[wp-trac] [WordPress Trac] #46635: Improve identifying of non–trivial callbacks in hooks

[WordPress Trac]

#46635: Improve identifying of non–trivial callbacks in hooks
-------------------------+-------------------------------
 Reporter:  Rarst        |       Owner:  (none)
     Type:  enhancement  |      Status:  new
 Priority:  normal       |   Milestone:  Awaiting Review
Component:  General      |     Version:
 Severity:  normal       |  Resolution:
 Keywords:               |     Focuses:  coding-standards
-------------------------+-------------------------------

Comment (by giuseppe.mazzapica):

 > While this would have made sense if it was baked into API ''from the
 start'', I feel it is a weak as an optional addition to a very established
 one. It simply doesn't help the case when developer doesn't add an
 identifier and we are back to square one. We do ''need'' to improve
 removal for current state of API.

 Yes, what I've in mind is a way to override an identifier which, by
 default, would be auto-generated.

 A fictional function that generates the string representation of a
 callback could be like this (I speak PHP better than english):

 {{{#!php
 <?php
 function _wp_serialize_callback( $callback, $identifier = null ) {

   if ( ! is_callable( $callback, true ) ) {
     return '';
   }

   // Dev-provided identifier, just use it
   if ( $identifier ) {
     // should be a string, but who knows
     return maybe_serialize( $identifier );
   }

   // plain function (or static methds in the form "ClassName::methodName")
   if ( is_string( $callback ) ) {
      return $callback;
   }

   if ( $callback instanceof Closure ) {
     // $r = new ReflectionFunction($f); return 'function()@' .
 $r->getFileName();
     return 'function()';
   }

   // invokables
   if ( is_object( $callback ) ) {
     $class = get_class( $callback );
     if ( false !== strpos( $class, '@' ) ) {
       // anonymous class
       $class = 'class';
     }

     return $class . '()';
   }

   // methods
   if ( is_array( $callback ) ) {

      // static methods can be rendered as strings
      if ( is_string( $callback[0] ) ) {
         return $callback[0] . '::' . $callback[1];
      }

      $class = get_class( $callback );
      if ( false !== strpos( $class, '@' ) ) {
        // anonymous class
        $class = 'class';
      }

      return $class . '->' . $callback[1];
   }
 }
 }}}

 With such function in place, `WP_Hook` could keep a map from callbacks
 ''IDs'' (created by `_wp_filter_build_unique_id`) to callback ''string
 representations''.

 If a string representation is passed to `remove_filter`, the callback ID
 can be resolved from that map, and hook can be removed.

 Of course, the map could have multiple IDs for a single string
 representation, and in such case probably all matching hooks should be
 removed.

 With such approach ''at least'' we have something, but in best case
 scenario (which imo should be recommended by WPCS) there's the possibility
 to ''really'' uniquely identify closures.

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/46635#comment:8>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform