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+<?php
+/**
+ * Bootstrapping and helper procedural code available for use in Elgg core and plugins.
+ *
+ * @package Elgg.Core
+ * @todo These functions can't be subpackaged because they cover a wide mix of
+ * purposes and subsystems. Many of them should be moved to more relevant files.
+ */
+
+// prep core classes to be autoloadable
+spl_autoload_register('_elgg_autoload');
+elgg_register_classes(dirname(dirname(__FILE__)) . '/classes');
+
+/**
+ * Autoload classes
+ *
+ * @param string $class The name of the class
+ *
+ * @return void
+ * @throws Exception
+ * @access private
+ */
+function _elgg_autoload($class) {
+ global $CONFIG;
+
+ if (!isset($CONFIG->classes[$class]) || !include($CONFIG->classes[$class])) {
+ return false;
+ }
+}
+
+/**
+ * Register all files found in $dir as classes
+ * Need to be named MyClass.php
+ *
+ * @param string $dir The dir to look in
+ *
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_register_classes($dir) {
+ $classes = elgg_get_file_list($dir, array(), array(), array('.php'));
+
+ foreach ($classes as $class) {
+ elgg_register_class(basename($class, '.php'), $class);
+ }
+}
+
+/**
+ * Register a classname to a file.
+ *
+ * @param string $class The name of the class
+ * @param string $location The location of the file
+ *
+ * @return true
+ * @since 1.8.0
+ */
+function elgg_register_class($class, $location) {
+ global $CONFIG;
+
+ if (!isset($CONFIG->classes)) {
+ $CONFIG->classes = array();
+ }
+
+ $CONFIG->classes[$class] = $location;
+
+ return true;
+}
+
+/**
+ * Register a php library.
+ *
+ * @param string $name The name of the library
+ * @param string $location The location of the file
+ *
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_register_library($name, $location) {
+ global $CONFIG;
+
+ if (!isset($CONFIG->libraries)) {
+ $CONFIG->libraries = array();
+ }
+
+ $CONFIG->libraries[$name] = $location;
+}
+
+/**
+ * Load a php library.
+ *
+ * @param string $name The name of the library
+ *
+ * @return void
+ * @throws InvalidParameterException
+ * @since 1.8.0
+ * @todo return boolean in 1.9 to indicate whether the library has been loaded
+ */
+function elgg_load_library($name) {
+ global $CONFIG;
+
+ static $loaded_libraries = array();
+
+ if (in_array($name, $loaded_libraries)) {
+ return;
+ }
+
+ if (!isset($CONFIG->libraries)) {
+ $CONFIG->libraries = array();
+ }
+
+ if (!isset($CONFIG->libraries[$name])) {
+ $error = elgg_echo('InvalidParameterException:LibraryNotRegistered', array($name));
+ throw new InvalidParameterException($error);
+ }
+
+ if (!include_once($CONFIG->libraries[$name])) {
+ $error = elgg_echo('InvalidParameterException:LibraryNotFound', array(
+ $name,
+ $CONFIG->libraries[$name])
+ );
+ throw new InvalidParameterException($error);
+ }
+
+ $loaded_libraries[] = $name;
+}
+
+/**
+ * Forward to $location.
+ *
+ * Sends a 'Location: $location' header and exists. If headers have
+ * already been sent, returns FALSE.
+ *
+ * @param string $location URL to forward to browser to. Can be path relative to the network's URL.
+ * @param string $reason Short explanation for why we're forwarding
+ *
+ * @return false False if headers have been sent. Terminates execution if forwarding.
+ * @throws SecurityException
+ */
+function forward($location = "", $reason = 'system') {
+ if (!headers_sent($file, $line)) {
+ if ($location === REFERER) {
+ $location = $_SERVER['HTTP_REFERER'];
+ }
+
+ $location = elgg_normalize_url($location);
+
+ // return new forward location or false to stop the forward or empty string to exit
+ $current_page = current_page_url();
+ $params = array('current_url' => $current_page, 'forward_url' => $location);
+ $location = elgg_trigger_plugin_hook('forward', $reason, $params, $location);
+
+ if ($location) {
+ header("Location: {$location}");
+ exit;
+ } else if ($location === '') {
+ exit;
+ }
+ } else {
+ throw new SecurityException(elgg_echo('SecurityException:ForwardFailedToRedirect', array($file, $line)));
+ }
+}
+
+/**
+ * Register a JavaScript file for inclusion
+ *
+ * This function handles adding JavaScript to a web page. If multiple
+ * calls are made to register the same JavaScript file based on the $id
+ * variable, only the last file is included. This allows a plugin to add
+ * JavaScript from a view that may be called more than once. It also handles
+ * more than one plugin adding the same JavaScript.
+ *
+ * jQuery plugins often have filenames such as jquery.rating.js. A best practice
+ * is to base $name on the filename: "jquery.rating". It is recommended to not
+ * use version numbers in the name.
+ *
+ * The JavaScript files can be local to the server or remote (such as
+ * Google's CDN).
+ *
+ * @param string $name An identifier for the JavaScript library
+ * @param string $url URL of the JavaScript file
+ * @param string $location Page location: head or footer. (default: head)
+ * @param int $priority Priority of the JS file (lower numbers load earlier)
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_register_js($name, $url, $location = 'head', $priority = null) {
+ return elgg_register_external_file('js', $name, $url, $location, $priority);
+}
+
+/**
+ * Unregister a JavaScript file
+ *
+ * @param string $name The identifier for the JavaScript library
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_unregister_js($name) {
+ return elgg_unregister_external_file('js', $name);
+}
+
+/**
+ * Load a JavaScript resource on this page
+ *
+ * This must be called before elgg_view_page(). It can be called before the
+ * script is registered. If you do not want a script loaded, unregister it.
+ *
+ * @param string $name Identifier of the JavaScript resource
+ *
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_load_js($name) {
+ elgg_load_external_file('js', $name);
+}
+
+/**
+ * Get the JavaScript URLs that are loaded
+ *
+ * @param string $location 'head' or 'footer'
+ *
+ * @return array
+ * @since 1.8.0
+ */
+function elgg_get_loaded_js($location = 'head') {
+ return elgg_get_loaded_external_files('js', $location);
+}
+
+/**
+ * Register a CSS file for inclusion in the HTML head
+ *
+ * @param string $name An identifier for the CSS file
+ * @param string $url URL of the CSS file
+ * @param int $priority Priority of the CSS file (lower numbers load earlier)
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_register_css($name, $url, $priority = null) {
+ return elgg_register_external_file('css', $name, $url, 'head', $priority);
+}
+
+/**
+ * Unregister a CSS file
+ *
+ * @param string $name The identifier for the CSS file
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_unregister_css($name) {
+ return elgg_unregister_external_file('css', $name);
+}
+
+/**
+ * Load a CSS file for this page
+ *
+ * This must be called before elgg_view_page(). It can be called before the
+ * CSS file is registered. If you do not want a CSS file loaded, unregister it.
+ *
+ * @param string $name Identifier of the CSS file
+ *
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_load_css($name) {
+ elgg_load_external_file('css', $name);
+}
+
+/**
+ * Get the loaded CSS URLs
+ *
+ * @return array
+ * @since 1.8.0
+ */
+function elgg_get_loaded_css() {
+ return elgg_get_loaded_external_files('css', 'head');
+}
+
+/**
+ * Core registration function for external files
+ *
+ * @param string $type Type of external resource (js or css)
+ * @param string $name Identifier used as key
+ * @param string $url URL
+ * @param string $location Location in the page to include the file
+ * @param int $priority Loading priority of the file
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_register_external_file($type, $name, $url, $location, $priority = 500) {
+ global $CONFIG;
+
+ if (empty($name) || empty($url)) {
+ return false;
+ }
+
+ $url = elgg_format_url($url);
+ $url = elgg_normalize_url($url);
+
+ elgg_bootstrap_externals_data_structure($type);
+
+ $name = trim(strtolower($name));
+
+ // normalize bogus priorities, but allow empty, null, and false to be defaults.
+ if (!is_numeric($priority)) {
+ $priority = 500;
+ }
+
+ // no negative priorities right now.
+ $priority = max((int)$priority, 0);
+
+ $item = elgg_extract($name, $CONFIG->externals_map[$type]);
+
+ if ($item) {
+ // updating a registered item
+ // don't update loaded because it could already be set
+ $item->url = $url;
+ $item->location = $location;
+
+ // if loaded before registered, that means it hasn't been added to the list yet
+ if ($CONFIG->externals[$type]->contains($item)) {
+ $priority = $CONFIG->externals[$type]->move($item, $priority);
+ } else {
+ $priority = $CONFIG->externals[$type]->add($item, $priority);
+ }
+ } else {
+ $item = new stdClass();
+ $item->loaded = false;
+ $item->url = $url;
+ $item->location = $location;
+
+ $priority = $CONFIG->externals[$type]->add($item, $priority);
+ }
+
+ $CONFIG->externals_map[$type][$name] = $item;
+
+ return $priority !== false;
+}
+
+/**
+ * Unregister an external file
+ *
+ * @param string $type Type of file: js or css
+ * @param string $name The identifier of the file
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_unregister_external_file($type, $name) {
+ global $CONFIG;
+
+ elgg_bootstrap_externals_data_structure($type);
+
+ $name = trim(strtolower($name));
+ $item = elgg_extract($name, $CONFIG->externals_map[$type]);
+
+ if ($item) {
+ unset($CONFIG->externals_map[$type][$name]);
+ return $CONFIG->externals[$type]->remove($item);
+ }
+
+ return false;
+}
+
+/**
+ * Load an external resource for use on this page
+ *
+ * @param string $type Type of file: js or css
+ * @param string $name The identifier for the file
+ *
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_load_external_file($type, $name) {
+ global $CONFIG;
+
+ elgg_bootstrap_externals_data_structure($type);
+
+ $name = trim(strtolower($name));
+
+ $item = elgg_extract($name, $CONFIG->externals_map[$type]);
+
+ if ($item) {
+ // update a registered item
+ $item->loaded = true;
+ } else {
+ $item = new stdClass();
+ $item->loaded = true;
+ $item->url = '';
+ $item->location = '';
+
+ $CONFIG->externals[$type]->add($item);
+ $CONFIG->externals_map[$type][$name] = $item;
+ }
+}
+
+/**
+ * Get external resource descriptors
+ *
+ * @param string $type Type of file: js or css
+ * @param string $location Page location
+ *
+ * @return array
+ * @since 1.8.0
+ */
+function elgg_get_loaded_external_files($type, $location) {
+ global $CONFIG;
+
+ if (isset($CONFIG->externals) && $CONFIG->externals[$type] instanceof ElggPriorityList) {
+ $items = $CONFIG->externals[$type]->getElements();
+
+ $callback = "return \$v->loaded == true && \$v->location == '$location';";
+ $items = array_filter($items, create_function('$v', $callback));
+ if ($items) {
+ array_walk($items, create_function('&$v,$k', '$v = $v->url;'));
+ }
+ return $items;
+ }
+ return array();
+}
+
+/**
+ * Bootstraps the externals data structure in $CONFIG.
+ *
+ * @param string $type The type of external, js or css.
+ * @access private
+ */
+function elgg_bootstrap_externals_data_structure($type) {
+ global $CONFIG;
+
+ if (!isset($CONFIG->externals)) {
+ $CONFIG->externals = array();
+ }
+
+ if (!isset($CONFIG->externals[$type]) || !$CONFIG->externals[$type] instanceof ElggPriorityList) {
+ $CONFIG->externals[$type] = new ElggPriorityList();
+ }
+
+ if (!isset($CONFIG->externals_map)) {
+ $CONFIG->externals_map = array();
+ }
+
+ if (!isset($CONFIG->externals_map[$type])) {
+ $CONFIG->externals_map[$type] = array();
+ }
+}
+
+/**
+ * Returns a list of files in $directory.
+ *
+ * Only returns files. Does not recurse into subdirs.
+ *
+ * @param string $directory Directory to look in
+ * @param array $exceptions Array of filenames to ignore
+ * @param array $list Array of files to append to
+ * @param mixed $extensions Array of extensions to allow, NULL for all. Use a dot: array('.php').
+ *
+ * @return array Filenames in $directory, in the form $directory/filename.
+ */
+function elgg_get_file_list($directory, $exceptions = array(), $list = array(),
+$extensions = NULL) {
+
+ $directory = sanitise_filepath($directory);
+ if ($handle = opendir($directory)) {
+ while (($file = readdir($handle)) !== FALSE) {
+ if (!is_file($directory . $file) || in_array($file, $exceptions)) {
+ continue;
+ }
+
+ if (is_array($extensions)) {
+ if (in_array(strrchr($file, '.'), $extensions)) {
+ $list[] = $directory . $file;
+ }
+ } else {
+ $list[] = $directory . $file;
+ }
+ }
+ closedir($handle);
+ }
+
+ return $list;
+}
+
+/**
+ * Sanitise file paths ensuring that they begin and end with slashes etc.
+ *
+ * @param string $path The path
+ * @param bool $append_slash Add tailing slash
+ *
+ * @return string
+ */
+function sanitise_filepath($path, $append_slash = TRUE) {
+ // Convert to correct UNIX paths
+ $path = str_replace('\\', '/', $path);
+ $path = str_replace('../', '/', $path);
+ // replace // with / except when preceeded by :
+ $path = preg_replace("/([^:])\/\//", "$1/", $path);
+
+ // Sort trailing slash
+ $path = trim($path);
+ // rtrim defaults plus /
+ $path = rtrim($path, " \n\t\0\x0B/");
+
+ if ($append_slash) {
+ $path = $path . '/';
+ }
+
+ return $path;
+}
+
+/**
+ * Queues a message to be displayed.
+ *
+ * Messages will not be displayed immediately, but are stored in
+ * for later display, usually upon next page load.
+ *
+ * The method of displaying these messages differs depending upon plugins and
+ * viewtypes. The core default viewtype retrieves messages in
+ * {@link views/default/page/shells/default.php} and displays messages as
+ * javascript popups.
+ *
+ * @internal Messages are stored as strings in the $_SESSION['msg'][$register] array.
+ *
+ * @warning This function is used to both add to and clear the message
+ * stack. If $messages is null, $register will be returned and cleared.
+ * If $messages is null and $register is empty, all messages will be
+ * returned and removed.
+ *
+ * @important This function handles the standard {@link system_message()} ($register =
+ * 'messages') as well as {@link register_error()} messages ($register = 'errors').
+ *
+ * @param mixed $message Optionally, a single message or array of messages to add, (default: null)
+ * @param string $register Types of message: "error", "success" (default: success)
+ * @param bool $count Count the number of messages (default: false)
+ *
+ * @return bool|array Either the array of messages, or a response regarding
+ * whether the message addition was successful.
+ * @todo Clean up. Separate registering messages and retrieving them.
+ */
+function system_messages($message = null, $register = "success", $count = false) {
+ if (!isset($_SESSION['msg'])) {
+ $_SESSION['msg'] = array();
+ }
+ if (!isset($_SESSION['msg'][$register]) && !empty($register)) {
+ $_SESSION['msg'][$register] = array();
+ }
+ if (!$count) {
+ if (!empty($message) && is_array($message)) {
+ $_SESSION['msg'][$register] = array_merge($_SESSION['msg'][$register], $message);
+ return true;
+ } else if (!empty($message) && is_string($message)) {
+ $_SESSION['msg'][$register][] = $message;
+ return true;
+ } else if (is_null($message)) {
+ if ($register != "") {
+ $returnarray = array();
+ $returnarray[$register] = $_SESSION['msg'][$register];
+ $_SESSION['msg'][$register] = array();
+ } else {
+ $returnarray = $_SESSION['msg'];
+ $_SESSION['msg'] = array();
+ }
+ return $returnarray;
+ }
+ } else {
+ if (!empty($register)) {
+ return sizeof($_SESSION['msg'][$register]);
+ } else {
+ $count = 0;
+ foreach ($_SESSION['msg'] as $submessages) {
+ $count += sizeof($submessages);
+ }
+ return $count;
+ }
+ }
+ return false;
+}
+
+/**
+ * Counts the number of messages, either globally or in a particular register
+ *
+ * @param string $register Optionally, the register
+ *
+ * @return integer The number of messages
+ */
+function count_messages($register = "") {
+ return system_messages(null, $register, true);
+}
+
+/**
+ * Display a system message on next page load.
+ *
+ * @see system_messages()
+ *
+ * @param string|array $message Message or messages to add
+ *
+ * @return bool
+ */
+function system_message($message) {
+ return system_messages($message, "success");
+}
+
+/**
+ * Display an error on next page load.
+ *
+ * @see system_messages()
+ *
+ * @param string|array $error Error or errors to add
+ *
+ * @return bool
+ */
+function register_error($error) {
+ return system_messages($error, "error");
+}
+
+/**
+ * Register a callback as an Elgg event handler.
+ *
+ * Events are emitted by Elgg when certain actions occur. Plugins
+ * can respond to these events or halt them completely by registering a handler
+ * as a callback to an event. Multiple handlers can be registered for
+ * the same event and will be executed in order of $priority. Any handler
+ * returning false will halt the execution chain.
+ *
+ * This function is called with the event name, event type, and handler callback name.
+ * Setting the optional $priority allows plugin authors to specify when the
+ * callback should be run. Priorities for plugins should be 1-1000.
+ *
+ * The callback is passed 3 arguments when called: $event, $type, and optional $params.
+ *
+ * $event is the name of event being emitted.
+ * $type is the type of event or object concerned.
+ * $params is an optional parameter passed that can include a related object. See
+ * specific event documentation for details on which events pass what parameteres.
+ *
+ * @tip If a priority isn't specified it is determined by the order the handler was
+ * registered relative to the event and type. For plugins, this generally means
+ * the earlier the plugin is in the load order, the earlier the priorities are for
+ * any event handlers.
+ *
+ * @tip $event and $object_type can use the special keyword 'all'. Handler callbacks registered
+ * with $event = all will be called for all events of type $object_type. Similarly,
+ * callbacks registered with $object_type = all will be called for all events of type
+ * $event, regardless of $object_type. If $event and $object_type both are 'all', the
+ * handler callback will be called for all events.
+ *
+ * @tip Event handler callbacks are considered in the follow order:
+ * - Specific registration where 'all' isn't used.
+ * - Registration where 'all' is used for $event only.
+ * - Registration where 'all' is used for $type only.
+ * - Registration where 'all' is used for both.
+ *
+ * @warning If you use the 'all' keyword, you must have logic in the handler callback to
+ * test the passed parameters before taking an action.
+ *
+ * @tip When referring to events, the preferred syntax is "event, type".
+ *
+ * @internal Events are stored in $CONFIG->events as:
+ * <code>
+ * $CONFIG->events[$event][$type][$priority] = $callback;
+ * </code>
+ *
+ * @param string $event The event type
+ * @param string $object_type The object type
+ * @param string $callback The handler callback
+ * @param int $priority The priority - 0 is default, negative before, positive after
+ *
+ * @return bool
+ * @link http://docs.elgg.org/Tutorials/Plugins/Events
+ * @example events/basic.php Basic example of registering an event handler callback.
+ * @example events/advanced.php Advanced example of registering an event handler
+ * callback and halting execution.
+ * @example events/all.php Example of how to use the 'all' keyword.
+ */
+function elgg_register_event_handler($event, $object_type, $callback, $priority = 500) {
+ global $CONFIG;
+
+ if (empty($event) || empty($object_type)) {
+ return false;
+ }
+
+ if (!isset($CONFIG->events)) {
+ $CONFIG->events = array();
+ }
+ if (!isset($CONFIG->events[$event])) {
+ $CONFIG->events[$event] = array();
+ }
+ if (!isset($CONFIG->events[$event][$object_type])) {
+ $CONFIG->events[$event][$object_type] = array();
+ }
+
+ if (!is_callable($callback, true)) {
+ return false;
+ }
+
+ $priority = max((int) $priority, 0);
+
+ while (isset($CONFIG->events[$event][$object_type][$priority])) {
+ $priority++;
+ }
+ $CONFIG->events[$event][$object_type][$priority] = $callback;
+ ksort($CONFIG->events[$event][$object_type]);
+ return true;
+}
+
+/**
+ * Unregisters a callback for an event.
+ *
+ * @param string $event The event type
+ * @param string $object_type The object type
+ * @param string $callback The callback
+ *
+ * @return void
+ * @since 1.7
+ */
+function elgg_unregister_event_handler($event, $object_type, $callback) {
+ global $CONFIG;
+
+ if (isset($CONFIG->events[$event]) && isset($CONFIG->events[$event][$object_type])) {
+ foreach ($CONFIG->events[$event][$object_type] as $key => $event_callback) {
+ if ($event_callback == $callback) {
+ unset($CONFIG->events[$event][$object_type][$key]);
+ }
+ }
+ }
+}
+
+/**
+ * Trigger an Elgg Event and run all handler callbacks registered to that event, type.
+ *
+ * This function runs all handlers registered to $event, $object_type or
+ * the special keyword 'all' for either or both.
+ *
+ * $event is usually a verb: create, update, delete, annotation.
+ *
+ * $object_type is usually a noun: object, group, user, annotation, relationship, metadata.
+ *
+ * $object is usually an Elgg* object assciated with the event.
+ *
+ * @warning Elgg events should only be triggered by core. Plugin authors should use
+ * {@link trigger_elgg_plugin_hook()} instead.
+ *
+ * @tip When referring to events, the preferred syntax is "event, type".
+ *
+ * @internal Only rarely should events be changed, added, or removed in core.
+ * When making changes to events, be sure to first create a ticket on Github.
+ *
+ * @internal @tip Think of $object_type as the primary namespace element, and
+ * $event as the secondary namespace.
+ *
+ * @param string $event The event type
+ * @param string $object_type The object type
+ * @param string $object The object involved in the event
+ *
+ * @return bool The result of running all handler callbacks.
+ * @link http://docs.elgg.org/Tutorials/Core/Events
+ * @internal @example events/emit.php Basic emitting of an Elgg event.
+ */
+function elgg_trigger_event($event, $object_type, $object = null) {
+ global $CONFIG;
+
+ $events = array();
+ if (isset($CONFIG->events[$event][$object_type])) {
+ $events[] = $CONFIG->events[$event][$object_type];
+ }
+ if (isset($CONFIG->events['all'][$object_type])) {
+ $events[] = $CONFIG->events['all'][$object_type];
+ }
+ if (isset($CONFIG->events[$event]['all'])) {
+ $events[] = $CONFIG->events[$event]['all'];
+ }
+ if (isset($CONFIG->events['all']['all'])) {
+ $events[] = $CONFIG->events['all']['all'];
+ }
+
+ $args = array($event, $object_type, $object);
+
+ foreach ($events as $callback_list) {
+ if (is_array($callback_list)) {
+ foreach ($callback_list as $callback) {
+ if (is_callable($callback) && (call_user_func_array($callback, $args) === false)) {
+ return false;
+ }
+ }
+ }
+ }
+
+ return true;
+}
+
+/**
+ * Register a callback as a plugin hook handler.
+ *
+ * Plugin hooks allow developers to losely couple plugins and features by
+ * repsonding to and emitting {@link elgg_trigger_plugin_hook()} customizable hooks.
+ * Handler callbacks can respond to the hook, change the details of the hook, or
+ * ignore it.
+ *
+ * Multiple handlers can be registered for a plugin hook, and each callback
+ * is called in order of priority. If the return value of a handler is not
+ * null, that value is passed to the next callback in the call stack. When all
+ * callbacks have been run, the final value is passed back to the caller
+ * via {@link elgg_trigger_plugin_hook()}.
+ *
+ * Similar to Elgg Events, plugin hook handler callbacks are registered by passing
+ * a hook, a type, and a priority.
+ *
+ * The callback is passed 4 arguments when called: $hook, $type, $value, and $params.
+ *
+ * - str $hook The name of the hook.
+ * - str $type The type of hook.
+ * - mixed $value The return value of the last handler or the default
+ * value if no other handlers have been called.
+ * - mixed $params An optional array of parameters. Used to provide additional
+ * information to plugins.
+ *
+ * @internal Plugin hooks are stored in $CONFIG->hooks as:
+ * <code>
+ * $CONFIG->hooks[$hook][$type][$priority] = $callback;
+ * </code>
+ *
+ * @tip Plugin hooks are similar to Elgg Events in that Elgg emits
+ * a plugin hook when certain actions occur, but a plugin hook allows you to alter the
+ * parameters, as well as halt execution.
+ *
+ * @tip If a priority isn't specified it is determined by the order the handler was
+ * registered relative to the event and type. For plugins, this generally means
+ * the earlier the plugin is in the load order, the earlier the priorities are for
+ * any event handlers.
+ *
+ * @tip Like Elgg Events, $hook and $type can use the special keyword 'all'.
+ * Handler callbacks registered with $hook = all will be called for all hooks
+ * of type $type. Similarly, handlers registered with $type = all will be
+ * called for all hooks of type $event, regardless of $object_type. If $hook
+ * and $type both are 'all', the handler will be called for all hooks.
+ *
+ * @tip Plugin hooks are sometimes used to gather lists from plugins. This is
+ * usually done by pushing elements into an array passed in $params. Be sure
+ * to append to and then return $value so you don't overwrite other plugin's
+ * values.
+ *
+ * @warning Unlike Elgg Events, a handler that returns false will NOT halt the
+ * execution chain.
+ *
+ * @param string $hook The name of the hook
+ * @param string $type The type of the hook
+ * @param callable $callback The name of a valid function or an array with object and method
+ * @param int $priority The priority - 500 is default, lower numbers called first
+ *
+ * @return bool
+ *
+ * @example hooks/register/basic.php Registering for a plugin hook and examining the variables.
+ * @example hooks/register/advanced.php Registering for a plugin hook and changing the params.
+ * @link http://docs.elgg.org/Tutorials/Plugins/Hooks
+ * @since 1.8.0
+ */
+function elgg_register_plugin_hook_handler($hook, $type, $callback, $priority = 500) {
+ global $CONFIG;
+
+ if (empty($hook) || empty($type)) {
+ return false;
+ }
+
+ if (!isset($CONFIG->hooks)) {
+ $CONFIG->hooks = array();
+ }
+ if (!isset($CONFIG->hooks[$hook])) {
+ $CONFIG->hooks[$hook] = array();
+ }
+ if (!isset($CONFIG->hooks[$hook][$type])) {
+ $CONFIG->hooks[$hook][$type] = array();
+ }
+
+ if (!is_callable($callback, true)) {
+ return false;
+ }
+
+ $priority = max((int) $priority, 0);
+
+ while (isset($CONFIG->hooks[$hook][$type][$priority])) {
+ $priority++;
+ }
+ $CONFIG->hooks[$hook][$type][$priority] = $callback;
+ ksort($CONFIG->hooks[$hook][$type]);
+ return true;
+}
+
+/**
+ * Unregister a callback as a plugin hook.
+ *
+ * @param string $hook The name of the hook
+ * @param string $entity_type The name of the type of entity (eg "user", "object" etc)
+ * @param callable $callback The PHP callback to be removed
+ *
+ * @return void
+ * @since 1.8.0
+ */
+function elgg_unregister_plugin_hook_handler($hook, $entity_type, $callback) {
+ global $CONFIG;
+
+ if (isset($CONFIG->hooks[$hook]) && isset($CONFIG->hooks[$hook][$entity_type])) {
+ foreach ($CONFIG->hooks[$hook][$entity_type] as $key => $hook_callback) {
+ if ($hook_callback == $callback) {
+ unset($CONFIG->hooks[$hook][$entity_type][$key]);
+ }
+ }
+ }
+}
+
+/**
+ * Trigger a Plugin Hook and run all handler callbacks registered to that hook:type.
+ *
+ * This function runs all handlers regsitered to $hook, $type or
+ * the special keyword 'all' for either or both.
+ *
+ * Use $params to send additional information to the handler callbacks.
+ *
+ * $returnvalue Is the initial value to pass to the handlers, which can
+ * then change it. It is useful to use $returnvalue to set defaults.
+ * If no handlers are registered, $returnvalue is immediately returned.
+ *
+ * $hook is usually a verb: import, get_views, output.
+ *
+ * $type is usually a noun: user, ecml, page.
+ *
+ * @tip Like Elgg Events, $hook and $type can use the special keyword 'all'.
+ * Handler callbacks registered with $hook = all will be called for all hooks
+ * of type $type. Similarly, handlers registered with $type = all will be
+ * called for all hooks of type $event, regardless of $object_type. If $hook
+ * and $type both are 'all', the handler will be called for all hooks.
+ *
+ * @internal The checks for $hook and/or $type not being equal to 'all' is to
+ * prevent a plugin hook being registered with an 'all' being called more than
+ * once if the trigger occurs with an 'all'. An example in core of this is in
+ * actions.php:
+ * elgg_trigger_plugin_hook('action_gatekeeper:permissions:check', 'all', ...)
+ *
+ * @see elgg_register_plugin_hook_handler()
+ *
+ * @param string $hook The name of the hook to trigger ("all" will
+ * trigger for all $types regardless of $hook value)
+ * @param string $type The type of the hook to trigger ("all" will
+ * trigger for all $hooks regardless of $type value)
+ * @param mixed $params Additional parameters to pass to the handlers
+ * @param mixed $returnvalue An initial return value
+ *
+ * @return mixed|null The return value of the last handler callback called
+ *
+ * @example hooks/trigger/basic.php Trigger a hook that determins if execution
+ * should continue.
+ * @example hooks/trigger/advanced.php Trigger a hook with a default value and use
+ * the results to populate a menu.
+ * @example hooks/basic.php Trigger and respond to a basic plugin hook.
+ * @link http://docs.elgg.org/Tutorials/Plugins/Hooks
+ *
+ * @since 1.8.0
+ */
+function elgg_trigger_plugin_hook($hook, $type, $params = null, $returnvalue = null) {
+ global $CONFIG;
+
+ $hooks = array();
+ if (isset($CONFIG->hooks[$hook][$type])) {
+ if ($hook != 'all' && $type != 'all') {
+ $hooks[] = $CONFIG->hooks[$hook][$type];
+ }
+ }
+ if (isset($CONFIG->hooks['all'][$type])) {
+ if ($type != 'all') {
+ $hooks[] = $CONFIG->hooks['all'][$type];
+ }
+ }
+ if (isset($CONFIG->hooks[$hook]['all'])) {
+ if ($hook != 'all') {
+ $hooks[] = $CONFIG->hooks[$hook]['all'];
+ }
+ }
+ if (isset($CONFIG->hooks['all']['all'])) {
+ $hooks[] = $CONFIG->hooks['all']['all'];
+ }
+
+ foreach ($hooks as $callback_list) {
+ if (is_array($callback_list)) {
+ foreach ($callback_list as $hookcallback) {
+ if (is_callable($hookcallback)) {
+ $args = array($hook, $type, $returnvalue, $params);
+ $temp_return_value = call_user_func_array($hookcallback, $args);
+ if (!is_null($temp_return_value)) {
+ $returnvalue = $temp_return_value;
+ }
+ }
+ }
+ }
+ }
+
+ return $returnvalue;
+}
+
+/**
+ * Intercepts, logs, and displays uncaught exceptions.
+ *
+ * @warning This function should never be called directly.
+ *
+ * @see http://www.php.net/set-exception-handler
+ *
+ * @param Exception $exception The exception being handled
+ *
+ * @return void
+ * @access private
+ */
+function _elgg_php_exception_handler($exception) {
+ $timestamp = time();
+ error_log("Exception #$timestamp: $exception");
+
+ // Wipe any existing output buffer
+ ob_end_clean();
+
+ // make sure the error isn't cached
+ header("Cache-Control: no-cache, must-revalidate", true);
+ header('Expires: Fri, 05 Feb 1982 00:00:00 -0500', true);
+ // @note Do not send a 500 header because it is not a server error
+
+ try {
+ // we don't want the 'pagesetup', 'system' event to fire
+ global $CONFIG;
+ $CONFIG->pagesetupdone = true;
+
+ elgg_set_viewtype('failsafe');
+ if (elgg_is_admin_logged_in()) {
+ $body = elgg_view("messages/exceptions/admin_exception", array(
+ 'object' => $exception,
+ 'ts' => $timestamp
+ ));
+ } else {
+ $body = elgg_view("messages/exceptions/exception", array(
+ 'object' => $exception,
+ 'ts' => $timestamp
+ ));
+ }
+ echo elgg_view_page(elgg_echo('exception:title'), $body);
+ } catch (Exception $e) {
+ $timestamp = time();
+ $message = $e->getMessage();
+ echo "Fatal error in exception handler. Check log for Exception #$timestamp";
+ error_log("Exception #$timestamp : fatal error in exception handler : $message");
+ }
+}
+
+/**
+ * Intercepts catchable PHP errors.
+ *
+ * @warning This function should never be called directly.
+ *
+ * @internal
+ * For catchable fatal errors, throws an Exception with the error.
+ *
+ * For non-fatal errors, depending upon the debug settings, either
+ * log the error or ignore it.
+ *
+ * @see http://www.php.net/set-error-handler
+ *
+ * @param int $errno The level of the error raised
+ * @param string $errmsg The error message
+ * @param string $filename The filename the error was raised in
+ * @param int $linenum The line number the error was raised at
+ * @param array $vars An array that points to the active symbol table where error occurred
+ *
+ * @return true
+ * @throws Exception
+ * @access private
+ * @todo Replace error_log calls with elgg_log calls.
+ */
+function _elgg_php_error_handler($errno, $errmsg, $filename, $linenum, $vars) {
+ $error = date("Y-m-d H:i:s (T)") . ": \"$errmsg\" in file $filename (line $linenum)";
+
+ switch ($errno) {
+ case E_USER_ERROR:
+ error_log("PHP ERROR: $error");
+ register_error("ERROR: $error");
+
+ // Since this is a fatal error, we want to stop any further execution but do so gracefully.
+ throw new Exception($error);
+ break;
+
+ case E_WARNING :
+ case E_USER_WARNING :
+ case E_RECOVERABLE_ERROR: // (e.g. type hint violation)
+
+ // check if the error wasn't suppressed by the error control operator (@)
+ if (error_reporting()) {
+ error_log("PHP WARNING: $error");
+ }
+ break;
+
+ default:
+ global $CONFIG;
+ if (isset($CONFIG->debug) && $CONFIG->debug === 'NOTICE') {
+ error_log("PHP NOTICE: $error");
+ }
+ }
+
+ return true;
+}
+
+/**
+ * Display or log a message.
+ *
+ * If $level is >= to the debug setting in {@link $CONFIG->debug}, the
+ * message will be sent to {@link elgg_dump()}. Messages with lower
+ * priority than {@link $CONFIG->debug} are ignored.
+ *
+ * {@link elgg_dump()} outputs all levels but NOTICE to screen by default.
+ *
+ * @note No messages will be displayed unless debugging has been enabled.
+ *
+ * @param string $message User message
+ * @param string $level NOTICE | WARNING | ERROR | DEBUG
+ *
+ * @return bool
+ * @since 1.7.0
+ * @todo This is complicated and confusing. Using int constants for debug levels will
+ * make things easier.
+ */
+function elgg_log($message, $level = 'NOTICE') {
+ global $CONFIG;
+
+ // only log when debugging is enabled
+ if (isset($CONFIG->debug)) {
+ // debug to screen or log?
+ $to_screen = !($CONFIG->debug == 'NOTICE');
+
+ switch ($level) {
+ case 'ERROR':
+ // always report
+ elgg_dump("$level: $message", $to_screen, $level);
+ break;
+ case 'WARNING':
+ case 'DEBUG':
+ // report except if user wants only errors
+ if ($CONFIG->debug != 'ERROR') {
+ elgg_dump("$level: $message", $to_screen, $level);
+ }
+ break;
+ case 'NOTICE':
+ default:
+ // only report when lowest level is desired
+ if ($CONFIG->debug == 'NOTICE') {
+ elgg_dump("$level: $message", FALSE, $level);
+ }
+ break;
+ }
+
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
+/**
+ * Logs or displays $value.
+ *
+ * If $to_screen is true, $value is displayed to screen. Else,
+ * it is handled by PHP's {@link error_log()} function.
+ *
+ * A {@elgg_plugin_hook debug log} is called. If a handler returns
+ * false, it will stop the default logging method.
+ *
+ * @param mixed $value The value
+ * @param bool $to_screen Display to screen?
+ * @param string $level The debug level
+ *
+ * @return void
+ * @since 1.7.0
+ */
+function elgg_dump($value, $to_screen = TRUE, $level = 'NOTICE') {
+ global $CONFIG;
+
+ // plugin can return false to stop the default logging method
+ $params = array(
+ 'level' => $level,
+ 'msg' => $value,
+ 'to_screen' => $to_screen,
+ );
+ if (!elgg_trigger_plugin_hook('debug', 'log', $params, true)) {
+ return;
+ }
+
+ // Do not want to write to screen before page creation has started.
+ // This is not fool-proof but probably fixes 95% of the cases when logging
+ // results in data sent to the browser before the page is begun.
+ if (!isset($CONFIG->pagesetupdone)) {
+ $to_screen = FALSE;
+ }
+
+ // Do not want to write to JS or CSS pages
+ if (elgg_in_context('js') || elgg_in_context('css')) {
+ $to_screen = FALSE;
+ }
+
+ if ($to_screen == TRUE) {
+ echo '<pre>';
+ print_r($value);
+ echo '</pre>';
+ } else {
+ error_log(print_r($value, TRUE));
+ }
+}
+
+/**
+ * Sends a notice about deprecated use of a function, view, etc.
+ *
+ * This function either displays or logs the deprecation message,
+ * depending upon the deprecation policies in {@link CODING.txt}.
+ * Logged messages are sent with the level of 'WARNING'. Only admins
+ * get visual deprecation notices. When non-admins are logged in, the
+ * notices are sent to PHP's log through elgg_dump().
+ *
+ * A user-visual message will be displayed if $dep_version is greater
+ * than 1 minor releases lower than the current Elgg version, or at all
+ * lower than the current Elgg major version.
+ *
+ * @note This will always at least log a warning. Don't use to pre-deprecate things.
+ * This assumes we are releasing in order and deprecating according to policy.
+ *
+ * @see CODING.txt
+ *
+ * @param string $msg Message to log / display.
+ * @param string $dep_version Human-readable *release* version: 1.7, 1.8, ...
+ * @param int $backtrace_level How many levels back to display the backtrace.
+ * Useful if calling from functions that are called
+ * from other places (like elgg_view()). Set to -1
+ * for a full backtrace.
+ *
+ * @return bool
+ * @since 1.7.0
+ */
+function elgg_deprecated_notice($msg, $dep_version, $backtrace_level = 1) {
+ // if it's a major release behind, visual and logged
+ // if it's a 1 minor release behind, visual and logged
+ // if it's for current minor release, logged.
+ // bugfixes don't matter because we are not deprecating between them
+
+ if (!$dep_version) {
+ return false;
+ }
+
+ $elgg_version = get_version(true);
+ $elgg_version_arr = explode('.', $elgg_version);
+ $elgg_major_version = (int)$elgg_version_arr[0];
+ $elgg_minor_version = (int)$elgg_version_arr[1];
+
+ $dep_major_version = (int)$dep_version;
+ $dep_minor_version = 10 * ($dep_version - $dep_major_version);
+
+ $visual = false;
+
+ if (($dep_major_version < $elgg_major_version) ||
+ ($dep_minor_version < $elgg_minor_version)) {
+ $visual = true;
+ }
+
+ $msg = "Deprecated in $dep_major_version.$dep_minor_version: $msg";
+
+ if ($visual && elgg_is_admin_logged_in()) {
+ register_error($msg);
+ }
+
+ // Get a file and line number for the log. Never show this in the UI.
+ // Skip over the function that sent this notice and see who called the deprecated
+ // function itself.
+ $msg .= " Called from ";
+ $stack = array();
+ $backtrace = debug_backtrace();
+ // never show this call.
+ array_shift($backtrace);
+ $i = count($backtrace);
+
+ foreach ($backtrace as $trace) {
+ $stack[] = "[#$i] {$trace['file']}:{$trace['line']}";
+ $i--;
+
+ if ($backtrace_level > 0) {
+ if ($backtrace_level <= 1) {
+ break;
+ }
+ $backtrace_level--;
+ }
+ }
+
+ $msg .= implode("<br /> -> ", $stack);
+
+ elgg_log($msg, 'WARNING');
+
+ return true;
+}
+
+/**
+ * Returns the current page's complete URL.
+ *
+ * The current URL is assembled using the network's wwwroot and the request URI
+ * in $_SERVER as populated by the web server. This function will include
+ * any schemes, usernames and passwords, and ports.
+ *
+ * @return string The current page URL.
+ */
+function current_page_url() {
+ $url = parse_url(elgg_get_site_url());
+
+ $page = $url['scheme'] . "://";
+
+ // user/pass
+ if ((isset($url['user'])) && ($url['user'])) {
+ $page .= $url['user'];
+ }
+ if ((isset($url['pass'])) && ($url['pass'])) {
+ $page .= ":" . $url['pass'];
+ }
+ if ((isset($url['user']) && $url['user']) ||
+ (isset($url['pass']) && $url['pass'])) {
+ $page .= "@";
+ }
+
+ $page .= $url['host'];
+
+ if ((isset($url['port'])) && ($url['port'])) {
+ $page .= ":" . $url['port'];
+ }
+
+ $page = trim($page, "/");
+
+ $page .= $_SERVER['REQUEST_URI'];
+
+ return $page;
+}
+
+/**
+ * Return the full URL of the current page.
+ *
+ * @return string The URL
+ * @todo Combine / replace with current_page_url()
+ */
+function full_url() {
+ $s = empty($_SERVER["HTTPS"]) ? '' : ($_SERVER["HTTPS"] == "on") ? "s" : "";
+ $protocol = substr(strtolower($_SERVER["SERVER_PROTOCOL"]), 0,
+ strpos(strtolower($_SERVER["SERVER_PROTOCOL"]), "/")) . $s;
+
+ $port = ($_SERVER["SERVER_PORT"] == "80" || $_SERVER["SERVER_PORT"] == "443") ?
+ "" : (":" . $_SERVER["SERVER_PORT"]);
+
+ // This is here to prevent XSS in poorly written browsers used by 80% of the population.
+ // https://github.com/Elgg/Elgg/commit/0c947e80f512cb0a482b1864fd0a6965c8a0cd4a
+ $quotes = array('\'', '"');
+ $encoded = array('%27', '%22');
+
+ return $protocol . "://" . $_SERVER['SERVER_NAME'] . $port .
+ str_replace($quotes, $encoded, $_SERVER['REQUEST_URI']);
+}
+
+/**
+ * Builds a URL from the a parts array like one returned by {@link parse_url()}.
+ *
+ * @note If only partial information is passed, a partial URL will be returned.
+ *
+ * @param array $parts Associative array of URL components like parse_url() returns
+ * @param bool $html_encode HTML Encode the url?
+ *
+ * @return string Full URL
+ * @since 1.7.0
+ */
+function elgg_http_build_url(array $parts, $html_encode = TRUE) {
+ // build only what's given to us.
+ $scheme = isset($parts['scheme']) ? "{$parts['scheme']}://" : '';
+ $host = isset($parts['host']) ? "{$parts['host']}" : '';
+ $port = isset($parts['port']) ? ":{$parts['port']}" : '';
+ $path = isset($parts['path']) ? "{$parts['path']}" : '';
+ $query = isset($parts['query']) ? "?{$parts['query']}" : '';
+
+ $string = $scheme . $host . $port . $path . $query;
+
+ if ($html_encode) {
+ return elgg_format_url($string);
+ } else {
+ return $string;
+ }
+}
+
+/**
+ * Adds action tokens to URL
+ *
+ * As of 1.7.0 action tokens are required on all actions.
+ * Use this function to append action tokens to a URL's GET parameters.
+ * This will preserve any existing GET parameters.
+ *
+ * @note If you are using {@elgg_view input/form} you don't need to
+ * add tokens to the action. The form view automatically handles
+ * tokens.
+ *
+ * @param string $url Full action URL
+ * @param bool $html_encode HTML encode the url? (default: false)
+ *
+ * @return string URL with action tokens
+ * @since 1.7.0
+ * @link http://docs.elgg.org/Tutorials/Actions
+ */
+function elgg_add_action_tokens_to_url($url, $html_encode = FALSE) {
+ $components = parse_url(elgg_normalize_url($url));
+
+ if (isset($components['query'])) {
+ $query = elgg_parse_str($components['query']);
+ } else {
+ $query = array();
+ }
+
+ if (isset($query['__elgg_ts']) && isset($query['__elgg_token'])) {
+ return $url;
+ }
+
+ // append action tokens to the existing query
+ $query['__elgg_ts'] = time();
+ $query['__elgg_token'] = generate_action_token($query['__elgg_ts']);
+ $components['query'] = http_build_query($query);
+
+ // rebuild the full url
+ return elgg_http_build_url($components, $html_encode);
+}
+
+/**
+ * Removes an element from a URL's query string.
+ *
+ * @note You can send a partial URL string.
+ *
+ * @param string $url Full URL
+ * @param string $element The element to remove
+ *
+ * @return string The new URL with the query element removed.
+ * @since 1.7.0
+ */
+function elgg_http_remove_url_query_element($url, $element) {
+ $url_array = parse_url($url);
+
+ if (isset($url_array['query'])) {
+ $query = elgg_parse_str($url_array['query']);
+ } else {
+ // nothing to remove. Return original URL.
+ return $url;
+ }
+
+ if (array_key_exists($element, $query)) {
+ unset($query[$element]);
+ }
+
+ $url_array['query'] = http_build_query($query);
+ $string = elgg_http_build_url($url_array, false);
+ return $string;
+}
+
+/**
+ * Adds an element or elements to a URL's query string.
+ *
+ * @param string $url The URL
+ * @param array $elements Key/value pairs to add to the URL
+ *
+ * @return string The new URL with the query strings added
+ * @since 1.7.0
+ */
+function elgg_http_add_url_query_elements($url, array $elements) {
+ $url_array = parse_url($url);
+
+ if (isset($url_array['query'])) {
+ $query = elgg_parse_str($url_array['query']);
+ } else {
+ $query = array();
+ }
+
+ foreach ($elements as $k => $v) {
+ $query[$k] = $v;
+ }
+
+ $url_array['query'] = http_build_query($query);
+ $string = elgg_http_build_url($url_array, false);
+
+ return $string;
+}
+
+/**
+ * Test if two URLs are functionally identical.
+ *
+ * @tip If $ignore_params is used, neither the name nor its value will be considered when comparing.
+ *
+ * @tip The order of GET params doesn't matter.
+ *
+ * @param string $url1 First URL
+ * @param string $url2 Second URL
+ * @param array $ignore_params GET params to ignore in the comparison
+ *
+ * @return bool
+ * @since 1.8.0
+ */
+function elgg_http_url_is_identical($url1, $url2, $ignore_params = array('offset', 'limit')) {
+ // if the server portion is missing but it starts with / then add the url in.
+ // @todo use elgg_normalize_url()
+ if (elgg_substr($url1, 0, 1) == '/') {
+ $url1 = elgg_get_site_url() . ltrim($url1, '/');
+ }
+
+ if (elgg_substr($url1, 0, 1) == '/') {
+ $url2 = elgg_get_site_url() . ltrim($url2, '/');
+ }
+
+ // @todo - should probably do something with relative URLs
+
+ if ($url1 == $url2) {
+ return TRUE;
+ }
+
+ $url1_info = parse_url($url1);
+ $url2_info = parse_url($url2);
+
+ if (isset($url1_info['path'])) {
+ $url1_info['path'] = trim($url1_info['path'], '/');
+ }
+ if (isset($url2_info['path'])) {
+ $url2_info['path'] = trim($url2_info['path'], '/');
+ }
+
+ // compare basic bits
+ $parts = array('scheme', 'host', 'path');
+
+ foreach ($parts as $part) {
+ if ((isset($url1_info[$part]) && isset($url2_info[$part]))
+ && $url1_info[$part] != $url2_info[$part]) {
+ return FALSE;
+ } elseif (isset($url1_info[$part]) && !isset($url2_info[$part])) {
+ return FALSE;
+ } elseif (!isset($url1_info[$part]) && isset($url2_info[$part])) {
+ return FALSE;
+ }
+ }
+
+ // quick compare of get params
+ if (isset($url1_info['query']) && isset($url2_info['query'])
+ && $url1_info['query'] == $url2_info['query']) {
+ return TRUE;
+ }
+
+ // compare get params that might be out of order
+ $url1_params = array();
+ $url2_params = array();
+
+ if (isset($url1_info['query'])) {
+ if ($url1_info['query'] = html_entity_decode($url1_info['query'])) {
+ $url1_params = elgg_parse_str($url1_info['query']);
+ }
+ }
+
+ if (isset($url2_info['query'])) {
+ if ($url2_info['query'] = html_entity_decode($url2_info['query'])) {
+ $url2_params = elgg_parse_str($url2_info['query']);
+ }
+ }
+
+ // drop ignored params
+ foreach ($ignore_params as $param) {
+ if (isset($url1_params[$param])) {
+ unset($url1_params[$param]);
+ }
+ if (isset($url2_params[$param])) {
+ unset($url2_params[$param]);
+ }
+ }
+
+ // array_diff_assoc only returns the items in arr1 that aren't in arrN
+ // but not the items that ARE in arrN but NOT in arr1
+ // if arr1 is an empty array, this function will return 0 no matter what.
+ // since we only care if they're different and not how different,
+ // add the results together to get a non-zero (ie, different) result
+ $diff_count = count(array_diff_assoc($url1_params, $url2_params));
+ $diff_count += count(array_diff_assoc($url2_params, $url1_params));
+ if ($diff_count > 0) {
+ return FALSE;
+ }
+
+ return TRUE;
+}
+
+/**
+ * Checks for $array[$key] and returns its value if it exists, else
+ * returns $default.
+ *
+ * Shorthand for $value = (isset($array['key'])) ? $array['key'] : 'default';
+ *
+ * @param string $key The key to check.
+ * @param array $array The array to check against.
+ * @param mixed $default Default value to return if nothing is found.
+ * @param bool $strict Return array key if it's set, even if empty. If false,
+ * return $default if the array key is unset or empty.
+ *
+ * @return mixed
+ * @since 1.8.0
+ */
+function elgg_extract($key, array $array, $default = null, $strict = true) {
+ if (!is_array($array)) {
+ return $default;
+ }
+
+ if ($strict) {
+ return (isset($array[$key])) ? $array[$key] : $default;
+ } else {
+ return (isset($array[$key]) && !empty($array[$key])) ? $array[$key] : $default;
+ }
+}
+
+/**
+ * Sorts a 3d array by specific element.
+ *
+ * @warning Will re-index numeric indexes.
+ *
+ * @note This operates the same as the built-in sort functions.
+ * It sorts the array and returns a bool for success.
+ *
+ * Do this: elgg_sort_3d_array_by_value($my_array);
+ * Not this: $my_array = elgg_sort_3d_array_by_value($my_array);
+ *
+ * @param array &$array Array to sort
+ * @param string $element Element to sort by
+ * @param int $sort_order PHP sort order
+ * {@see http://us2.php.net/array_multisort}
+ * @param int $sort_type PHP sort type
+ * {@see http://us2.php.net/sort}
+ *
+ * @return bool
+ */
+function elgg_sort_3d_array_by_value(&$array, $element, $sort_order = SORT_ASC,
+$sort_type = SORT_LOCALE_STRING) {
+
+ $sort = array();
+
+ foreach ($array as $v) {
+ if (isset($v[$element])) {
+ $sort[] = strtolower($v[$element]);
+ } else {
+ $sort[] = NULL;
+ }
+ };
+
+ return array_multisort($sort, $sort_order, $sort_type, $array);
+}
+
+/**
+ * Return the state of a php.ini setting as a bool
+ *
+ * @warning Using this on ini settings that are not boolean
+ * will be inaccurate!
+ *
+ * @param string $ini_get_arg The INI setting
+ *
+ * @return bool Depending on whether it's on or off
+ */
+function ini_get_bool($ini_get_arg) {
+ $temp = strtolower(ini_get($ini_get_arg));
+
+ if ($temp == '1' || $temp == 'on' || $temp == 'true') {
+ return true;
+ }
+ return false;
+}
+
+/**
+ * Returns a PHP INI setting in bytes.
+ *
+ * @tip Use this for arithmetic when determining if a file can be uploaded.
+ *
+ * @param string $setting The php.ini setting
+ *
+ * @return int
+ * @since 1.7.0
+ * @link http://www.php.net/manual/en/function.ini-get.php
+ */
+function elgg_get_ini_setting_in_bytes($setting) {
+ // retrieve INI setting
+ $val = ini_get($setting);
+
+ // convert INI setting when shorthand notation is used
+ $last = strtolower($val[strlen($val) - 1]);
+ switch($last) {
+ case 'g':
+ $val *= 1024;
+ // fallthrough intentional
+ case 'm':
+ $val *= 1024;
+ // fallthrough intentional
+ case 'k':
+ $val *= 1024;
+ }
+
+ // return byte value
+ return $val;
+}
+
+/**
+ * Returns true is string is not empty, false, or null.
+ *
+ * Function to be used in array_filter which returns true if $string is not null.
+ *
+ * @param string $string The string to test
+ *
+ * @return bool
+ * @todo This is used once in metadata.php. Use a lambda function instead.
+ */
+function is_not_null($string) {
+ if (($string === '') || ($string === false) || ($string === null)) {
+ return false;
+ }
+
+ return true;
+}
+
+/**
+ * Normalise the singular keys in an options array to plural keys.
+ *
+ * Used in elgg_get_entities*() functions to support shortcutting plural
+ * names by singular names.
+ *
+ * @param array $options The options array. $options['keys'] = 'values';
+ * @param array $singulars A list of singular words to pluralize by adding 's'.
+ *
+ * @return array
+ * @since 1.7.0
+ * @access private
+ */
+function elgg_normalise_plural_options_array($options, $singulars) {
+ foreach ($singulars as $singular) {
+ $plural = $singular . 's';
+
+ if (array_key_exists($singular, $options)) {
+ if ($options[$singular] === ELGG_ENTITIES_ANY_VALUE) {
+ $options[$plural] = $options[$singular];
+ } else {
+ // Test for array refs #2641
+ if (!is_array($options[$singular])) {
+ $options[$plural] = array($options[$singular]);
+ } else {
+ $options[$plural] = $options[$singular];
+ }
+ }
+ }
+
+ unset($options[$singular]);
+ }
+
+ return $options;
+}
+
+/**
+ * Emits a shutdown:system event upon PHP shutdown, but before database connections are dropped.
+ *
+ * @tip Register for the shutdown:system event to perform functions at the end of page loads.
+ *
+ * @warning Using this event to perform long-running functions is not very
+ * useful. Servers will hold pages until processing is done before sending
+ * them out to the browser.
+ *
+ * @see http://www.php.net/register-shutdown-function
+ *
+ * @return void
+ * @see register_shutdown_hook()
+ * @access private
+ */
+function _elgg_shutdown_hook() {
+ global $START_MICROTIME;
+
+ try {
+ elgg_trigger_event('shutdown', 'system');
+
+ $time = (float)(microtime(TRUE) - $START_MICROTIME);
+ // demoted to NOTICE from DEBUG so javascript is not corrupted
+ elgg_log("Page {$_SERVER['REQUEST_URI']} generated in $time seconds", 'NOTICE');
+ } catch (Exception $e) {
+ $message = 'Error: ' . get_class($e) . ' thrown within the shutdown handler. ';
+ $message .= "Message: '{$e->getMessage()}' in file {$e->getFile()} (line {$e->getLine()})";
+ error_log($message);
+ error_log("Exception trace stack: {$e->getTraceAsString()}");
+ }
+}
+
+/**
+ * Serve javascript pages.
+ *
+ * Searches for views under js/ and outputs them with special
+ * headers for caching control.
+ *
+ * @param array $page The page array
+ *
+ * @return bool
+ * @elgg_pagehandler js
+ * @access private
+ */
+function elgg_js_page_handler($page) {
+ return elgg_cacheable_view_page_handler($page, 'js');
+}
+
+/**
+ * Serve individual views for Ajax.
+ *
+ * /ajax/view/<name of view>?<key/value params>
+ *
+ * @param array $page The page array
+ *
+ * @return bool
+ * @elgg_pagehandler ajax
+ * @access private
+ */
+function elgg_ajax_page_handler($page) {
+ if (is_array($page) && sizeof($page)) {
+ // throw away 'view' and form the view name
+ unset($page[0]);
+ $view = implode('/', $page);
+
+ $allowed_views = elgg_get_config('allowed_ajax_views');
+ if (!array_key_exists($view, $allowed_views)) {
+ header('HTTP/1.1 403 Forbidden');
+ exit;
+ }
+
+ // pull out GET parameters through filter
+ $vars = array();
+ foreach ($_GET as $name => $value) {
+ $vars[$name] = get_input($name);
+ }
+
+ if (isset($vars['guid'])) {
+ $vars['entity'] = get_entity($vars['guid']);
+ }
+
+ echo elgg_view($view, $vars);
+ return true;
+ }
+ return false;
+}
+
+/**
+ * Serve CSS
+ *
+ * Serves CSS from the css views directory with headers for caching control
+ *
+ * @param array $page The page array
+ *
+ * @return bool
+ * @elgg_pagehandler css
+ * @access private
+ */
+function elgg_css_page_handler($page) {
+ if (!isset($page[0])) {
+ // default css
+ $page[0] = 'elgg';
+ }
+
+ return elgg_cacheable_view_page_handler($page, 'css');
+}
+
+/**
+ * Serves a JS or CSS view with headers for caching.
+ *
+ * /<css||js>/name/of/view.<last_cache>.<css||js>
+ *
+ * @param array $page The page array
+ * @param string $type The type: js or css
+ *
+ * @return bool
+ * @access private
+ */
+function elgg_cacheable_view_page_handler($page, $type) {
+
+ switch ($type) {
+ case 'js':
+ $content_type = 'text/javascript';
+ break;
+
+ case 'css':
+ $content_type = 'text/css';
+ break;
+
+ default:
+ return false;
+ break;
+ }
+
+ if ($page) {
+ // the view file names can have multiple dots
+ // eg: views/default/js/calendars/jquery.fullcalendar.min.php
+ // translates to the url /js/calendars/jquery.fullcalendar.min.<ts>.js
+ // and the view js/calendars/jquery.fullcalendar.min
+ // we ignore the last two dots for the ts and the ext.
+ // Additionally, the timestamp is optional.
+ $page = implode('/', $page);
+ $regex = '|(.+?)\.([\d]+\.)?\w+$|';
+ preg_match($regex, $page, $matches);
+ $view = $matches[1];
+ $return = elgg_view("$type/$view");
+
+ header("Content-type: $content_type");
+
+ // @todo should js be cached when simple cache turned off
+ //header('Expires: ' . gmdate('D, d M Y H:i:s \G\M\T', strtotime("+10 days")), true);
+ //header("Pragma: public");
+ //header("Cache-Control: public");
+ //header("Content-Length: " . strlen($return));
+
+ echo $return;
+ return true;
+ }
+ return false;
+}
+
+/**
+ * Reverses the ordering in an ORDER BY clause. This is achived by replacing
+ * asc with desc, or appending desc to the end of the clause.
+ *
+ * This is used mostly for elgg_get_entities() and other similar functions.
+ *
+ * @param string $order_by An order by clause
+ * @access private
+ * @return string
+ * @access private
+ */
+function elgg_sql_reverse_order_by_clause($order_by) {
+ $order_by = strtolower($order_by);
+
+ if (strpos($order_by, ' asc') !== false) {
+ $return = str_replace(' asc', ' desc', $order_by);
+ } elseif (strpos($order_by, ' desc') !== false) {
+ $return = str_replace(' desc', ' asc', $order_by);
+ } else {
+ // no order specified, so default to desc since mysql defaults to asc
+ $return = $order_by . ' desc';
+ }
+
+ return $return;
+}
+
+/**
+ * Enable objects with an enable() method.
+ *
+ * Used as a callback for ElggBatch.
+ *
+ * @todo why aren't these static methods on ElggBatch?
+ *
+ * @param object $object The object to enable
+ * @return bool
+ * @access private
+ */
+function elgg_batch_enable_callback($object) {
+ // our db functions return the number of rows affected...
+ return $object->enable() ? true : false;
+}
+
+/**
+ * Disable objects with a disable() method.
+ *
+ * Used as a callback for ElggBatch.
+ *
+ * @param object $object The object to disable
+ * @return bool
+ * @access private
+ */
+function elgg_batch_disable_callback($object) {
+ // our db functions return the number of rows affected...
+ return $object->disable() ? true : false;
+}
+
+/**
+ * Delete objects with a delete() method.
+ *
+ * Used as a callback for ElggBatch.
+ *
+ * @param object $object The object to disable
+ * @return bool
+ * @access private
+ */
+function elgg_batch_delete_callback($object) {
+ // our db functions return the number of rows affected...
+ return $object->delete() ? true : false;
+}
+
+/**
+ * Checks if there are some constraints on the options array for
+ * potentially dangerous operations.
+ *
+ * @param array $options Options array
+ * @param string $type Options type: metadata or annotations
+ * @return bool
+ * @access private
+ */
+function elgg_is_valid_options_for_batch_operation($options, $type) {
+ if (!$options || !is_array($options)) {
+ return false;
+ }
+
+ // at least one of these is required.
+ $required = array(
+ // generic restraints
+ 'guid', 'guids'
+ );
+
+ switch ($type) {
+ case 'metadata':
+ $metadata_required = array(
+ 'metadata_owner_guid', 'metadata_owner_guids',
+ 'metadata_name', 'metadata_names',
+ 'metadata_value', 'metadata_values'
+ );
+
+ $required = array_merge($required, $metadata_required);
+ break;
+
+ case 'annotations':
+ case 'annotation':
+ $annotations_required = array(
+ 'annotation_owner_guid', 'annotation_owner_guids',
+ 'annotation_name', 'annotation_names',
+ 'annotation_value', 'annotation_values'
+ );
+
+ $required = array_merge($required, $annotations_required);
+ break;
+
+ default:
+ return false;
+ }
+
+ foreach ($required as $key) {
+ // check that it exists and is something.
+ if (isset($options[$key]) && $options[$key]) {
+ return true;
+ }
+ }
+
+ return false;
+}
+
+/**
+ * Intercepts the index page when Walled Garden mode is enabled.
+ *
+ * @link http://docs.elgg.org/Tutorials/WalledGarden
+ * @elgg_plugin_hook index system
+ *
+ * @param string $hook The name of the hook
+ * @param string $type The type of hook
+ * @param bool $value Has a plugin already rendered an index page?
+ * @param array $params Array of parameters (should be empty)
+ * @return bool
+ * @access private
+ */
+function elgg_walled_garden_index($hook, $type, $value, $params) {
+ if ($value) {
+ // do not create a second index page so return
+ return;
+ }
+
+ elgg_load_css('elgg.walled_garden');
+ elgg_load_js('elgg.walled_garden');
+
+ $content = elgg_view('core/walled_garden/login');
+
+ $params = array(
+ 'content' => $content,
+ 'class' => 'elgg-walledgarden-double',
+ 'id' => 'elgg-walledgarden-login',
+ );
+ $body = elgg_view_layout('walled_garden', $params);
+ echo elgg_view_page('', $body, 'walled_garden');
+
+ // return true to prevent other plugins from adding a front page
+ return true;
+}
+
+/**
+ * Serve walled garden sections
+ *
+ * @param array $page Array of URL segments
+ * @return string
+ * @access private
+ */
+function _elgg_walled_garden_ajax_handler($page) {
+ $view = $page[0];
+ $params = array(
+ 'content' => elgg_view("core/walled_garden/$view"),
+ 'class' => 'elgg-walledgarden-single hidden',
+ 'id' => str_replace('_', '-', "elgg-walledgarden-$view"),
+ );
+ echo elgg_view_layout('walled_garden', $params);
+ return true;
+}
+
+/**
+ * Checks the status of the Walled Garden and forwards to a login page
+ * if required.
+ *
+ * If the site is in Walled Garden mode, all page except those registered as
+ * plugin pages by {@elgg_hook public_pages walled_garden} will redirect to
+ * a login page.
+ *
+ * @since 1.8.0
+ * @elgg_event_handler init system
+ * @link http://docs.elgg.org/Tutorials/WalledGarden
+ * @return void
+ * @access private
+ */
+function elgg_walled_garden() {
+ global $CONFIG;
+
+ elgg_register_css('elgg.walled_garden', '/css/walled_garden.css');
+ elgg_register_js('elgg.walled_garden', '/js/walled_garden.js');
+
+ elgg_register_page_handler('walled_garden', '_elgg_walled_garden_ajax_handler');
+
+ // check for external page view
+ if (isset($CONFIG->site) && $CONFIG->site instanceof ElggSite) {
+ $CONFIG->site->checkWalledGarden();
+ }
+}
+
+/**
+ * Remove public access for walled gardens
+ *
+ * @param string $hook
+ * @param string $type
+ * @param array $accesses
+ * @return array
+ * @access private
+ */
+function _elgg_walled_garden_remove_public_access($hook, $type, $accesses) {
+ if (isset($accesses[ACCESS_PUBLIC])) {
+ unset($accesses[ACCESS_PUBLIC]);
+ }
+ return $accesses;
+}
+
+/**
+ * Boots the engine
+ *
+ * 1. sets error handlers
+ * 2. connects to database
+ * 3. verifies the installation suceeded
+ * 4. loads application configuration
+ * 5. loads i18n data
+ * 6. loads site configuration
+ *
+ * @access private
+ */
+function _elgg_engine_boot() {
+ // Register the error handlers
+ set_error_handler('_elgg_php_error_handler');
+ set_exception_handler('_elgg_php_exception_handler');
+
+ setup_db_connections();
+
+ verify_installation();
+
+ _elgg_load_application_config();
+
+ _elgg_load_site_config();
+
+ _elgg_session_boot();
+
+ _elgg_load_cache();
+
+ _elgg_load_translations();
+}
+
+/**
+ * Elgg's main init.
+ *
+ * Handles core actions for comments, the JS pagehandler, and the shutdown function.
+ *
+ * @elgg_event_handler init system
+ * @return void
+ * @access private
+ */
+function elgg_init() {
+ global $CONFIG;
+
+ elgg_register_action('comments/add');
+ elgg_register_action('comments/delete');
+
+ elgg_register_page_handler('js', 'elgg_js_page_handler');
+ elgg_register_page_handler('css', 'elgg_css_page_handler');
+ elgg_register_page_handler('ajax', 'elgg_ajax_page_handler');
+
+ elgg_register_js('elgg.autocomplete', 'js/lib/ui.autocomplete.js');
+ elgg_register_js('jquery.ui.autocomplete.html', 'vendors/jquery/jquery.ui.autocomplete.html.js');
+ elgg_register_js('elgg.userpicker', 'js/lib/ui.userpicker.js');
+ elgg_register_js('elgg.friendspicker', 'js/lib/ui.friends_picker.js');
+ elgg_register_js('jquery.easing', 'vendors/jquery/jquery.easing.1.3.packed.js');
+ elgg_register_js('elgg.avatar_cropper', 'js/lib/ui.avatar_cropper.js');
+ elgg_register_js('jquery.imgareaselect', 'vendors/jquery/jquery.imgareaselect-0.9.8/scripts/jquery.imgareaselect.min.js');
+ elgg_register_js('elgg.ui.river', 'js/lib/ui.river.js');
+
+ elgg_register_css('jquery.imgareaselect', 'vendors/jquery/jquery.imgareaselect-0.9.8/css/imgareaselect-deprecated.css');
+
+ // Trigger the shutdown:system event upon PHP shutdown.
+ register_shutdown_function('_elgg_shutdown_hook');
+
+ $logo_url = elgg_get_site_url() . "_graphics/elgg_toolbar_logo.gif";
+ elgg_register_menu_item('topbar', array(
+ 'name' => 'elgg_logo',
+ 'href' => 'http://www.elgg.org/',
+ 'text' => "<img src=\"$logo_url\" alt=\"Elgg logo\" width=\"38\" height=\"20\" />",
+ 'priority' => 1,
+ 'link_class' => 'elgg-topbar-logo',
+ ));
+
+ // Sets a blacklist of words in the current language.
+ // This is a comma separated list in word:blacklist.
+ // @todo possibly deprecate
+ $CONFIG->wordblacklist = array();
+ $list = explode(',', elgg_echo('word:blacklist'));
+ if ($list) {
+ foreach ($list as $l) {
+ $CONFIG->wordblacklist[] = trim($l);
+ }
+ }
+}
+
+/**
+ * Adds unit tests for the general API.
+ *
+ * @param string $hook unit_test
+ * @param string $type system
+ * @param array $value array of test files
+ * @param array $params empty
+ *
+ * @elgg_plugin_hook unit_tests system
+ * @return array
+ * @access private
+ */
+function elgg_api_test($hook, $type, $value, $params) {
+ global $CONFIG;
+ $value[] = $CONFIG->path . 'engine/tests/api/entity_getter_functions.php';
+ $value[] = $CONFIG->path . 'engine/tests/api/helpers.php';
+ $value[] = $CONFIG->path . 'engine/tests/regression/trac_bugs.php';
+ return $value;
+}
+
+/**#@+
+ * Controls access levels on ElggEntity entities, metadata, and annotations.
+ *
+ * @warning ACCESS_DEFAULT is a place holder for the input/access view. Do not
+ * use it when saving an entity.
+ *
+ * @var int
+ */
+define('ACCESS_DEFAULT', -1);
+define('ACCESS_PRIVATE', 0);
+define('ACCESS_LOGGED_IN', 1);
+define('ACCESS_PUBLIC', 2);
+define('ACCESS_FRIENDS', -2);
+/**#@-*/
+
+/**
+ * Constant to request the value of a parameter be ignored in elgg_get_*() functions
+ *
+ * @see elgg_get_entities()
+ * @var NULL
+ * @since 1.7
+ */
+define('ELGG_ENTITIES_ANY_VALUE', NULL);
+
+/**
+ * Constant to request the value of a parameter be nothing in elgg_get_*() functions.
+ *
+ * @see elgg_get_entities()
+ * @var int 0
+ * @since 1.7
+ */
+define('ELGG_ENTITIES_NO_VALUE', 0);
+
+/**
+ * Used in calls to forward() to specify the browser should be redirected to the
+ * referring page.
+ *
+ * @see forward
+ * @var int -1
+ */
+define('REFERRER', -1);
+
+/**
+ * Alternate spelling for REFERRER. Included because of some bad documentation
+ * in the original HTTP spec.
+ *
+ * @see forward()
+ * @link http://en.wikipedia.org/wiki/HTTP_referrer#Origin_of_the_term_referer
+ * @var int -1
+ */
+define('REFERER', -1);
+
+elgg_register_event_handler('init', 'system', 'elgg_init');
+elgg_register_event_handler('boot', 'system', '_elgg_engine_boot', 1);
+elgg_register_plugin_hook_handler('unit_test', 'system', 'elgg_api_test');
+
+elgg_register_event_handler('init', 'system', 'add_custom_menu_items', 1000);
+elgg_register_event_handler('init', 'system', 'elgg_walled_garden', 1000);