by default, install template syntax once.

build.json

@@ -20,6 +20,7 @@
   "src/declaration/events.js",
   "src/declaration/properties.js",
   "src/declaration/attributes.js",
+  "src/declaration/mdv.js",
   "src/declaration/prototype.js",
   "src/declaration/queue.js",
   "src/declaration/import.js",

polymer.html

@@ -24,6 +24,7 @@
 <script src="src/declaration/events.js"></script>
 <script src="src/declaration/properties.js"></script>
 <script src="src/declaration/attributes.js"></script>
+<script src="src/declaration/mdv.js"></script>
 <script src="src/declaration/prototype.js"></script>
 <script src="src/declaration/queue.js"></script>
 <script src="src/declaration/import.js"></script>

src/declaration/mdv.js

@@ -0,0 +1,54 @@
+/*
+ * 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) {
+
+  // imports
+
+  var syntax = new PolymerExpressions();
+  syntax.resolveEventHandler = function(model, path, node) {
+    var ctlr = findEventController(node);
+    if (ctlr) {
+      var fn = path.getValueFrom(ctlr);
+      if (fn) {
+        return fn.bind(ctlr);
+      }
+    }
+  };
+
+  // An event controller is the host element for the shadowRoot in which 
+  // the node exists, or the first ancestor with a 'lightDomController'
+  // property.
+  function findEventController(node) {
+    while (node.parentNode) {
+      if (node.lightDomController) {
+        return node;
+      }
+      node = node.parentNode;
+    }
+    return node.host;
+  }
+
+  // declaration api supporting mdv
+  var mdv = {
+    syntax: syntax,
+    fetchTemplate: function() {
+      return this.querySelector('template');
+    },
+    templateContent: function() {
+      var template = this.fetchTemplate();
+      return template && templateContent(template);
+    },
+    installBindingDelegate: function(template) {
+      if (template) {
+        template.bindingDelegate = this.syntax;
+      }
+    }
+  };
+
+  // exports
+  scope.api.declaration.mdv = mdv;
+
+})(Polymer);

src/declaration/prototype.js

@@ -79,6 +79,8 @@
       // build side-chained lists to optimize iterations
       this.optimizePropertyMaps(this.prototype);
       this.createPropertyAccessors(this.prototype);
+      // install mdv delegate on template
+      this.installBindingDelegate(this.fetchTemplate());
       // install external stylesheets as if they are inline
       this.installSheets();
       // adjust any paths in dom from imports

src/declaration/styles.js

@@ -125,10 +125,6 @@
       }
       return matcher ? nodes.filter(matcher) : nodes;
     },
-    templateContent: function() {
-      var template = this.querySelector('template');
-      return template && templateContent(template);
-    },
     /**
      * Promotes external stylesheets and <style> elements with the attribute 
      * polymer-scope='global' into global scope.

src/instance/mdv.js

@@ -8,36 +8,10 @@
   // imports
 
   var log = window.logFlags || 0;
-  var events = scope.api.instance.events;
-
-  var syntax = new PolymerExpressions();
-  syntax.resolveEventHandler = function(model, path, node) {
-    var ctlr = findEventController(node);
-    if (ctlr) {
-      var fn = path.getValueFrom(ctlr);
-      if (fn) {
-        return fn.bind(ctlr);
-      }
-    }
-  }
-
-  // An event controller is the host element for the shadowRoot in which 
-  // the node exists, or the first ancestor with a 'lightDomController'
-  // property.
-  function findEventController(node) {
-    while (node.parentNode) {
-      if (node.lightDomController) {
-        return node;
-      }
-      node = node.parentNode;
-    }
-    return node.host;
-  };
 
   // element api supporting mdv
-
   var mdv = {
-    syntax: syntax,
+    //syntax: syntax,
     instanceTemplate: function(template) {
       var dom = template.createInstance(this, this.syntax);
       this.registerObservers(dom.bindings_);

src/polymer-body.html

@@ -62,6 +62,7 @@
         modelName: 'model',
 
         ready: function() {
+          this.syntax = this.element.syntax;
           this.template = document.querySelector('template');
           var model = window[this.modelName];
           if (model) {