Rename mdv -> template_binding, remove experiemntal apis from dart:html

pkg/template_binding/lib/src/template.dart

+// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+part of template_binding;
+
+/** Extensions to [Element]s that behave as templates. */
+class TemplateBindExtension extends _ElementExtension {
+  var _model;
+  BindingDelegate _bindingDelegate;
+  _TemplateIterator _templateIterator;
+  bool _scheduled = false;
+
+  Element _templateInstanceRef;
+
+  // Note: only used if `this is! TemplateElement`
+  DocumentFragment _content;
+  bool _templateIsDecorated;
+
+  TemplateBindExtension._(Element node) : super(node);
+
+  Element get _node => super._node;
+
+  NodeBinding createBinding(String name, model, String path) {
+    switch (name) {
+      case 'bind':
+      case 'repeat':
+      case 'if':
+        if (_templateIterator == null) {
+          _templateIterator = new _TemplateIterator(_node);
+        }
+        // TODO(jmesserly): why do we do this here and nowhere else?
+        if (path == null) path = '';
+        return new _TemplateBinding(this, name, model, path);
+      default:
+        return super.createBinding(name, model, path);
+    }
+  }
+
+  /**
+   * Creates an instance of the template, using the provided model and optional
+   * binding delegate.
+   */
+  DocumentFragment createInstance([model, BindingDelegate delegate]) {
+    var instance = _createDeepCloneAndDecorateTemplates(
+        templateBind(ref).content, delegate);
+
+    _addBindings(instance, model, delegate);
+    _addTemplateInstanceRecord(instance, model);
+    return instance;
+  }
+
+  /** The data model which is inherited through the tree. */
+  get model => _model;
+
+  void set model(value) {
+    _model = value;
+    _ensureSetModelScheduled();
+  }
+
+  /**
+   * The binding delegate which is inherited through the tree. It can be used
+   * to configure custom syntax for `{{bindings}}` inside this template.
+   */
+  BindingDelegate get bindingDelegate => _bindingDelegate;
+
+  void set bindingDelegate(BindingDelegate value) {
+    _bindingDelegate = value;
+    _ensureSetModelScheduled();
+  }
+
+  _ensureSetModelScheduled() {
+    if (_scheduled) return;
+    _decorate();
+    _scheduled = true;
+    scheduleMicrotask(_setModel);
+  }
+
+  void _setModel() {
+    _scheduled = false;
+    _addBindings(_node, _model, _bindingDelegate);
+  }
+
+  /** Gets the template this node refers to. */
+  Element get ref {
+    _decorate();
+
+    Element result = null;
+    var refId = _node.attributes['ref'];
+    if (refId != null) {
+      var treeScope = _node;
+      while (treeScope.parentNode != null) {
+        treeScope = treeScope.parentNode;
+      }
+
+      // Note: JS code tests that getElementById is present. We can't do that
+      // easily, so instead check for the types known to implement it.
+      if (treeScope is Document ||
+          treeScope is ShadowRoot ||
+          treeScope is SvgSvgElement) {
+
+        result = treeScope.getElementById(refId);
+      }
+    }
+
+    if (result == null) {
+      result = _templateInstanceRef;
+      if (result == null) return _node;
+    }
+
+    var nextRef = templateBind(result).ref;
+    return nextRef != null ? nextRef : result;
+  }
+
+  /**
+   * Gets the content of this template.
+   */
+  DocumentFragment get content {
+    _decorate();
+    return _content != null ? _content : (_node as TemplateElement).content;
+  }
+
+  /**
+   * Ensures proper API and content model for template elements.
+   *
+   * [instanceRef] can be used to set the [Element.ref] property of [template],
+   * and use the ref's content will be used as source when createInstance() is
+   * invoked.
+   *
+   * Returns true if this template was just decorated, or false if it was
+   * already decorated.
+   */
+  static bool decorate(Element template, [Element instanceRef]) =>
+      templateBindFallback(template)._decorate(instanceRef);
+
+  bool _decorate([Element instanceRef]) {
+    // == true check because it starts as a null field.
+    if (_templateIsDecorated == true) return false;
+
+    _injectStylesheet();
+
+    var templateElementExt = this;
+    _templateIsDecorated = true;
+    var isNative = _node is TemplateElement;
+    var bootstrapContents = isNative;
+    var liftContents = !isNative;
+    var liftRoot = false;
+
+    if (!isNative && _isAttributeTemplate(_node)) {
+      if (instanceRef != null) {
+        // TODO(jmesserly): this is just an assert in MDV.
+        throw new ArgumentError('instanceRef should not be supplied for '
+            'attribute templates.');
+      }
+      templateElementExt = templateBind(
+          _extractTemplateFromAttributeTemplate(_node));
+      templateElementExt._templateIsDecorated = true;
+      isNative = templateElementExt._node is TemplateElement;
+      liftRoot = true;
+     }
+
+    if (!isNative) {
+      var doc = _getTemplateContentsOwner(
+          templateElementExt._node.ownerDocument);
+      templateElementExt._content = doc.createDocumentFragment();
+    }
+
+    if (instanceRef != null) {
+      // template is contained within an instance, its direct content must be
+      // empty
+      templateElementExt._templateInstanceRef = instanceRef;
+    } else if (liftContents) {
+      _liftNonNativeChildrenIntoContent(templateElementExt, _node, liftRoot);
+    } else if (bootstrapContents) {
+      bootstrap(templateElementExt.content);
+    }
+
+    return true;
+  }
+
+  static final _contentsOwner = new Expando();
+
+  // http://dvcs.w3.org/hg/webcomponents/raw-file/tip/spec/templates/index.html#dfn-template-contents-owner
+  static Document _getTemplateContentsOwner(HtmlDocument doc) {
+    if (doc.window == null) {
+      return doc;
+    }
+    var d = _contentsOwner[doc];
+    if (d == null) {
+      // TODO(arv): This should either be a Document or HTMLDocument depending
+      // on doc.
+      d = doc.implementation.createHtmlDocument('');
+      while (d.lastChild != null) {
+        d.lastChild.remove();
+      }
+      _contentsOwner[doc] = d;
+    }
+    return d;
+  }
+
+  // For non-template browsers, the parser will disallow <template> in certain
+  // locations, so we allow "attribute templates" which combine the template
+  // element with the top-level container node of the content, e.g.
+  //
+  //   <tr template repeat="{{ foo }}"" class="bar"><td>Bar</td></tr>
+  //
+  // becomes
+  //
+  //   <template repeat="{{ foo }}">
+  //   + #document-fragment
+  //     + <tr class="bar">
+  //       + <td>Bar</td>
+  //
+  static Element _extractTemplateFromAttributeTemplate(Element el) {
+    var template = el.ownerDocument.createElement('template');
+    el.parentNode.insertBefore(template, el);
+
+    for (var name in el.attributes.keys.toList()) {
+      switch (name) {
+        case 'template':
+          el.attributes.remove(name);
+          break;
+        case 'repeat':
+        case 'bind':
+        case 'ref':
+          template.attributes[name] = el.attributes.remove(name);
+          break;
+      }
+    }
+
+    return template;
+  }
+
+  static void _liftNonNativeChildrenIntoContent(TemplateBindExtension template,
+      Element el, bool useRoot) {
+
+    var content = template.content;
+    if (useRoot) {
+      content.append(el);
+      return;
+    }
+
+    var child;
+    while ((child = el.firstChild) != null) {
+      content.append(child);
+    }
+  }
+
+  /**
+   * This used to decorate recursively all templates from a given node.
+   *
+   * By default [decorate] will be called on templates lazily when certain
+   * properties such as [model] are accessed, but it can be run eagerly to
+   * decorate an entire tree recursively.
+   */
+  // TODO(rafaelw): Review whether this is the right public API.
+  static void bootstrap(Node content) {
+    void _bootstrap(template) {
+      if (!TemplateBindExtension.decorate(template)) {
+        bootstrap(templateBind(template).content);
+      }
+    }
+
+    // Need to do this first as the contents may get lifted if |node| is
+    // template.
+    // TODO(jmesserly): content is DocumentFragment or Element
+    var descendents =
+        (content as dynamic).querySelectorAll(_allTemplatesSelectors);
+    if (isSemanticTemplate(content)) {
+      _bootstrap(content);
+    }
+
+    descendents.forEach(_bootstrap);
+  }
+
+  static final String _allTemplatesSelectors =
+      'template, ' +
+      _SEMANTIC_TEMPLATE_TAGS.keys.map((k) => "$k[template]").join(", ");
+
+  static bool _initStyles;
+
+  static void _injectStylesheet() {
+    if (_initStyles == true) return;
+    _initStyles = true;
+
+    var style = new StyleElement();
+    style.text = r'''
+template,
+thead[template],
+tbody[template],
+tfoot[template],
+th[template],
+tr[template],
+td[template],
+caption[template],
+colgroup[template],
+col[template],
+option[template] {
+  display: none;
+}''';
+    document.head.append(style);
+  }
+}
+
+class _TemplateBinding extends NodeBinding {
+  TemplateBindExtension _ext;
+
+  // TODO(jmesserly): MDV uses TemplateIterator as the node, see:
+  // https://github.com/Polymer/mdv/issues/127
+  _TemplateBinding(ext, name, model, path)
+      : _ext = ext, super(ext._node, name, model, path) {
+    _ext._templateIterator.inputs.bind(property, model, path);
+  }
+
+  // These are no-ops because we don't use the underlying PathObserver.
+  void _observePath() {}
+  void boundValueChanged(newValue) {}
+
+  void close() {
+    if (closed) return;
+    var templateIterator = _ext._templateIterator;
+    if (templateIterator != null) templateIterator.inputs.unbind(property);
+    super.close();
+  }
+}