From 3da8910da34fba3702bc78f083240cbb7c925369 Mon Sep 17 00:00:00 2001
From: Steve Orvell <steve@orvellia.com>
Date: Thu, 14 Nov 2013 18:30:46 -0800
Subject: [PATCH] =?UTF-8?q?Unresolved=20attribute=20available=20as=20a=20f?=
 =?UTF-8?q?eature=20of=20platform.=20With=20native=20imports,=20this=20sho?=
 =?UTF-8?q?uld=20be=20able=20to=20be=20removed.=20It=E2=80=99s=20needed=20?=
 =?UTF-8?q?because=20HTMLImports=20does=20not=20properly=20polyfill=20load?=
 =?UTF-8?q?ing=20imports=20before=20paint.?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 build.json        |  1 +
 platform.js       |  3 ++-
 src/unresolved.js | 59 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 62 insertions(+), 1 deletion(-)
 create mode 100644 src/unresolved.js

diff --git a/build.json b/build.json
index 41a2243..30c23c3 100644
--- a/build.json
+++ b/build.json
@@ -12,6 +12,7 @@
   "src/dom.js",
   "src/template.js",
   "src/inspector.js",
+  "src/unresolved.js",
   "../polymer-expressions/build.json",
   "src/patches-mdv.js",
   "../HTMLImports/build.json",
diff --git a/platform.js b/platform.js
index 4951ca9..bbf5c55 100644
--- a/platform.js
+++ b/platform.js
@@ -39,7 +39,8 @@ function processFlags(flags) {
       'src/lang.js',
       'src/dom.js',
       'src/template.js',
-      'src/inspector.js'
+      'src/inspector.js',
+      'src/unresolved.js'
     ];
 
     var MDV = [
diff --git a/src/unresolved.js b/src/unresolved.js
new file mode 100644
index 0000000..09ed320
--- /dev/null
+++ b/src/unresolved.js
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2013 The Polymer Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style
+ * license that can be found in the LICENSE file.
+ */
+(function(scope) {
+  /*
+    Shim :unresolved via an attribute unresolved.
+    TODO(sorvell): This is currently done once when the first
+    round of elements are upgraded. This is incorrect, and it will
+    need to be done dynamically.
+    The 'resolved' attribute is experimental and may be removed.
+  */
+  var TRANSITION_TIME = 0.2;
+  var UNRESOLVED = 'unresolved';
+  var RESOLVED = 'resolved';
+  var UNRESOLVED_SELECTOR = '[' + UNRESOLVED + ']';
+  var RESOLVED_SELECTOR = '[' + RESOLVED + ']';
+  var style = document.createElement('style');
+  
+  style.textContent = UNRESOLVED_SELECTOR + ' { ' +
+      'opacity: 0; display: block; overflow: hidden; } \n' +
+      RESOLVED_SELECTOR +  '{ display: block; overflow: hidden;\n' +
+      '-webkit-transition: opacity ' + TRANSITION_TIME + 's; ' +
+      'transition: opacity ' + TRANSITION_TIME +'s; }\n';
+  var head = document.querySelector('head');
+  head.insertBefore(style, head.firstChild);
+
+  // remove unresolved and apply resolved class
+  function resolveElements() {
+    requestAnimationFrame(function() {
+      var nodes = document.querySelectorAll(UNRESOLVED_SELECTOR);
+      for (var i=0, l=nodes.length, n; (i<l) && (n=nodes[i]); i++) {
+        n.removeAttribute(UNRESOLVED);
+        n.setAttribute(RESOLVED, '');
+      }
+
+      // NOTE: depends on transition end event to remove 'resolved' class.
+      if (nodes.length) {
+        var removeResolved = function() {
+          for (var i=0, l=nodes.length, n; (i<l) && (n=nodes[i]); i++) {
+            n.removeAttribute(RESOLVED);
+          }
+          document.body.removeEventListener(endEvent, removeResolved, false);
+        }
+        document.body.addEventListener(endEvent, removeResolved, false);
+      };
+
+    });
+  }
+
+  // determine transition end event
+  var endEvent = (document.documentElement.style.webkitTransition !== undefined) ?
+      'webkitTransitionEnd' : 'transitionend';
+
+  // hookup auto-unveiling
+  window.addEventListener('WebComponentsReady', resolveElements);
+
+})(Platform);