wp/wp-includes/plugin.php
changeset 0 d970ebf37754
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     1 <?php
       
     2 /**
       
     3  * The plugin API is located in this file, which allows for creating actions
       
     4  * and filters and hooking functions, and methods. The functions or methods will
       
     5  * then be run when the action or filter is called.
       
     6  *
       
     7  * The API callback examples reference functions, but can be methods of classes.
       
     8  * To hook methods, you'll need to pass an array one of two ways.
       
     9  *
       
    10  * Any of the syntaxes explained in the PHP documentation for the
       
    11  * {@link http://us2.php.net/manual/en/language.pseudo-types.php#language.types.callback 'callback'}
       
    12  * type are valid.
       
    13  *
       
    14  * Also see the {@link http://codex.wordpress.org/Plugin_API Plugin API} for
       
    15  * more information and examples on how to use a lot of these functions.
       
    16  *
       
    17  * @package WordPress
       
    18  * @subpackage Plugin
       
    19  * @since 1.5
       
    20  */
       
    21 
       
    22 // Initialize the filter globals.
       
    23 global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
       
    24 
       
    25 if ( ! isset( $wp_filter ) )
       
    26 	$wp_filter = array();
       
    27 
       
    28 if ( ! isset( $wp_actions ) )
       
    29 	$wp_actions = array();
       
    30 
       
    31 if ( ! isset( $merged_filters ) )
       
    32 	$merged_filters = array();
       
    33 
       
    34 if ( ! isset( $wp_current_filter ) )
       
    35 	$wp_current_filter = array();
       
    36 
       
    37 /**
       
    38  * Hooks a function or method to a specific filter action.
       
    39  *
       
    40  * WordPress offers filter hooks to allow plugins to modify
       
    41  * various types of internal data at runtime.
       
    42  *
       
    43  * A plugin can modify data by binding a callback to a filter hook. When the filter
       
    44  * is later applied, each bound callback is run in order of priority, and given
       
    45  * the opportunity to modify a value by returning a new value.
       
    46  *
       
    47  * The following example shows how a callback function is bound to a filter hook.
       
    48  * Note that $example is passed to the callback, (maybe) modified, then returned:
       
    49  *
       
    50  * <code>
       
    51  * function example_callback( $example ) {
       
    52  * 	// Maybe modify $example in some way
       
    53  * 	return $example;
       
    54  * }
       
    55  * add_filter( 'example_filter', 'example_callback' );
       
    56  * </code>
       
    57  *
       
    58  * Since WordPress 1.5.1, bound callbacks can take as many arguments as are
       
    59  * passed as parameters in the corresponding apply_filters() call. The $accepted_args
       
    60  * parameter allows for calling functions only when the number of args match.
       
    61  *
       
    62  * <strong>Note:</strong> the function will return true whether or not the callback
       
    63  * is valid. It is up to you to take care. This is done for optimization purposes,
       
    64  * so everything is as quick as possible.
       
    65  *
       
    66  * @package WordPress
       
    67  * @subpackage Plugin
       
    68  *
       
    69  * @global array $wp_filter      A multidimensional array of all hooks and the callbacks hooked to them.
       
    70  * @global array $merged_filters Tracks the tags that need to be merged for later. If the hook is added, it doesn't need to run through that process.
       
    71  *
       
    72  * @since 0.71
       
    73  *
       
    74  * @param string   $tag             The name of the filter to hook the $function_to_add callback to.
       
    75  * @param callback $function_to_add The callback to be run when the filter is applied.
       
    76  * @param int      $priority        (optional) The order in which the functions associated with a particular action are executed. Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action.
       
    77  *                                  Default 10.
       
    78  * @param int      $accepted_args   (optional) The number of arguments the function accepts.
       
    79  *                                  Default 1.
       
    80  * @return boolean true
       
    81  */
       
    82 function add_filter( $tag, $function_to_add, $priority = 10, $accepted_args = 1 ) {
       
    83 	global $wp_filter, $merged_filters;
       
    84 
       
    85 	$idx = _wp_filter_build_unique_id($tag, $function_to_add, $priority);
       
    86 	$wp_filter[$tag][$priority][$idx] = array('function' => $function_to_add, 'accepted_args' => $accepted_args);
       
    87 	unset( $merged_filters[ $tag ] );
       
    88 	return true;
       
    89 }
       
    90 
       
    91 /**
       
    92  * Check if any filter has been registered for a hook.
       
    93  *
       
    94  * @package WordPress
       
    95  * @subpackage Plugin
       
    96  * @since 2.5
       
    97  * @global array $wp_filter Stores all of the filters
       
    98  *
       
    99  * @param string $tag The name of the filter hook.
       
   100  * @param callback $function_to_check optional.
       
   101  * @return mixed If $function_to_check is omitted, returns boolean for whether the hook has anything registered.
       
   102  * 	When checking a specific function, the priority of that hook is returned, or false if the function is not attached.
       
   103  * 	When using the $function_to_check argument, this function may return a non-boolean value that evaluates to false
       
   104  * 	(e.g.) 0, so use the === operator for testing the return value.
       
   105  */
       
   106 function has_filter($tag, $function_to_check = false) {
       
   107 	global $wp_filter;
       
   108 
       
   109 	$has = !empty($wp_filter[$tag]);
       
   110 	if ( false === $function_to_check || false == $has )
       
   111 		return $has;
       
   112 
       
   113 	if ( !$idx = _wp_filter_build_unique_id($tag, $function_to_check, false) )
       
   114 		return false;
       
   115 
       
   116 	foreach ( (array) array_keys($wp_filter[$tag]) as $priority ) {
       
   117 		if ( isset($wp_filter[$tag][$priority][$idx]) )
       
   118 			return $priority;
       
   119 	}
       
   120 
       
   121 	return false;
       
   122 }
       
   123 
       
   124 /**
       
   125  * Call the functions added to a filter hook.
       
   126  *
       
   127  * The callback functions attached to filter hook $tag are invoked by calling
       
   128  * this function. This function can be used to create a new filter hook by
       
   129  * simply calling this function with the name of the new hook specified using
       
   130  * the $tag parameter.
       
   131  *
       
   132  * The function allows for additional arguments to be added and passed to hooks.
       
   133  * <code>
       
   134  * // Our filter callback function
       
   135  * function example_callback( $string, $arg1, $arg2 ) {
       
   136  *	// (maybe) modify $string
       
   137  *	return $string;
       
   138  * }
       
   139  * add_filter( 'example_filter', 'example_callback', 10, 3 );
       
   140  *
       
   141  * // Apply the filters by calling the 'example_callback' function we
       
   142  * // "hooked" to 'example_filter' using the add_filter() function above.
       
   143  * // - 'example_filter' is the filter hook $tag
       
   144  * // - 'filter me' is the value being filtered
       
   145  * // - $arg1 and $arg2 are the additional arguments passed to the callback.
       
   146  * $value = apply_filters( 'example_filter', 'filter me', $arg1, $arg2 );
       
   147  * </code>
       
   148  *
       
   149  * @package WordPress
       
   150  * @subpackage Plugin
       
   151  *
       
   152  * @global array $wp_filter         Stores all of the filters
       
   153  * @global array $merged_filters    Merges the filter hooks using this function.
       
   154  * @global array $wp_current_filter stores the list of current filters with the current one last
       
   155  *
       
   156  * @since 0.71
       
   157  *
       
   158  * @param string $tag  The name of the filter hook.
       
   159  * @param mixed $value The value on which the filters hooked to <tt>$tag</tt> are applied on.
       
   160  * @param mixed $var   Additional variables passed to the functions hooked to <tt>$tag</tt>.
       
   161  * @return mixed The filtered value after all hooked functions are applied to it.
       
   162  */
       
   163 function apply_filters( $tag, $value ) {
       
   164 	global $wp_filter, $merged_filters, $wp_current_filter;
       
   165 
       
   166 	$args = array();
       
   167 
       
   168 	// Do 'all' actions first
       
   169 	if ( isset($wp_filter['all']) ) {
       
   170 		$wp_current_filter[] = $tag;
       
   171 		$args = func_get_args();
       
   172 		_wp_call_all_hook($args);
       
   173 	}
       
   174 
       
   175 	if ( !isset($wp_filter[$tag]) ) {
       
   176 		if ( isset($wp_filter['all']) )
       
   177 			array_pop($wp_current_filter);
       
   178 		return $value;
       
   179 	}
       
   180 
       
   181 	if ( !isset($wp_filter['all']) )
       
   182 		$wp_current_filter[] = $tag;
       
   183 
       
   184 	// Sort
       
   185 	if ( !isset( $merged_filters[ $tag ] ) ) {
       
   186 		ksort($wp_filter[$tag]);
       
   187 		$merged_filters[ $tag ] = true;
       
   188 	}
       
   189 
       
   190 	reset( $wp_filter[ $tag ] );
       
   191 
       
   192 	if ( empty($args) )
       
   193 		$args = func_get_args();
       
   194 
       
   195 	do {
       
   196 		foreach( (array) current($wp_filter[$tag]) as $the_ )
       
   197 			if ( !is_null($the_['function']) ){
       
   198 				$args[1] = $value;
       
   199 				$value = call_user_func_array($the_['function'], array_slice($args, 1, (int) $the_['accepted_args']));
       
   200 			}
       
   201 
       
   202 	} while ( next($wp_filter[$tag]) !== false );
       
   203 
       
   204 	array_pop( $wp_current_filter );
       
   205 
       
   206 	return $value;
       
   207 }
       
   208 
       
   209 /**
       
   210  * Execute functions hooked on a specific filter hook, specifying arguments in an array.
       
   211  *
       
   212  * @see apply_filters() This function is identical, but the arguments passed to the
       
   213  * functions hooked to <tt>$tag</tt> are supplied using an array.
       
   214  *
       
   215  * @package WordPress
       
   216  * @subpackage Plugin
       
   217  * @since 3.0.0
       
   218  * @global array $wp_filter Stores all of the filters
       
   219  * @global array $merged_filters Merges the filter hooks using this function.
       
   220  * @global array $wp_current_filter stores the list of current filters with the current one last
       
   221  *
       
   222  * @param string $tag The name of the filter hook.
       
   223  * @param array $args The arguments supplied to the functions hooked to <tt>$tag</tt>
       
   224  * @return mixed The filtered value after all hooked functions are applied to it.
       
   225  */
       
   226 function apply_filters_ref_array($tag, $args) {
       
   227 	global $wp_filter, $merged_filters, $wp_current_filter;
       
   228 
       
   229 	// Do 'all' actions first
       
   230 	if ( isset($wp_filter['all']) ) {
       
   231 		$wp_current_filter[] = $tag;
       
   232 		$all_args = func_get_args();
       
   233 		_wp_call_all_hook($all_args);
       
   234 	}
       
   235 
       
   236 	if ( !isset($wp_filter[$tag]) ) {
       
   237 		if ( isset($wp_filter['all']) )
       
   238 			array_pop($wp_current_filter);
       
   239 		return $args[0];
       
   240 	}
       
   241 
       
   242 	if ( !isset($wp_filter['all']) )
       
   243 		$wp_current_filter[] = $tag;
       
   244 
       
   245 	// Sort
       
   246 	if ( !isset( $merged_filters[ $tag ] ) ) {
       
   247 		ksort($wp_filter[$tag]);
       
   248 		$merged_filters[ $tag ] = true;
       
   249 	}
       
   250 
       
   251 	reset( $wp_filter[ $tag ] );
       
   252 
       
   253 	do {
       
   254 		foreach( (array) current($wp_filter[$tag]) as $the_ )
       
   255 			if ( !is_null($the_['function']) )
       
   256 				$args[0] = call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
       
   257 
       
   258 	} while ( next($wp_filter[$tag]) !== false );
       
   259 
       
   260 	array_pop( $wp_current_filter );
       
   261 
       
   262 	return $args[0];
       
   263 }
       
   264 
       
   265 /**
       
   266  * Removes a function from a specified filter hook.
       
   267  *
       
   268  * This function removes a function attached to a specified filter hook. This
       
   269  * method can be used to remove default functions attached to a specific filter
       
   270  * hook and possibly replace them with a substitute.
       
   271  *
       
   272  * To remove a hook, the $function_to_remove and $priority arguments must match
       
   273  * when the hook was added. This goes for both filters and actions. No warning
       
   274  * will be given on removal failure.
       
   275  *
       
   276  * @package WordPress
       
   277  * @subpackage Plugin
       
   278  * @since 1.2
       
   279  *
       
   280  * @param string $tag The filter hook to which the function to be removed is hooked.
       
   281  * @param callback $function_to_remove The name of the function which should be removed.
       
   282  * @param int $priority optional. The priority of the function (default: 10).
       
   283  * @param int $accepted_args optional. The number of arguments the function accepts (default: 1).
       
   284  * @return boolean Whether the function existed before it was removed.
       
   285  */
       
   286 function remove_filter( $tag, $function_to_remove, $priority = 10 ) {
       
   287 	$function_to_remove = _wp_filter_build_unique_id($tag, $function_to_remove, $priority);
       
   288 
       
   289 	$r = isset($GLOBALS['wp_filter'][$tag][$priority][$function_to_remove]);
       
   290 
       
   291 	if ( true === $r) {
       
   292 		unset($GLOBALS['wp_filter'][$tag][$priority][$function_to_remove]);
       
   293 		if ( empty($GLOBALS['wp_filter'][$tag][$priority]) )
       
   294 			unset($GLOBALS['wp_filter'][$tag][$priority]);
       
   295 		unset($GLOBALS['merged_filters'][$tag]);
       
   296 	}
       
   297 
       
   298 	return $r;
       
   299 }
       
   300 
       
   301 /**
       
   302  * Remove all of the hooks from a filter.
       
   303  *
       
   304  * @since 2.7
       
   305  *
       
   306  * @param string $tag The filter to remove hooks from.
       
   307  * @param int $priority The priority number to remove.
       
   308  * @return bool True when finished.
       
   309  */
       
   310 function remove_all_filters($tag, $priority = false) {
       
   311 	global $wp_filter, $merged_filters;
       
   312 
       
   313 	if( isset($wp_filter[$tag]) ) {
       
   314 		if( false !== $priority && isset($wp_filter[$tag][$priority]) )
       
   315 			unset($wp_filter[$tag][$priority]);
       
   316 		else
       
   317 			unset($wp_filter[$tag]);
       
   318 	}
       
   319 
       
   320 	if( isset($merged_filters[$tag]) )
       
   321 		unset($merged_filters[$tag]);
       
   322 
       
   323 	return true;
       
   324 }
       
   325 
       
   326 /**
       
   327  * Retrieve the name of the current filter or action.
       
   328  *
       
   329  * @package WordPress
       
   330  * @subpackage Plugin
       
   331  * @since 2.5
       
   332  *
       
   333  * @return string Hook name of the current filter or action.
       
   334  */
       
   335 function current_filter() {
       
   336 	global $wp_current_filter;
       
   337 	return end( $wp_current_filter );
       
   338 }
       
   339 
       
   340 /**
       
   341  * Hooks a function on to a specific action.
       
   342  *
       
   343  * Actions are the hooks that the WordPress core launches at specific points
       
   344  * during execution, or when specific events occur. Plugins can specify that
       
   345  * one or more of its PHP functions are executed at these points, using the
       
   346  * Action API.
       
   347  *
       
   348  * @uses add_filter() Adds an action. Parameter list and functionality are the same.
       
   349  *
       
   350  * @package WordPress
       
   351  * @subpackage Plugin
       
   352  * @since 1.2
       
   353  *
       
   354  * @param string $tag The name of the action to which the $function_to_add is hooked.
       
   355  * @param callback $function_to_add The name of the function you wish to be called.
       
   356  * @param int $priority optional. Used to specify the order in which the functions associated with a particular action are executed (default: 10). Lower numbers correspond with earlier execution, and functions with the same priority are executed in the order in which they were added to the action.
       
   357  * @param int $accepted_args optional. The number of arguments the function accept (default 1).
       
   358  */
       
   359 function add_action($tag, $function_to_add, $priority = 10, $accepted_args = 1) {
       
   360 	return add_filter($tag, $function_to_add, $priority, $accepted_args);
       
   361 }
       
   362 
       
   363 /**
       
   364  * Execute functions hooked on a specific action hook.
       
   365  *
       
   366  * This function invokes all functions attached to action hook $tag. It is
       
   367  * possible to create new action hooks by simply calling this function,
       
   368  * specifying the name of the new hook using the <tt>$tag</tt> parameter.
       
   369  *
       
   370  * You can pass extra arguments to the hooks, much like you can with
       
   371  * apply_filters().
       
   372  *
       
   373  * @see apply_filters() This function works similar with the exception that
       
   374  * nothing is returned and only the functions or methods are called.
       
   375  *
       
   376  * @package WordPress
       
   377  * @subpackage Plugin
       
   378  * @since 1.2
       
   379  * @global array $wp_filter Stores all of the filters
       
   380  * @global array $wp_actions Increments the amount of times action was triggered.
       
   381  *
       
   382  * @param string $tag The name of the action to be executed.
       
   383  * @param mixed $arg,... Optional additional arguments which are passed on to the functions hooked to the action.
       
   384  * @return null Will return null if $tag does not exist in $wp_filter array
       
   385  */
       
   386 function do_action($tag, $arg = '') {
       
   387 	global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
       
   388 
       
   389 	if ( ! isset($wp_actions[$tag]) )
       
   390 		$wp_actions[$tag] = 1;
       
   391 	else
       
   392 		++$wp_actions[$tag];
       
   393 
       
   394 	// Do 'all' actions first
       
   395 	if ( isset($wp_filter['all']) ) {
       
   396 		$wp_current_filter[] = $tag;
       
   397 		$all_args = func_get_args();
       
   398 		_wp_call_all_hook($all_args);
       
   399 	}
       
   400 
       
   401 	if ( !isset($wp_filter[$tag]) ) {
       
   402 		if ( isset($wp_filter['all']) )
       
   403 			array_pop($wp_current_filter);
       
   404 		return;
       
   405 	}
       
   406 
       
   407 	if ( !isset($wp_filter['all']) )
       
   408 		$wp_current_filter[] = $tag;
       
   409 
       
   410 	$args = array();
       
   411 	if ( is_array($arg) && 1 == count($arg) && isset($arg[0]) && is_object($arg[0]) ) // array(&$this)
       
   412 		$args[] =& $arg[0];
       
   413 	else
       
   414 		$args[] = $arg;
       
   415 	for ( $a = 2; $a < func_num_args(); $a++ )
       
   416 		$args[] = func_get_arg($a);
       
   417 
       
   418 	// Sort
       
   419 	if ( !isset( $merged_filters[ $tag ] ) ) {
       
   420 		ksort($wp_filter[$tag]);
       
   421 		$merged_filters[ $tag ] = true;
       
   422 	}
       
   423 
       
   424 	reset( $wp_filter[ $tag ] );
       
   425 
       
   426 	do {
       
   427 		foreach ( (array) current($wp_filter[$tag]) as $the_ )
       
   428 			if ( !is_null($the_['function']) )
       
   429 				call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
       
   430 
       
   431 	} while ( next($wp_filter[$tag]) !== false );
       
   432 
       
   433 	array_pop($wp_current_filter);
       
   434 }
       
   435 
       
   436 /**
       
   437  * Retrieve the number of times an action is fired.
       
   438  *
       
   439  * @package WordPress
       
   440  * @subpackage Plugin
       
   441  * @since 2.1
       
   442  * @global array $wp_actions Increments the amount of times action was triggered.
       
   443  *
       
   444  * @param string $tag The name of the action hook.
       
   445  * @return int The number of times action hook <tt>$tag</tt> is fired
       
   446  */
       
   447 function did_action($tag) {
       
   448 	global $wp_actions;
       
   449 
       
   450 	if ( ! isset( $wp_actions[ $tag ] ) )
       
   451 		return 0;
       
   452 
       
   453 	return $wp_actions[$tag];
       
   454 }
       
   455 
       
   456 /**
       
   457  * Execute functions hooked on a specific action hook, specifying arguments in an array.
       
   458  *
       
   459  * @see do_action() This function is identical, but the arguments passed to the
       
   460  * functions hooked to <tt>$tag</tt> are supplied using an array.
       
   461  *
       
   462  * @package WordPress
       
   463  * @subpackage Plugin
       
   464  * @since 2.1
       
   465  * @global array $wp_filter Stores all of the filters
       
   466  * @global array $wp_actions Increments the amount of times action was triggered.
       
   467  *
       
   468  * @param string $tag The name of the action to be executed.
       
   469  * @param array $args The arguments supplied to the functions hooked to <tt>$tag</tt>
       
   470  * @return null Will return null if $tag does not exist in $wp_filter array
       
   471  */
       
   472 function do_action_ref_array($tag, $args) {
       
   473 	global $wp_filter, $wp_actions, $merged_filters, $wp_current_filter;
       
   474 
       
   475 	if ( ! isset($wp_actions[$tag]) )
       
   476 		$wp_actions[$tag] = 1;
       
   477 	else
       
   478 		++$wp_actions[$tag];
       
   479 
       
   480 	// Do 'all' actions first
       
   481 	if ( isset($wp_filter['all']) ) {
       
   482 		$wp_current_filter[] = $tag;
       
   483 		$all_args = func_get_args();
       
   484 		_wp_call_all_hook($all_args);
       
   485 	}
       
   486 
       
   487 	if ( !isset($wp_filter[$tag]) ) {
       
   488 		if ( isset($wp_filter['all']) )
       
   489 			array_pop($wp_current_filter);
       
   490 		return;
       
   491 	}
       
   492 
       
   493 	if ( !isset($wp_filter['all']) )
       
   494 		$wp_current_filter[] = $tag;
       
   495 
       
   496 	// Sort
       
   497 	if ( !isset( $merged_filters[ $tag ] ) ) {
       
   498 		ksort($wp_filter[$tag]);
       
   499 		$merged_filters[ $tag ] = true;
       
   500 	}
       
   501 
       
   502 	reset( $wp_filter[ $tag ] );
       
   503 
       
   504 	do {
       
   505 		foreach( (array) current($wp_filter[$tag]) as $the_ )
       
   506 			if ( !is_null($the_['function']) )
       
   507 				call_user_func_array($the_['function'], array_slice($args, 0, (int) $the_['accepted_args']));
       
   508 
       
   509 	} while ( next($wp_filter[$tag]) !== false );
       
   510 
       
   511 	array_pop($wp_current_filter);
       
   512 }
       
   513 
       
   514 /**
       
   515  * Check if any action has been registered for a hook.
       
   516  *
       
   517  * @package WordPress
       
   518  * @subpackage Plugin
       
   519  * @since 2.5
       
   520  * @see has_filter() has_action() is an alias of has_filter().
       
   521  *
       
   522  * @param string $tag The name of the action hook.
       
   523  * @param callback $function_to_check optional.
       
   524  * @return mixed If $function_to_check is omitted, returns boolean for whether the hook has anything registered.
       
   525  * 	When checking a specific function, the priority of that hook is returned, or false if the function is not attached.
       
   526  * 	When using the $function_to_check argument, this function may return a non-boolean value that evaluates to false
       
   527  * 	(e.g.) 0, so use the === operator for testing the return value.
       
   528  */
       
   529 function has_action($tag, $function_to_check = false) {
       
   530 	return has_filter($tag, $function_to_check);
       
   531 }
       
   532 
       
   533 /**
       
   534  * Removes a function from a specified action hook.
       
   535  *
       
   536  * This function removes a function attached to a specified action hook. This
       
   537  * method can be used to remove default functions attached to a specific filter
       
   538  * hook and possibly replace them with a substitute.
       
   539  *
       
   540  * @package WordPress
       
   541  * @subpackage Plugin
       
   542  * @since 1.2
       
   543  *
       
   544  * @param string $tag The action hook to which the function to be removed is hooked.
       
   545  * @param callback $function_to_remove The name of the function which should be removed.
       
   546  * @param int $priority optional The priority of the function (default: 10).
       
   547  * @return boolean Whether the function is removed.
       
   548  */
       
   549 function remove_action( $tag, $function_to_remove, $priority = 10 ) {
       
   550 	return remove_filter( $tag, $function_to_remove, $priority );
       
   551 }
       
   552 
       
   553 /**
       
   554  * Remove all of the hooks from an action.
       
   555  *
       
   556  * @since 2.7
       
   557  *
       
   558  * @param string $tag The action to remove hooks from.
       
   559  * @param int $priority The priority number to remove them from.
       
   560  * @return bool True when finished.
       
   561  */
       
   562 function remove_all_actions($tag, $priority = false) {
       
   563 	return remove_all_filters($tag, $priority);
       
   564 }
       
   565 
       
   566 //
       
   567 // Functions for handling plugins.
       
   568 //
       
   569 
       
   570 /**
       
   571  * Gets the basename of a plugin.
       
   572  *
       
   573  * This method extracts the name of a plugin from its filename.
       
   574  *
       
   575  * @package WordPress
       
   576  * @subpackage Plugin
       
   577  * @since 1.5
       
   578  *
       
   579  * @access private
       
   580  *
       
   581  * @param string $file The filename of plugin.
       
   582  * @return string The name of a plugin.
       
   583  * @uses WP_PLUGIN_DIR
       
   584  */
       
   585 function plugin_basename($file) {
       
   586 	$file = str_replace('\\','/',$file); // sanitize for Win32 installs
       
   587 	$file = preg_replace('|/+|','/', $file); // remove any duplicate slash
       
   588 	$plugin_dir = str_replace('\\','/',WP_PLUGIN_DIR); // sanitize for Win32 installs
       
   589 	$plugin_dir = preg_replace('|/+|','/', $plugin_dir); // remove any duplicate slash
       
   590 	$mu_plugin_dir = str_replace('\\','/',WPMU_PLUGIN_DIR); // sanitize for Win32 installs
       
   591 	$mu_plugin_dir = preg_replace('|/+|','/', $mu_plugin_dir); // remove any duplicate slash
       
   592 	$file = preg_replace('#^' . preg_quote($plugin_dir, '#') . '/|^' . preg_quote($mu_plugin_dir, '#') . '/#','',$file); // get relative path from plugins dir
       
   593 	$file = trim($file, '/');
       
   594 	return $file;
       
   595 }
       
   596 
       
   597 /**
       
   598  * Gets the filesystem directory path (with trailing slash) for the plugin __FILE__ passed in
       
   599  * @package WordPress
       
   600  * @subpackage Plugin
       
   601  * @since 2.8
       
   602  *
       
   603  * @param string $file The filename of the plugin (__FILE__)
       
   604  * @return string the filesystem path of the directory that contains the plugin
       
   605  */
       
   606 function plugin_dir_path( $file ) {
       
   607 	return trailingslashit( dirname( $file ) );
       
   608 }
       
   609 
       
   610 /**
       
   611  * Gets the URL directory path (with trailing slash) for the plugin __FILE__ passed in
       
   612  * @package WordPress
       
   613  * @subpackage Plugin
       
   614  * @since 2.8
       
   615  *
       
   616  * @param string $file The filename of the plugin (__FILE__)
       
   617  * @return string the URL path of the directory that contains the plugin
       
   618  */
       
   619 function plugin_dir_url( $file ) {
       
   620 	return trailingslashit( plugins_url( '', $file ) );
       
   621 }
       
   622 
       
   623 /**
       
   624  * Set the activation hook for a plugin.
       
   625  *
       
   626  * When a plugin is activated, the action 'activate_PLUGINNAME' hook is
       
   627  * called. In the name of this hook, PLUGINNAME is replaced with the name
       
   628  * of the plugin, including the optional subdirectory. For example, when the
       
   629  * plugin is located in wp-content/plugins/sampleplugin/sample.php, then
       
   630  * the name of this hook will become 'activate_sampleplugin/sample.php'.
       
   631  *
       
   632  * When the plugin consists of only one file and is (as by default) located at
       
   633  * wp-content/plugins/sample.php the name of this hook will be
       
   634  * 'activate_sample.php'.
       
   635  *
       
   636  * @package WordPress
       
   637  * @subpackage Plugin
       
   638  * @since 2.0
       
   639  *
       
   640  * @param string $file The filename of the plugin including the path.
       
   641  * @param callback $function the function hooked to the 'activate_PLUGIN' action.
       
   642  */
       
   643 function register_activation_hook($file, $function) {
       
   644 	$file = plugin_basename($file);
       
   645 	add_action('activate_' . $file, $function);
       
   646 }
       
   647 
       
   648 /**
       
   649  * Set the deactivation hook for a plugin.
       
   650  *
       
   651  * When a plugin is deactivated, the action 'deactivate_PLUGINNAME' hook is
       
   652  * called. In the name of this hook, PLUGINNAME is replaced with the name
       
   653  * of the plugin, including the optional subdirectory. For example, when the
       
   654  * plugin is located in wp-content/plugins/sampleplugin/sample.php, then
       
   655  * the name of this hook will become 'deactivate_sampleplugin/sample.php'.
       
   656  *
       
   657  * When the plugin consists of only one file and is (as by default) located at
       
   658  * wp-content/plugins/sample.php the name of this hook will be
       
   659  * 'deactivate_sample.php'.
       
   660  *
       
   661  * @package WordPress
       
   662  * @subpackage Plugin
       
   663  * @since 2.0
       
   664  *
       
   665  * @param string $file The filename of the plugin including the path.
       
   666  * @param callback $function the function hooked to the 'deactivate_PLUGIN' action.
       
   667  */
       
   668 function register_deactivation_hook($file, $function) {
       
   669 	$file = plugin_basename($file);
       
   670 	add_action('deactivate_' . $file, $function);
       
   671 }
       
   672 
       
   673 /**
       
   674  * Set the uninstallation hook for a plugin.
       
   675  *
       
   676  * Registers the uninstall hook that will be called when the user clicks on the
       
   677  * uninstall link that calls for the plugin to uninstall itself. The link won't
       
   678  * be active unless the plugin hooks into the action.
       
   679  *
       
   680  * The plugin should not run arbitrary code outside of functions, when
       
   681  * registering the uninstall hook. In order to run using the hook, the plugin
       
   682  * will have to be included, which means that any code laying outside of a
       
   683  * function will be run during the uninstall process. The plugin should not
       
   684  * hinder the uninstall process.
       
   685  *
       
   686  * If the plugin can not be written without running code within the plugin, then
       
   687  * the plugin should create a file named 'uninstall.php' in the base plugin
       
   688  * folder. This file will be called, if it exists, during the uninstall process
       
   689  * bypassing the uninstall hook. The plugin, when using the 'uninstall.php'
       
   690  * should always check for the 'WP_UNINSTALL_PLUGIN' constant, before
       
   691  * executing.
       
   692  *
       
   693  * @since 2.7
       
   694  *
       
   695  * @param string $file
       
   696  * @param callback $callback The callback to run when the hook is called. Must be a static method or function.
       
   697  */
       
   698 function register_uninstall_hook( $file, $callback ) {
       
   699 	if ( is_array( $callback ) && is_object( $callback[0] ) ) {
       
   700 		_doing_it_wrong( __FUNCTION__, __( 'Only a static class method or function can be used in an uninstall hook.' ), '3.1' );
       
   701 		return;
       
   702 	}
       
   703 
       
   704 	// The option should not be autoloaded, because it is not needed in most
       
   705 	// cases. Emphasis should be put on using the 'uninstall.php' way of
       
   706 	// uninstalling the plugin.
       
   707 	$uninstallable_plugins = (array) get_option('uninstall_plugins');
       
   708 	$uninstallable_plugins[plugin_basename($file)] = $callback;
       
   709 	update_option('uninstall_plugins', $uninstallable_plugins);
       
   710 }
       
   711 
       
   712 /**
       
   713  * Calls the 'all' hook, which will process the functions hooked into it.
       
   714  *
       
   715  * The 'all' hook passes all of the arguments or parameters that were used for
       
   716  * the hook, which this function was called for.
       
   717  *
       
   718  * This function is used internally for apply_filters(), do_action(), and
       
   719  * do_action_ref_array() and is not meant to be used from outside those
       
   720  * functions. This function does not check for the existence of the all hook, so
       
   721  * it will fail unless the all hook exists prior to this function call.
       
   722  *
       
   723  * @package WordPress
       
   724  * @subpackage Plugin
       
   725  * @since 2.5
       
   726  * @access private
       
   727  *
       
   728  * @uses $wp_filter Used to process all of the functions in the 'all' hook
       
   729  *
       
   730  * @param array $args The collected parameters from the hook that was called.
       
   731  */
       
   732 function _wp_call_all_hook($args) {
       
   733 	global $wp_filter;
       
   734 
       
   735 	reset( $wp_filter['all'] );
       
   736 	do {
       
   737 		foreach( (array) current($wp_filter['all']) as $the_ )
       
   738 			if ( !is_null($the_['function']) )
       
   739 				call_user_func_array($the_['function'], $args);
       
   740 
       
   741 	} while ( next($wp_filter['all']) !== false );
       
   742 }
       
   743 
       
   744 /**
       
   745  * Build Unique ID for storage and retrieval.
       
   746  *
       
   747  * The old way to serialize the callback caused issues and this function is the
       
   748  * solution. It works by checking for objects and creating an a new property in
       
   749  * the class to keep track of the object and new objects of the same class that
       
   750  * need to be added.
       
   751  *
       
   752  * It also allows for the removal of actions and filters for objects after they
       
   753  * change class properties. It is possible to include the property $wp_filter_id
       
   754  * in your class and set it to "null" or a number to bypass the workaround.
       
   755  * However this will prevent you from adding new classes and any new classes
       
   756  * will overwrite the previous hook by the same class.
       
   757  *
       
   758  * Functions and static method callbacks are just returned as strings and
       
   759  * shouldn't have any speed penalty.
       
   760  *
       
   761  * @package WordPress
       
   762  * @subpackage Plugin
       
   763  * @access private
       
   764  * @since 2.2.3
       
   765  * @link http://trac.wordpress.org/ticket/3875
       
   766  *
       
   767  * @global array $wp_filter Storage for all of the filters and actions
       
   768  * @param string $tag Used in counting how many hooks were applied
       
   769  * @param callback $function Used for creating unique id
       
   770  * @param int|bool $priority Used in counting how many hooks were applied. If === false and $function is an object reference, we return the unique id only if it already has one, false otherwise.
       
   771  * @return string|bool Unique ID for usage as array key or false if $priority === false and $function is an object reference, and it does not already have a unique id.
       
   772  */
       
   773 function _wp_filter_build_unique_id($tag, $function, $priority) {
       
   774 	global $wp_filter;
       
   775 	static $filter_id_count = 0;
       
   776 
       
   777 	if ( is_string($function) )
       
   778 		return $function;
       
   779 
       
   780 	if ( is_object($function) ) {
       
   781 		// Closures are currently implemented as objects
       
   782 		$function = array( $function, '' );
       
   783 	} else {
       
   784 		$function = (array) $function;
       
   785 	}
       
   786 
       
   787 	if (is_object($function[0]) ) {
       
   788 		// Object Class Calling
       
   789 		if ( function_exists('spl_object_hash') ) {
       
   790 			return spl_object_hash($function[0]) . $function[1];
       
   791 		} else {
       
   792 			$obj_idx = get_class($function[0]).$function[1];
       
   793 			if ( !isset($function[0]->wp_filter_id) ) {
       
   794 				if ( false === $priority )
       
   795 					return false;
       
   796 				$obj_idx .= isset($wp_filter[$tag][$priority]) ? count((array)$wp_filter[$tag][$priority]) : $filter_id_count;
       
   797 				$function[0]->wp_filter_id = $filter_id_count;
       
   798 				++$filter_id_count;
       
   799 			} else {
       
   800 				$obj_idx .= $function[0]->wp_filter_id;
       
   801 			}
       
   802 
       
   803 			return $obj_idx;
       
   804 		}
       
   805 	} else if ( is_string($function[0]) ) {
       
   806 		// Static Calling
       
   807 		return $function[0] . '::' . $function[1];
       
   808 	}
       
   809 }