a path
      is absolute, it will be used as-is; relative paths allow for overrides by the theme.
      The string $id will be replaced with the ID of the route. If no template is found,
      fallback templates are (in this order): route-$id.php, route.php, page-$id.php,
      page.php, index.php. If FALSE is given instead of an array, the page contents will
      be printed before calling exit() (you can also accomplish this by printing your output
      and exiting directly from your callback function).

Example:
$router->add_route(‘wp-router-sample’, array(
‘path’ => ‘^wp_router/(.*?)$’,
‘query_vars’ => array(
‘sample_argument’ => 1,
),
‘page_callback’ => array(get_class(), ‘sample_callback’),
‘page_arguments’ => array(‘sample_argument’),
‘access_callback’ => TRUE,
‘title’ => ‘WP Router Sample Page’,
‘template’ => array(‘sample-page.php’, dirname(FILE).DIRECTORY_SEPARATOR.’sample-page.php’)
));

In this example, the path http://example.com/wp_router/my_sample_path/ will call
the function sample_callback in the calling class. The value of the sample_argument
query variable, in this case “my_sample_path”, will be provided as the first and only
argument to the callback function. If the file sample-page.php is found in the theme,
it will be used as the template, otherwise sample-page.php in your plugin directory will
be used (if that’s not found either, fall back to route-wp-router-sample.php, etc.).

Editing Routes

• You can hook into the wp_router_alter_routes action to modify routes created by other plugins. The callback should take one argument, a WP_Router object.

Public API Functions

Creating or changing routes should always occur in the context of the wp_router_generate_routes or wp_router_alter_routes actions, using the WP_Router object supplied to your callback function.

• WP_Router::edit_route( string $id, array $changes ) – update each
  property given in $changes for the route with the given ID. Any properties
  not given in $changes will be left unaltered.
• WP_Router::remove_route( string $id ) – delete the route with the given ID
• WP_Router::get_route( string $id ) – get the WP_Route object for the given ID
• WP_Router::get_url( string $id, array $arguments ) – get the URL to reach the route with the given ID, with the given query variables and their values
• WP_Route::get( string $property ) – get the value of the specified property for
  the WP_Route instance

1. Download and unzip the plugin
2. Upload the WP-Router folder to the /wp-content/plugins/ directory
3. Activate the plugin through the ‘Plugins’ menu in WordPress
4. You should see the sample page at http://example.org/wp_router/sample/. Apart from that, there is no public UI for this plugin. You will not see any changes unless the plugin’s API is called by another active plugin.

0.5

• Filter get_permalink on router pages to point to the requested URI
• Filter post meta for the placeholder page when on a router page to provide a title to WP SEO
• Added wp_router_placeholder_postmeta filter for adding additional meta to the placeholder page

0.4

• Prevent redirect from route pages with the “page” or “paged” query arg

0.3.3

• Prevent redirect from all route pages when %category% is in the permastruct
• Redirect placeholder page to the blog front page
• Fix usage of translation functions

0.3.2

• Make $arguments param optional for WP_Router::get_url() and WP_Router::url()

0.3.1

• Added WP_Router::get_url()
• Added WP_Route::url()

0.3

• Added FALSE option to template parameter to indicate immediate exit()
• Added option to specify different callback functions depending on the HTTP request method
• Verified compatibility with WordPress 3.0
• Added WP_Router::get_url() function

0.2

• Added the template argument

0.1

• Initial version