Fix cloneNode/importNode for dom that contains templates.

src/Template/Template.js

@@ -85,25 +85,43 @@ if (typeof HTMLTemplateElement === 'undefined') {
         clone.content.appendChild(
             nativeCloneNode.call(template.content, true));
         // these two lists should be coincident
-        var s$ = template.content.querySelectorAll(TEMPLATE_TAG);
-        var t$ = clone.content.querySelectorAll(TEMPLATE_TAG);
-        for (var i=0, l=t$.length, t, s; i<l; i++) {
-          s = s$[i];
-          t = t$[i];
-          this.decorate(s);
-          t.parentNode.replaceChild(s.cloneNode(true), t);
-        }
+        this.fixClonedDom(clone.content, template.content);
       }
       return clone;
     };
 
+    HTMLTemplateElement.fixClonedDom = function(clone, source) {
+      var s$ = source.querySelectorAll(TEMPLATE_TAG);
+      var t$ = clone.querySelectorAll(TEMPLATE_TAG);
+      for (var i=0, l=t$.length, t, s; i<l; i++) {
+        s = s$[i];
+        t = t$[i];
+        this.decorate(s);
+        t.parentNode.replaceChild(s.cloneNode(true), t);
+      }
+    };
+
     var originalImportNode = document.importNode;
 
+    Node.prototype.cloneNode = function(deep) {
+      var dom = nativeCloneNode.call(this, deep);
+      if (deep) {
+        HTMLTemplateElement.fixClonedDom(dom, this);
+      }
+      return dom;
+    };
+
     // clone instead of importing <template>
     document.importNode = function(element, deep) {
-      return (element.localName === TEMPLATE_TAG) ?
-        HTMLTemplateElement.cloneNode(element, deep) :
-        originalImportNode.call(document, element, deep);
+      if (element.localName === TEMPLATE_TAG) {
+        return HTMLTemplateElement.cloneNode(element, deep);
+      } else {
+        var dom = originalImportNode.call(document, element, deep);
+        if (deep) {
+          HTMLTemplateElement.fixClonedDom(dom, element);
+        }
+        return dom;
+      }
     };
 
     /**

tests/Template/tests.html

@@ -80,7 +80,7 @@
               'cloned content is not different from source');
         });
 
-        test('nested clone', function() {
+        test('clone nested', function() {
           var imp = document.createElement('template');
           var s = 'a<template id="a">b<template id="b">c<template id="c">d</template></template></template>';
           imp.innerHTML = s;
@@ -108,6 +108,33 @@
               'deep cloned template.content is empty');
         });
 
+        test('clone node containing templates', function() {
+          var imp = document.createElement('div');
+          var t = document.createElement('template');
+          var s = 'a<template id="a">b<template id="b">c<template id="c">d</template></template></template>';
+          t.innerHTML = s;
+          imp.appendChild(t);
+          var impClone = imp.cloneNode(true);
+          var imp = imp.firstChild;
+          var deepClone = impClone.firstChild;
+          assert.equal(deepClone.content.childNodes.length, 2,
+              'deep cloned template.content is empty');
+          assert.notEqual(imp.content.firstChild, deepClone.content.firstChild,
+              'cloned content is not different from source');
+          var nested = deepClone.content.lastChild;
+          assert.isDefined(nested.content, 'nested cloned template content dne');
+          assert.equal(nested.content.childNodes.length, 2,
+              'deep cloned template.content is empty');
+          nested = nested.content.lastChild;
+          assert.isDefined(nested, 'nested cloned template content dne');
+          assert.equal(nested.content.childNodes.length, 2,
+              'deep cloned template.content is empty');
+          nested = nested.content.lastChild;
+          assert.isDefined(nested, 'nested cloned template content dne');
+          assert.equal(nested.content.childNodes.length, 1,
+              'deep cloned template.content is empty');
+        });
+
         test('importNode', function() {
           var imp = document.createElement('template');
           var s = '<div>Hi</div>';
@@ -124,7 +151,7 @@
               'cloned content is not different from source');
         });
 
-        test('nested importNode', function() {
+        test('importNode: nested', function() {
           var imp = document.createElement('template');
           var s = 'a<template id="a">b<template id="b">c<template id="c">d</template></template></template>';
           imp.innerHTML = s;
@@ -152,6 +179,33 @@
               'deep cloned template.content is empty');
         });
 
+        test('importNode: element containing nested templates', function() {
+          var imp = document.createElement('div');
+          var t = document.createElement('template');
+          var s = 'a<template id="a">b<template id="b">c<template id="c">d</template></template></template>';
+          t.innerHTML = s;
+          imp.appendChild(t);
+          var impClone = document.importNode(imp, true);
+          imp = imp.firstChild;
+          var deepClone = impClone.firstChild;
+          assert.equal(deepClone.content.childNodes.length, 2,
+              'deep cloned template.content is empty');
+          assert.notEqual(imp.content.firstChild, deepClone.content.firstChild,
+              'cloned content is not different from source');
+          var nested = deepClone.content.lastChild;
+          assert.isDefined(nested.content, 'nested cloned template content dne');
+          assert.equal(nested.content.childNodes.length, 2,
+              'deep cloned template.content is empty');
+          nested = nested.content.lastChild;
+          assert.isDefined(nested, 'nested cloned template content dne');
+          assert.equal(nested.content.childNodes.length, 2,
+              'deep cloned template.content is empty');
+          nested = nested.content.lastChild;
+          assert.isDefined(nested, 'nested cloned template content dne');
+          assert.equal(nested.content.childNodes.length, 1,
+              'deep cloned template.content is empty');
+        });
+
       });
     </script>
   </body>