From 5175c992803297edf8c7acd5faaba0aa38c5be8b Mon Sep 17 00:00:00 2001
From: Antonio Ospite <ospite@studenti.unina.it>
Date: Sun, 12 Feb 2012 16:45:40 +0100
Subject: [PATCH 1/1] Use XPath to find the elements of interest

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
---
 direct_download_links.user.js | 38 +++++++++++++++++++++-----------------
 1 file changed, 21 insertions(+), 17 deletions(-)

diff --git a/direct_download_links.user.js b/direct_download_links.user.js
index 8421b49..9344012 100644
--- a/direct_download_links.user.js
+++ b/direct_download_links.user.js
@@ -37,7 +37,6 @@
  *  - find a way to use the same string as in the @include lines to match the
  *    current window.location. Look for something like GM_testUrl() which builds
  *    the regexp starting from a glob line.
- *  - use xpath instead of regexp like in http://a32.me/2009/11/greasemonkey/
  *  - use jquery, like shown in http://a32.me/2009/11/greasemonkey/
  *  - Support the "download" attribute for anchors:
  *    http://www.whatwg.org/specs/web-apps/current-work/multipage/links.html#downloading-resources
@@ -47,10 +46,10 @@
  *
  * Manadatory fields:
  *   locationRegExp: the regexp describing the URL of the page we are modifying
- *   urlContainer: the element containing the URL to link
+ *   urlContainerXPath: the XPath of the element containing the URL to link
  *   urlRegexp: the regular expression for finding the URL, the first
  *              sub-pattern is taken as the URL
- *   linkDest: the element where to place the Direct Download link
+ *   linkDestXPath: the XPath of the element where to place the Direct Download link
  *
  *
  * Optional fields:
@@ -78,27 +77,28 @@
 var supported_sites = [
   {
     locationRegexp: /^http:\/\/video\.repubblica\.it\/.*$/,
-    urlContainer: 'contA',
+    urlContainerXPath: '//div[@id="contA"]',
     urlRegexp: /'pcUrl', '((http|mms):\/\/[^']*)'/,
-    linkDest: 'contA',
+    linkDestXPath: '//div[@id="contA"]',
   },
   {
     locationRegexp: /^http:\/\/tv\.repubblica\.it\/.*$/,
-    urlContainer: 'boxPlayer',
+    urlContainerXPath: '//div[@id="boxPlayer"]',
     urlRegexp: /'pcUrl', '((http|mms):\/\/[^']*)'/,
     linkDest: 'box_embed',
+    linkDestXPath: '//div[@id="box_embed"]',
   },
   {
     locationRegexp: /^http:\/\/trovacinema\.repubblica\.it\/.*$/,
-    urlContainer: 'col-center',
+    urlContainerXPath: '//div[@id="col-center"]',
     urlRegexp: /'flvUrl', '((http|mms):\/\/[^']*)'/,
-    linkDest: 'col-center',
+    linkDestXPath: '//div[@id="col-center"]',
   },
   {
     locationRegexp: /^http:\/\/www\.kataweb\.it\/tvzap\/.*$/,
-    urlContainer: 'tvzap_video',
+    urlContainerXPath: '//div[@id="tvzap_video"]',
     urlRegexp: /'pcUrl', '((http|mms):\/\/[^']*)'/,
-    linkDest: 'playerCont',
+    linkDestXPath: '//div[@id="playerCont"]',
   },
   {
     locationRegexp: /^http:\/\/www\.rai\.tv\/.*$/,
@@ -107,17 +107,17 @@ var supported_sites = [
           return true;
         };
     },
-    urlContainer: 'Player',
+    urlContainerXPath: '//div[@id="Player"]',
     urlRegexp: /mediaUri=(http:\/\/[^,]*)/,
     onEvent: { evt: 'DOMNodeInserted', targetElement: 'object' },
     processURL: _rai_get_actual_url,
-    linkDest: 'Player',
+    linkDestXPath: '//div[@id="Player"]',
   },
   {
     locationRegexp: /^http:\/\/soundcloud.com\/.*$/,
-    urlContainer: 'main-content-inner',
+    urlContainerXPath: '//div[@id="main-content-inner"]',
     urlRegexp: /"streamUrl":"([^"]*)"/,
-    linkDest: 'main-content-inner',
+    linkDestXPath: '//div[@id="main-content-inner"]',
   },
 ];
 
@@ -134,6 +134,10 @@ for (i = 0; i < supported_sites.length; i++) {
   }
 }
 
+function getElementByXPath(query, root) {
+  return document.evaluate(query, root || document, null, XPathResult.ANY_UNORDERED_NODE_TYPE, null).singleNodeValue;
+}
+
 /**
  * Add a Direct Download link on the page for the specified URL
  *
@@ -142,9 +146,9 @@ for (i = 0; i < supported_sites.length; i++) {
  * @return: null on error, true on success
  */
 function direct_download_link_add(pageURL, site) {
-  var element = document.getElementById(site.urlContainer);
+  var element = getElementByXPath(site.urlContainerXPath);
   if (!element) {
-    DDL_log('DirectDL (' + site.pageURL  + '): Cannot find the element ' + site.urlContainer + ' containing the URL.');
+    DDL_log('DirectDL (' + site.pageURL  + '): Cannot find the element ' + site.urlContainerXPath + ' containing the URL.');
     return null;
   }
 
@@ -201,7 +205,7 @@ function _add_link(e) {
   var site = e.site;
   var URL = e.URL;;
 
-  var destination = document.getElementById(site.linkDest);
+  var destination = getElementByXPath(site.linkDestXPath);
   if (!destination) {
     DDL_log('DirectDl (' + site.pageURL + '): Cannot add the direct download link.');
     return;
-- 
2.1.4