From 04a1021425e0b9a88c1b7c205a525982472170bc Mon Sep 17 00:00:00 2001
From: bsitu <bsitu@wikimedia.org>
Date: Tue, 3 Sep 2013 13:43:40 -0700
Subject: [PATCH] Add a deferrable update class for callback/closure udpates

Change-Id: Ifdf2a0937df50eb2f04d514b5cc2ef39a54ebe8f
---
 RELEASE-NOTES-1.22           |  1 +
 includes/AutoLoader.php      |  1 +
 includes/CallableUpdate.php  | 30 ++++++++++++++++++++++++++++++
 includes/DeferredUpdates.php | 10 ++++++++++
 4 files changed, 42 insertions(+)
 create mode 100644 includes/CallableUpdate.php

diff --git a/RELEASE-NOTES-1.22 b/RELEASE-NOTES-1.22
index b88e323dd4..24aaceb6a4 100644
--- a/RELEASE-NOTES-1.22
+++ b/RELEASE-NOTES-1.22
@@ -208,6 +208,7 @@ production.
   and Special:AllMyUploads respectively.
 * IPv6 addresses in X-Forwarded-For headers are now normalised before checking
   against allowed proxy lists.
+* Add deferrable update support for callback/closure
 
 === Bug fixes in 1.22 ===
 * Disable Special:PasswordReset when $wgEnableEmail is false. Previously one
diff --git a/includes/AutoLoader.php b/includes/AutoLoader.php
index 82d204b138..677bed3f31 100644
--- a/includes/AutoLoader.php
+++ b/includes/AutoLoader.php
@@ -68,6 +68,7 @@ $wgAutoloadLocalClasses = array(
 	'CurlHttpRequest' => 'includes/HttpFunctions.php',
 	'DeferrableUpdate' => 'includes/DeferredUpdates.php',
 	'DeferredUpdates' => 'includes/DeferredUpdates.php',
+	'MWCallableUpdate' => 'includes/CallableUpdate.php',
 	'DeprecatedGlobal' => 'includes/DeprecatedGlobal.php',
 	'DerivativeRequest' => 'includes/WebRequest.php',
 	'DiffHistoryBlob' => 'includes/HistoryBlob.php',
diff --git a/includes/CallableUpdate.php b/includes/CallableUpdate.php
new file mode 100644
index 0000000000..6eb5541393
--- /dev/null
+++ b/includes/CallableUpdate.php
@@ -0,0 +1,30 @@
+<?php
+
+/**
+ * Deferrable Update for closure/callback
+ */
+class MWCallableUpdate implements DeferrableUpdate {
+
+	/**
+	 * @var closure/callabck
+	 */
+	private $callback;
+
+	/**
+	 * @param callable $callback
+	 */
+	public function __construct( $callback ) {
+		if ( !is_callable( $callback ) ) {
+			throw new MWException( 'Not a valid callback/closure!' );
+		}
+		$this->callback = $callback;
+	}
+
+	/**
+	 * Run the update
+	 */
+	public function doUpdate() {
+		call_user_func( $this->callback );
+	}
+
+}
diff --git a/includes/DeferredUpdates.php b/includes/DeferredUpdates.php
index 89c4df68f8..a321414ae5 100644
--- a/includes/DeferredUpdates.php
+++ b/includes/DeferredUpdates.php
@@ -63,6 +63,16 @@ class DeferredUpdates {
 		self::addUpdate( new HTMLCacheUpdate( $title, $table ) );
 	}
 
+	/**
+	 * Add a callable update.  In a lot of cases, we just need a callback/closure,
+	 * defining a new DeferrableUpdate object is not necessary
+	 * @see MWCallableUpdate::__construct()
+	 * @param callable $callable
+	 */
+	public static function addCallableUpdate( $callable ) {
+		self::addUpdate( new MWCallableUpdate( $callable ) );
+	}
+
 	/**
 	 * Do any deferred updates and clear the list
 	 *
-- 
2.20.1