Issue 3851 - Implement subscribe link handling via process scripts

lib/child/subscribeLinks.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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()
+let {Services} = Cu.import("resource://gre/modules/Services.jsm", {});
+
+let {port} = require("messaging");
+
+Services.obs.addObserver(onContentWindow, "content-document-global-created",
+    false);
+onShutdown.add(() =>
 {
-  addEventListener("click", onClick, false);
-  addMessageListener("AdblockPlus:Shutdown", onShutdown);
+  Services.obs.removeObserver(onContentWindow,
+      "content-document-global-created");
+});
 
-  function onShutdown(message)
+function onContentWindow(subject, topic, data)
+{
+  if (subject instanceof Ci.nsIDOMWindow && subject.top == subject)

[Thomas Greiner, 2016/04/18 15:16:25]

So we're not listening to clicks in subdocuments?

[Wladimir Palant, 2016/04/18 15:38:40]

We do, clicks will bubble up from frames. I verified that.

[Thomas Greiner, 2016/04/18 17:49:43]

Thanks for verifying!

   {
-    if (message.data == Components.stack.filename)
+    let eventTarget = subject.QueryInterface(Ci.nsIInterfaceRequestor)
+                             .getInterface(Ci.nsIWebNavigation)
+                             .QueryInterface(Ci.nsIDocShell)
+                             .chromeEventHandler;
+    eventTarget.addEventListener("click", onClick, true);
+  }
+}
+
+function onClick(event)

[Wladimir Palant, 2016/03/21 19:27:20]

It's mostly an indentation change for this function. The only changes are
onShutdown.done check at the beginning and `link instanceof
content.HTMLAnchorElement` => `link instanceof Ci.nsIDOMHTMLAnchorElement` a bit
further down.

[Wladimir Palant, 2016/03/21 19:29:20]

Heh, forgot the sendAsyncMessage call at the bottom, it has been replaced by
port.emit.

+{
+  if (onShutdown.done)
+    return;

[Erik, 2016/04/06 03:11:41]

This will stop the function from running after shutdown, but the function is
leaked if it runs after shutdown right?

[Wladimir Palant, 2016/04/18 15:38:40]

Yes, the function itself is leaked - getting the event handler removed after
shutdown would be rather tricky.

+
+  // Ignore right-clicks
+  if (event.button == 2)
+    return;
+
+  // Search the link associated with the click
+  let link = event.target;
+  while (!(link instanceof Ci.nsIDOMHTMLAnchorElement))
+  {
+    link = link.parentNode;
+
+    if (!link)
+      return;
+  }
+
+  let queryString = null;
+  if (link.protocol == "http:" || link.protocol == "https:")
+  {
+    if (link.host == "subscribe.adblockplus.org" && link.pathname == "/")
+      queryString = link.search.substr(1);
+  }
+  else
+  {
+    // Firefox doesn't populate the "search" property for links with
+    // non-standard URL schemes so we need to extract the query string
+    // manually
+    let match = /^abp:\/*subscribe\/*\?(.*)/i.exec(link.href);
+    if (match)
+      queryString = match[1];
+  }
+
+  if (!queryString)
+    return;
+
+  // This is our link - make sure the browser doesn't handle it
+  event.preventDefault();
+  event.stopPropagation();
+
+  // Decode URL parameters
+  let title = null;
+  let url = null;
+  let mainSubscriptionTitle = null;
+  let mainSubscriptionURL = null;
+  for (let param of queryString.split("&"))
+  {
+    let parts = param.split("=", 2);
+    if (parts.length != 2 || !/\S/.test(parts[1]))
+      continue;
+    switch (parts[0])
     {
-      removeEventListener("click", onClick, false);
-      removeMessageListener("AdblockPlus:Shutdown", onShutdown);
+      case "title":
+        title = decodeURIComponent(parts[1]);
+        break;
+      case "location":
+        url = decodeURIComponent(parts[1]);
+        break;
+      case "requiresTitle":
+        mainSubscriptionTitle = decodeURIComponent(parts[1]);
+        break;
+      case "requiresLocation":
+        mainSubscriptionURL = decodeURIComponent(parts[1]);
+        break;
     }
   }
 
-  function onClick(event)
-  {
-    // Ignore right-clicks
-    if (event.button == 2)
-      return;
-
-    // Search the link associated with the click
-    let link = event.target;
-    while (!(link instanceof content.HTMLAnchorElement))
-    {
-      link = link.parentNode;
-
-      if (!link)
-        return;
-    }
-
-    let queryString = null;
-    if (link.protocol == "http:" || link.protocol == "https:")
-    {
-      if (link.host == "subscribe.adblockplus.org" && link.pathname == "/")
-        queryString = link.search.substr(1);
-    }
-    else
-    {
-      // Firefox doesn't populate the "search" property for links with
-      // non-standard URL schemes so we need to extract the query string
-      // manually
-      let match = /^abp:\/*subscribe\/*\?(.*)/i.exec(link.href);
-      if (match)
-        queryString = match[1];
-    }
-
-    if (!queryString)
-      return;
-
-    // This is our link - make sure the browser doesn't handle it
-    event.preventDefault();
-    event.stopPropagation();
-
-    // Decode URL parameters
-    let title = null;
-    let url = null;
-    let mainSubscriptionTitle = null;
-    let mainSubscriptionURL = null;
-    for (let param of queryString.split("&"))
-    {
-      let parts = param.split("=", 2);
-      if (parts.length != 2 || !/\S/.test(parts[1]))
-        continue;
-      switch (parts[0])
-      {
-        case "title":
-          title = decodeURIComponent(parts[1]);
-          break;
-        case "location":
-          url = decodeURIComponent(parts[1]);
-          break;
-        case "requiresTitle":
-          mainSubscriptionTitle = decodeURIComponent(parts[1]);
-          break;
-        case "requiresLocation":
-          mainSubscriptionURL = decodeURIComponent(parts[1]);
-          break;
-      }
-    }
-
-    sendAsyncMessage("AdblockPlus:SubscribeLink", {
-      title: title,
-      url: url,
-      mainSubscriptionTitle: mainSubscriptionTitle,
-      mainSubscriptionURL: mainSubscriptionURL
-    });
-  }
-})();
-
+  port.emit("subscribeLinkClick", {
+    title: title,
+    url: url,
+    mainSubscriptionTitle: mainSubscriptionTitle,
+    mainSubscriptionURL: mainSubscriptionURL
+  });
+}