From 3977e66796a415234eb0278b077fafad82d63ed2 Mon Sep 17 00:00:00 2001
From: Andrew Dupont <prototype@andrewdupont.net>
Date: Fri, 12 Dec 2008 23:53:39 -0600
Subject: [PATCH] Added Element#store and Element#retrieve for safe,
 hash-backed storage of element metadata (no memory leaks). Also added
 Element#getStorage for working with the element's storage hash directly. Hat
 tip: Mootools.

---
 CHANGELOG             |  2 ++
 src/dom/dom.js        | 38 ++++++++++++++++++++++++++++++++++++++
 test/unit/dom_test.js | 17 +++++++++++++++++
 3 files changed, 57 insertions(+)

diff --git a/CHANGELOG b/CHANGELOG
index fa101e6..71f7cea 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -1,3 +1,5 @@
+* Added Element#store and Element#retrieve for safe, hash-backed storage of element metadata (no memory leaks). Also added Element#getStorage for working with the element's storage hash directly. Hat tip: Mootools. (ZenCocoon, Andrew Dupont)
+
 * Fix issue where certain versions of Safari treat class names case-insensitively in Selector/$$ queries. (Andrew Dupont, kangax, Brice)
 
 * Fix issue where Function#argumentNames returned incorrect results in IE when comments were intermixed with argument names. (Christophe Porteneuve, T.J. Crowder)
diff --git a/src/dom/dom.js b/src/dom/dom.js
index 0b59ca1..e90766f 100644
--- a/src/dom/dom.js
+++ b/src/dom/dom.js
@@ -1205,3 +1205,41 @@ document.viewport = {
       window.pageYOffset || document.documentElement.scrollTop || document.body.scrollTop);
   }
 };
+
+Element.Storage = {
+  UID: 1
+};
+
+Element.addMethods({
+  getStorage: function(element) {
+    if (!(element = $(element))) return;
+    
+    if (Object.isUndefined(element._prototypeUID))
+      element._prototypeUID = [Element.Storage.UID++];
+      
+    var uid = element._prototypeUID[0];
+    
+    if (!Element.Storage[uid])
+      Element.Storage[uid] = $H();
+    
+    return Element.Storage[uid];
+  },
+  
+  store: function(element, key, value) {
+    if (!(element = $(element))) return;
+    element.getStorage().set(key, value);
+  },
+  
+  retrieve: function(element, key, defaultValue) {
+    if (!(element = $(element))) return;
+    
+    var hash = element.getStorage(), value = hash.get(key);
+    
+    if (Object.isUndefined(value)) {
+      hash.set(key, defaultValue);
+      value = defaultValue;
+    }
+    
+    return value;
+  }
+});
diff --git a/test/unit/dom_test.js b/test/unit/dom_test.js
index 00d695c..4145e40 100644
--- a/test/unit/dom_test.js
+++ b/test/unit/dom_test.js
@@ -1365,6 +1365,23 @@ new Test.Unit.Runner({
     constants.each(function(pair) {
       this.assertEqual(Node[pair.key], pair.value);
     }, this);
+  },
+  
+  testElementStorage: function() {
+    var element = $('test-empty');
+    element.store('foo', 'bar');
+    this.assertEqual("bar", element.retrieve("foo"), "Setting and reading a property");
+    element.store('foo', 'thud');
+    this.assertEqual("thud", element.retrieve("foo"), "Re-setting and reading property");
+
+    element.store('bar', 'narf');
+    this.assertEnumEqual($w('foo bar'), element.getStorage().keys(), "Getting the storage hash");    
+    element.getStorage().unset('bar');
+    this.assertEnumEqual($w('foo'), element.getStorage().keys(), "Getting the storage hash after unsetting a key");
+    
+    
+    var clonedElement = $('test-empty').cloneNode(false);    
+    this.assert(!('_prototypeUID' in clonedElement), "Cloning a node should not confuse the storage engine");
   }
 });