Implemented blocking of YouTube video ads, by rewriting flashvars, for Safari

safari/include.youtube.js

Index: safari/include.youtube.js
===================================================================
new file mode 100644
--- /dev/null
+++ b/safari/include.youtube.js
@@ -0,0 +1,91 @@
+/*
+ * This file is part of Adblock Plus <http://adblockplus.org/>,
+ * Copyright (C) 2006-2013 Eyeo GmbH
+ *
+ * Adblock Plus is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 3 as
+ * published by the Free Software Foundation.
+ *
+ * Adblock Plus is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+(function() {
+  if (document.domain != "www.youtube.com")
+    return;
+
+  function rewriteFlashvars(flashvars)
+  {
+    var pairs = flashvars.split("&");
+    for (var i = 0; i < pairs.length; i++)
+      if (/^((ad|afv|adsense|iv)(_.*)?|(ad3|iv3|st)_module|prerolls|interstitial|infringe|invideo)=/.test(pairs[i]))
+        pairs.splice(i--, 1);
+    return pairs.join("&");
+  }
+
+  function patchPlayer(player) 
+  {
+    var newPlayer = player.cloneNode(true);
+    var flashvarsChanged = false;
+
+    var flashvars = newPlayer.getAttribute("flashvars");
+    if (flashvars)
+    {
+      var newFlashvars = rewriteFlashvars(flashvars);
+      if (flashvars != newFlashvars)
+      {
+        newPlayer.setAttribute("flashvars", newFlashvars);
+        flashvarsChanged = true;
+      }
+    }
+
+    var param = newPlayer.querySelector("param[name=flashvars]");
+    if (param)
+    {
+      var value = param.getAttribute("value");
+      if (value)
+      {
+        var newValue = rewriteFlashvars(value);
+        if (value != newValue)
+        {
+          param.setAttribute("value", newValue);
+          flashvarsChanged = true;
+        }
+      }
+    }
+
+    if (flashvarsChanged)
+      player.parentNode.replaceChild(newPlayer, player);
+  }
+
+  var deferred = [];
+  function patchPlayerDeferred(player)
+  {
+    deferred.push(player);
+  }
+
+  var onBeforeLoadYoutubeVideo = patchPlayerDeferred;
+  function onBeforeLoad(event)
+  {
+    if ((event.target.localName == "object" || event.target.localName == "embed") && /:\/\/[^\/]*\.ytimg\.com\//.test(event.url))
+      onBeforeLoadYoutubeVideo(event.target);
+  }
+
+  ext.backgroundPage.sendMessage({type: "get-domain-enabled-state"}, function(response)
+  {
+    if (response.enabled)
+    {
+      deferred.forEach(patchPlayer);
+      onBeforeLoadYoutubeVideo = patchPlayer;
+    }
+    else
+      document.removeEventListener("beforeload", onBeforeLoad);
+  });
+
+  document.addEventListener("beforeload", onBeforeLoad, true);
+})();