Question

I am trying my hand at WordPress plugin development. From all of the getting started examples and tutorials I have seen, it seems as though plugins can do little more than, say, add a “Bookmark This” at the end of a post, add an icon next to external links, or other relatively minor enhancements to existing features.

I would like to develop an extension (might that be the better word?) where a user can go to my-wordpress-site.com/the-extension and access the features of the web application. However, since all extensions must placed within wp-includes/plugins/the-extension, does that mean that is the only way the plugins can be accessed?

How could I design the extension and containing pages to be accessed with a URL like this: my-wordpress-site.com/the-extension?

Answer 1

Here’s an example:

// register your rewrite rule
add_action('init', function(){
  add_rewrite_rule('the-extension$', 'index.php?my_plugin_action=do_stuff', 'top');
});

// register your query variable
add_filter('query_vars', function($vars){
  $vars[] = 'my_plugin_action';
  return $vars;
});

// process request
add_action('parse_request', function($wp){

  // check if this is your request; do nothing if not
  if(!isset($wp->query_vars['my_plugin_action']))
    return;

  // otherwise do your stuff
  printf('Hello Pony. You requested "%s"', $wp->query_vars['my_plugin_action']);
  exit;
});

This will only work after you go to your dashboard > settings > permalinks and click the save button to flush rewrite rules, because WP apparently keeps some kind of cache of all rewrite rules.

Then accessing yourwordpresssite.com/the-extension should display the hello message