1 files changed, 150 insertions, 0 deletions
diff --git a/engine/lib/pagehandler.php b/engine/lib/pagehandler.php
new file mode 100644
index 000000000..0cf99b6fe
--- /dev/null
+++ b/engine/lib/pagehandler.php
@@ -0,0 +1,150 @@
+<?php
+/**
+ * Elgg page handler functions
+ *
+ * @package Elgg.Core
+ * @subpackage Routing
+ */
+
+/**
+ * Routes the request to a registered page handler
+ *
+ * This function sets the context based on the handler name (first segment of the
+ * URL). It also triggers a plugin hook 'route', $handler so that plugins can
+ * modify the routing or handle a request.
+ *
+ * @param string $handler The name of the handler type (eg 'blog')
+ * @param array  $page    The parameters to the page, as an array (exploded by '/' slashes)
+ *
+ * @return bool
+ * @access private
+ */
+function page_handler($handler, $page) {
+	global $CONFIG;
+
+	elgg_set_context($handler);
+
+	$page = explode('/', $page);
+	// remove empty array element when page url ends in a / (see #1480)
+	if ($page[count($page) - 1] === '') {
+		array_pop($page);
+	}
+
+	// return false to stop processing the request (because you handled it)
+	// return a new $request array if you want to route the request differently
+	$request = array(
+		'handler' => $handler,
+		'segments' => $page,
+	);
+	$request = elgg_trigger_plugin_hook('route', $handler, null, $request);
+	if ($request === false) {
+		return true;
+	}
+
+	$handler = $request['handler'];
+	$page = $request['segments'];
+
+	$result = false;
+	if (isset($CONFIG->pagehandler)
+			&& !empty($handler)
+			&& isset($CONFIG->pagehandler[$handler])
+			&& is_callable($CONFIG->pagehandler[$handler])) {
+		$function = $CONFIG->pagehandler[$handler];
+		$result = call_user_func($function, $page, $handler);
+	}
+
+	return $result || headers_sent();
+}
+
+/**
+ * Registers a page handler for a particular identifier
+ *
+ * For example, you can register a function called 'blog_page_handler' for handler type 'blog'
+ * For all URLs  http://yoururl/blog/*, the blog_page_handler() function will be called.
+ * The part of the URL marked with * above will be exploded on '/' characters and passed as an
+ * array to that function.
+ * For example, the URL http://yoururl/blog/username/friends/ would result in the call:
+ * blog_page_handler(array('username','friends'), blog);
+ *
+ * A request to register a page handler with the same identifier as previously registered
+ * handler will replace the previous one.
+ *
+ * The context is set to the page handler identifier before the registered
+ * page handler function is called. For the above example, the context is set to 'blog'.
+ *
+ * Page handlers should return true to indicate that they handled the request.
+ * Requests not handled are forwarded to the front page with a reason of 404.
+ * Plugins can register for the 'forward', '404' plugin hook. @see forward()
+ *
+ * @param string $handler  The page type to handle
+ * @param string $function Your function name
+ *
+ * @return bool Depending on success
+ */
+function elgg_register_page_handler($handler, $function) {
+	global $CONFIG;
+
+	if (!isset($CONFIG->pagehandler)) {
+		$CONFIG->pagehandler = array();
+	}
+	if (is_callable($function, true)) {
+		$CONFIG->pagehandler[$handler] = $function;
+		return true;
+	}
+
+	return false;
+}
+
+/**
+ * Unregister a page handler for an identifier
+ *
+ * Note: to replace a page handler, call elgg_register_page_handler()
+ *
+ * @param string $handler The page type identifier
+ *
+ * @since 1.7.2
+ * @return void
+ */
+function elgg_unregister_page_handler($handler) {
+	global $CONFIG;
+
+	if (!isset($CONFIG->pagehandler)) {
+		return;
+	}
+
+	unset($CONFIG->pagehandler[$handler]);
+}
+
+/**
+ * Serve an error page
+ *
+ * @todo not sending status codes yet
+ *
+ * @param string $hook   The name of the hook
+ * @param string $type   The type of the hook
+ * @param bool   $result The current value of the hook
+ * @param array  $params Parameters related to the hook
+ * @return void
+ */
+function elgg_error_page_handler($hook, $type, $result, $params) {
+	if (elgg_view_exists("errors/$type")) {
+		$content = elgg_view("errors/$type", $params);
+	} else {
+		$content = elgg_view("errors/default", $params);
+	}
+	$body = elgg_view_layout('error', array('content' => $content));
+	echo elgg_view_page('', $body, 'error');
+	exit;
+}
+
+/**
+ * Initializes the page handler/routing system
+ *
+ * @return void
+ * @access private
+ */
+function page_handler_init() {
+	elgg_register_plugin_hook_handler('forward', '404', 'elgg_error_page_handler');
+}
+
+elgg_register_event_handler('init', 'system', 'page_handler_init');