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Unified Diff: packages/polymer/lib/src/instance.dart

Issue 2312183003: Removed Polymer from Observatory deps (Closed)
Patch Set: Created 4 years, 3 months ago
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Index: packages/polymer/lib/src/instance.dart
diff --git a/packages/polymer/lib/src/instance.dart b/packages/polymer/lib/src/instance.dart
deleted file mode 100644
index ca46d8db678934e17009c58c825e39abaa81594c..0000000000000000000000000000000000000000
--- a/packages/polymer/lib/src/instance.dart
+++ /dev/null
@@ -1,1466 +0,0 @@
-// 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 polymer;
-
-/// Use this annotation to publish a property as an attribute.
-///
-/// You can also use [PublishedProperty] to provide additional information,
-/// such as automatically syncing the property back to the attribute.
-///
-/// For example:
-///
-/// class MyPlaybackElement extends PolymerElement {
-/// // This will be available as an HTML attribute, for example:
-/// //
-/// // <my-playback volume="11">
-/// //
-/// // It will support initialization and data-binding via <template>:
-/// //
-/// // <template>
-/// // <my-playback volume="{{x}}">
-/// // </template>
-/// //
-/// // If the template is instantiated or given a model, `x` will be
-/// // used for this field and updated whenever `volume` changes.
-/// @published
-/// double get volume => readValue(#volume);
-/// set volume(double newValue) => writeValue(#volume, newValue);
-///
-/// // This will be available as an HTML attribute, like above, but it
-/// // will also serialize values set to the property to the attribute.
-/// // In other words, attributes['volume2'] will contain a serialized
-/// // version of this field.
-/// @PublishedProperty(reflect: true)
-/// double get volume2 => readValue(#volume2);
-/// set volume2(double newValue) => writeValue(#volume2, newValue);
-/// }
-///
-/// **Important note**: the pattern using `readValue` and `writeValue`
-/// guarantees that reading the property will give you the latest value at any
-/// given time, even if change notifications have not been propagated.
-///
-/// We still support using @published on a field, but this will not
-/// provide the same guarantees, so this is discouraged. For example:
-///
-/// // Avoid this if possible. This will be available as an HTML
-/// // attribute too, but you might need to delay reading volume3
-/// // asynchronously to guarantee that you read the latest value
-/// // set through bindings.
-/// @published double volume3;
-const published = const PublishedProperty();
-
-/// An annotation used to publish a field as an attribute. See [published].
-class PublishedProperty extends ObservableProperty {
- /// Whether the property value should be reflected back to the HTML attribute.
- final bool reflect;
-
- const PublishedProperty({this.reflect: false});
-}
-
-/// Use this type to observe a property and have the method be called when it
-/// changes. For example:
-///
-/// @ObserveProperty('foo.bar baz qux')
-/// validate() {
-/// // use this.foo.bar, this.baz, and this.qux in validation
-/// ...
-/// }
-///
-/// Note that you can observe a property path, and more than a single property
-/// can be specified in a space-delimited list or as a constant List.
-class ObserveProperty {
- final _names;
-
- List<String> get names {
- var n = _names;
- // TODO(jmesserly): the bogus '$n' is to workaround a dart2js bug, otherwise
- // it generates an incorrect call site.
- if (n is String) return '$n'.split(' ');
- if (n is! Iterable) {
- throw new UnsupportedError('ObserveProperty takes either an Iterable of '
- 'names, or a space separated String, instead of `$n`.');
- }
- return n;
- }
-
- const ObserveProperty(this._names);
-}
-
-/// Use this to create computed properties that are updated automatically. The
-/// annotation includes a polymer expression that describes how this property
-/// value can be expressed in terms of the values of other properties. For
-/// example:
-///
-/// class MyPlaybackElement extends PolymerElement {
-/// @observable int x;
-///
-/// // Reading xTimes2 will return x * 2.
-/// @ComputedProperty('x * 2')
-/// int get xTimes2 => readValue(#xTimes2);
-///
-/// If the polymer expression is assignable, you can also define a setter for
-/// it. For example:
-///
-/// // Reading c will return a.b, writing c will update a.b.
-/// @ComputedProperty('a.b')
-/// get c => readValue(#c);
-/// set c(newValue) => writeValue(#c, newValue);
-///
-/// The expression can do anything that is allowed in a polymer expresssion,
-/// even making calls to methods in your element. However, dependencies that are
-/// only used within those methods and that are not visible in the polymer
-/// expression, will not be observed. For example:
-///
-/// // Because `x` only appears inside method `m`, we will not notice
-/// // that `d` has changed if `x` is modified. However, `d` will be
-/// // updated whenever `c` changes.
-/// @ComputedProperty('m(c)')
-/// get d => readValue(#d);
-///
-/// m(c) => c + x;
-class ComputedProperty {
- /// A polymer expression, evaluated in the context of the custom element where
- /// this annotation is used.
- final String expression;
-
- const ComputedProperty(this.expression);
-}
-
-/// Base class for PolymerElements deriving from HtmlElement.
-///
-/// See [Polymer].
-class PolymerElement extends HtmlElement with Polymer, Observable {
- PolymerElement.created() : super.created() {
- polymerCreated();
- }
-}
-
-/// The mixin class for Polymer elements. It provides convenience features on
-/// top of the custom elements web standard.
-///
-/// If this class is used as a mixin,
-/// you must call `polymerCreated()` from the body of your constructor.
-abstract class Polymer implements Element, Observable, NodeBindExtension {
-
- // TODO(jmesserly): should this really be public?
- /// Regular expression that matches data-bindings.
- static final bindPattern = new RegExp(r'\{\{([^{}]*)}}');
-
- /// Like [document.register] but for Polymer elements.
- ///
- /// Use the [name] to specify custom elment's tag name, for example:
- /// "fancy-button" if the tag is used as `<fancy-button>`.
- ///
- /// The [type] is the type to construct. If not supplied, it defaults to
- /// [PolymerElement].
- // NOTE: this is called "element" in src/declaration/polymer-element.js, and
- // exported as "Polymer".
- static void register(String name, [Type type]) {
- //console.log('registering [' + name + ']');
- if (type == null) type = PolymerElement;
-
- _typesByName[name] = type;
-
- // Dart note: here we notify JS of the element registration. We don't pass
- // the Dart type because we will handle that in PolymerDeclaration.
- // See _hookJsPolymerDeclaration for how this is done.
- PolymerJs.constructor.apply([name]);
- (js.context['HTMLElement']['register'] as JsFunction)
- .apply([name, js.context['HTMLElement']['prototype']]);
- }
-
- /// Register a custom element that has no associated `<polymer-element>`.
- /// Unlike [register] this will always perform synchronous registration and
- /// by the time this method returns the element will be available using
- /// [document.createElement] or by modifying the HTML to include the element.
- static void registerSync(String name, Type type,
- {String extendsTag, Document doc, Node template}) {
-
- // Our normal registration, this will queue up the name->type association.
- register(name, type);
-
- // Build a polymer-element and initialize it to register
- if (doc == null) doc = document;
- var poly = doc.createElement('polymer-element');
- poly.attributes['name'] = name;
- if (extendsTag != null) poly.attributes['extends'] = extendsTag;
- if (template != null) poly.append(template);
-
- // TODO(jmesserly): conceptually this is just:
- // new JsObject.fromBrowserObject(poly).callMethod('init')
- //
- // However doing it that way hits an issue with JS-interop in IE10: we get a
- // JsObject that wraps something other than `poly`, due to improper caching.
- // By reusing _polymerElementProto that we used for 'register', we can
- // then call apply on it to invoke init() with the correct `this` pointer.
- JsFunction init = _polymerElementProto['init'];
- init.apply([], thisArg: poly);
- }
-
- // Warning for when people try to use `importElements` or `import`.
- static const String _DYNAMIC_IMPORT_WARNING = 'Dynamically loading html '
- 'imports has very limited support right now in dart, see '
- 'http://dartbug.com/17873.';
-
- /// Loads the set of HTMLImports contained in `node`. Returns a future that
- /// resolves when all the imports have been loaded. This method can be used to
- /// lazily load imports. For example, given a template:
- ///
- /// <template>
- /// <link rel="import" href="my-import1.html">
- /// <link rel="import" href="my-import2.html">
- /// </template>
- ///
- /// Polymer.importElements(template.content)
- /// .then((_) => print('imports lazily loaded'));
- ///
- /// Dart Note: This has very limited support in dart, http://dartbug.com/17873
- // Dart Note: From src/lib/import.js For now proxy to the JS methods,
- // because we want to share the loader with polymer.js for interop purposes.
- static Future importElements(Node elementOrFragment) {
- print(_DYNAMIC_IMPORT_WARNING);
- return PolymerJs.importElements(elementOrFragment);
- }
-
- /// Loads an HTMLImport for each url specified in the `urls` array. Notifies
- /// when all the imports have loaded by calling the `callback` function
- /// argument. This method can be used to lazily load imports. For example,
- /// For example,
- ///
- /// Polymer.import(['my-import1.html', 'my-import2.html'])
- /// .then((_) => print('imports lazily loaded'));
- ///
- /// Dart Note: This has very limited support in dart, http://dartbug.com/17873
- // Dart Note: From src/lib/import.js. For now proxy to the JS methods,
- // because we want to share the loader with polymer.js for interop purposes.
- static Future import(List urls) {
- print(_DYNAMIC_IMPORT_WARNING);
- return PolymerJs.import(urls);
- }
-
- /// Deprecated: Use `import` instead.
- @deprecated
- static Future importUrls(List urls) {
- return import(urls);
- }
-
- /// Completes when polymer js is ready.
- static final Completer _onReady = new Completer();
-
- /// Completes when all initialization is done.
- static final Completer _onInitDone = new Completer();
-
- /// Future indicating that the Polymer library has been loaded and is ready
- /// for use.
- static Future get onReady =>
- Future.wait([_onReady.future, _onInitDone.future]);
-
- /// Returns a list of elements that have had polymer-elements created but
- /// are not yet ready to register. The list is an array of element
- /// definitions.
- static List<Element> get waitingFor => PolymerJs.waitingFor;
-
- /// Forces polymer to register any pending elements. Can be used to abort
- /// waiting for elements that are partially defined.
- static forceReady([int timeout]) => PolymerJs.forceReady(timeout);
-
- /// The most derived `<polymer-element>` declaration for this element.
- PolymerDeclaration get element => _element;
- PolymerDeclaration _element;
-
- /// Deprecated: use [element] instead.
- @deprecated PolymerDeclaration get declaration => _element;
-
- Map<String, StreamSubscription> _namedObservers;
- List<Bindable> _observers = [];
-
- bool _unbound; // lazy-initialized
- PolymerJob _unbindAllJob;
-
- CompoundObserver _propertyObserver;
- bool _readied = false;
-
- JsObject _jsElem;
-
- /// Returns the object that should be used as the event controller for
- /// event bindings in this element's template. If set, this will override the
- /// normal controller lookup.
- // TODO(jmesserly): we need to use a JS-writable property as our backing
- // store, because of elements such as:
- // https://github.com/Polymer/core-overlay/blob/eeb14853/core-overlay-layer.html#L78
- get eventController => _jsElem['eventController'];
- set eventController(value) {
- _jsElem['eventController'] = value;
- }
-
- bool get hasBeenAttached => _hasBeenAttached;
- bool _hasBeenAttached = false;
-
- /// Gets the shadow root associated with the corresponding custom element.
- ///
- /// This is identical to [shadowRoot], unless there are multiple levels of
- /// inheritance and they each have their own shadow root. For example,
- /// this can happen if the base class and subclass both have `<template>` tags
- /// in their `<polymer-element>` tags.
- // TODO(jmesserly): should expose this as an immutable map.
- // Similar issue as $.
- final Map<String, ShadowRoot> shadowRoots =
- new LinkedHashMap<String, ShadowRoot>();
-
- /// Map of items in the shadow root(s) by their [Element.id].
- // TODO(jmesserly): various issues:
- // * wrap in UnmodifiableMapView?
- // * should we have an object that implements noSuchMethod?
- // * should the map have a key order (e.g. LinkedHash or SplayTree)?
- // * should this be a live list? Polymer doesn't, maybe due to JS limitations?
- // Note: this is observable to support $['someId'] being used in templates.
- // The template is stamped before $ is populated, so we need observation if
- // we want it to be usable in bindings.
- final Map<String, dynamic> $ = new ObservableMap<String, dynamic>();
-
- /// Use to override the default syntax for polymer-elements.
- /// By default this will be null, which causes [instanceTemplate] to use
- /// the template's bindingDelegate or the [element.syntax], in that order.
- PolymerExpressions get syntax => null;
-
- bool get _elementPrepared => _element != null;
-
- /// Retrieves the custom element name. It should be used instead
- /// of localName, see: https://github.com/Polymer/polymer-dev/issues/26
- String get _name {
- if (_element != null) return _element.name;
- var isAttr = attributes['is'];
- return (isAttr == null || isAttr == '') ? localName : isAttr;
- }
-
- /// By default the data bindings will be cleaned up when this custom element
- /// is detached from the document. Overriding this to return `true` will
- /// prevent that from happening.
- bool get preventDispose => false;
-
- /// Properties exposed by this element.
- // Dart note: unlike Javascript we can't override the original property on
- // the object, so we use this mechanism instead to define properties. See more
- // details in [_PropertyAccessor].
- Map<Symbol, _PropertyAccessor> _properties = {};
-
- /// Helper to implement a property with the given [name]. This is used for
- /// normal and computed properties. Normal properties can provide the initial
- /// value using the [initialValue] function. Computed properties ignore
- /// [initialValue], their value is derived from the expression in the
- /// [ComputedProperty] annotation that appears above the getter that uses this
- /// helper.
- readValue(Symbol name, [initialValue()]) {
- var property = _properties[name];
- if (property == null) {
- var value;
- // Dart note: most computed properties are created in advance in
- // createComputedProperties, but if one computed property depends on
- // another, the declaration order might matter. Rather than trying to
- // register them in order, we include here also the option of lazily
- // creating the property accessor on the first read.
- var binding = _getBindingForComputedProperty(name);
- if (binding == null) {
- // normal property
- value = initialValue != null ? initialValue() : null;
- } else {
- value = binding.value;
- }
- property = _properties[name] = new _PropertyAccessor(name, this, value);
- }
- return property.value;
- }
-
- /// Helper to implement a setter of a property with the given [name] on a
- /// polymer element. This can be used on normal properties and also on
- /// computed properties, as long as the expression used for the computed
- /// property is assignable (see [ComputedProperty]).
- writeValue(Symbol name, newValue) {
- var property = _properties[name];
- if (property == null) {
- // Note: computed properties are created in advance in
- // createComputedProperties, so we should only need to create here
- // non-computed properties.
- property = _properties[name] = new _PropertyAccessor(name, this, null);
- }
- property.value = newValue;
- }
-
- /// If this class is used as a mixin, this method must be called from inside
- /// of the `created()` constructor.
- ///
- /// If this class is a superclass, calling `super.created()` is sufficient.
- void polymerCreated() {
- var t = nodeBind(this).templateInstance;
- if (t != null && t.model != null) {
- window.console.warn('Attributes on $_name were data bound '
- 'prior to Polymer upgrading the element. This may result in '
- 'incorrect binding types.');
- }
- prepareElement();
- if (!isTemplateStagingDocument(ownerDocument)) {
- _makeElementReady();
- }
- }
-
- /// *Deprecated* use [shadowRoots] instead.
- @deprecated
- ShadowRoot getShadowRoot(String customTagName) => shadowRoots[customTagName];
-
- void prepareElement() {
- if (_elementPrepared) {
- window.console.warn('Element already prepared: $_name');
- return;
- }
- _initJsObject();
- // Dart note: get the corresponding <polymer-element> declaration.
- _element = _getDeclaration(_name);
- // install property storage
- createPropertyObserver();
- openPropertyObserver();
- // install boilerplate attributes
- copyInstanceAttributes();
- // process input attributes
- takeAttributes();
- // add event listeners
- addHostListeners();
- }
-
- /// Initialize JS interop for this element. For now we just initialize the
- /// JsObject, but in the future we could also initialize JS APIs here.
- _initJsObject() {
- _jsElem = new JsObject.fromBrowserObject(this);
- }
-
- /// Deprecated: This is no longer a public method.
- @deprecated
- makeElementReady() => _makeElementReady();
-
- _makeElementReady() {
- if (_readied) return;
- _readied = true;
- createComputedProperties();
-
- parseDeclarations(_element);
- // NOTE: Support use of the `unresolved` attribute to help polyfill
- // custom elements' `:unresolved` feature.
- attributes.remove('unresolved');
- // user entry point
- _readyLog.info(() => '[$this]: ready');
- ready();
- }
-
- /// Lifecycle method called when the element has populated it's `shadowRoot`,
- /// prepared data-observation, and made itself ready for API interaction.
- /// To wait until the element has been attached to the default view, use
- /// [attached] or [domReady].
- void ready() {}
-
- /// Implement to access custom elements in dom descendants, ancestors,
- /// or siblings. Because custom elements upgrade in document order,
- /// elements accessed in `ready` or `attached` may not be upgraded. When
- /// `domReady` is called, all registered custom elements are guaranteed
- /// to have been upgraded.
- void domReady() {}
-
- void attached() {
- if (!_elementPrepared) {
- // Dart specific message for a common issue.
- throw new StateError('polymerCreated was not called for custom element '
- '$_name, this should normally be done in the .created() if Polymer '
- 'is used as a mixin.');
- }
-
- cancelUnbindAll();
- if (!hasBeenAttached) {
- _hasBeenAttached = true;
- async((_) => domReady());
- }
- }
-
- void detached() {
- if (!preventDispose) asyncUnbindAll();
- }
-
- /// Walks the prototype-chain of this element and allows specific
- /// classes a chance to process static declarations.
- ///
- /// In particular, each polymer-element has it's own `template`.
- /// `parseDeclarations` is used to accumulate all element `template`s
- /// from an inheritance chain.
- ///
- /// `parseDeclaration` static methods implemented in the chain are called
- /// recursively, oldest first, with the `<polymer-element>` associated
- /// with the current prototype passed as an argument.
- ///
- /// An element may override this method to customize shadow-root generation.
- void parseDeclarations(PolymerDeclaration declaration) {
- if (declaration != null) {
- parseDeclarations(declaration.superDeclaration);
- parseDeclaration(declaration.element);
- }
- }
-
- /// Perform init-time actions based on static information in the
- /// `<polymer-element>` instance argument.
- ///
- /// For example, the standard implementation locates the template associated
- /// with the given `<polymer-element>` and stamps it into a shadow-root to
- /// implement shadow inheritance.
- ///
- /// An element may override this method for custom behavior.
- void parseDeclaration(Element elementElement) {
- var template = fetchTemplate(elementElement);
-
- if (template != null) {
- var root = shadowFromTemplate(template);
-
- var name = elementElement.attributes['name'];
- if (name == null) return;
- shadowRoots[name] = root;
- }
- }
-
- /// Given a `<polymer-element>`, find an associated template (if any) to be
- /// used for shadow-root generation.
- ///
- /// An element may override this method for custom behavior.
- Element fetchTemplate(Element elementElement) =>
- elementElement.querySelector('template');
-
- /// Utility function that stamps a `<template>` into light-dom.
- Node lightFromTemplate(Element template, [Node refNode]) {
- if (template == null) return null;
-
- // TODO(sorvell): mark this element as an event controller so that
- // event listeners on bound nodes inside it will be called on it.
- // Note, the expectation here is that events on all descendants
- // should be handled by this element.
- eventController = this;
-
- // stamp template
- // which includes parsing and applying MDV bindings before being
- // inserted (to avoid {{}} in attribute values)
- // e.g. to prevent <img src="images/{{icon}}"> from generating a 404.
- var dom = instanceTemplate(template);
- // append to shadow dom
- if (refNode != null) {
- append(dom);
- } else {
- insertBefore(dom, refNode);
- }
- // perform post-construction initialization tasks on ahem, light root
- shadowRootReady(this);
- // return the created shadow root
- return dom;
- }
-
- /// Utility function that creates a shadow root from a `<template>`.
- ///
- /// The base implementation will return a [ShadowRoot], but you can replace it
- /// with your own code and skip ShadowRoot creation. In that case, you should
- /// return `null`.
- ///
- /// In your overridden method, you can use [instanceTemplate] to stamp the
- /// template and initialize data binding, and [shadowRootReady] to intialize
- /// other Polymer features like event handlers. It is fine to call
- /// shadowRootReady with a node other than a ShadowRoot such as with `this`.
- ShadowRoot shadowFromTemplate(Element template) {
- if (template == null) return null;
- // make a shadow root
- var root = createShadowRoot();
- // stamp template
- // which includes parsing and applying MDV bindings before being
- // inserted (to avoid {{}} in attribute values)
- // e.g. to prevent <img src="images/{{icon}}"> from generating a 404.
- var dom = instanceTemplate(template);
- // append to shadow dom
- root.append(dom);
- // perform post-construction initialization tasks on shadow root
- shadowRootReady(root);
- // return the created shadow root
- return root;
- }
-
- void shadowRootReady(Node root) {
- // locate nodes with id and store references to them in this.$ hash
- marshalNodeReferences(root);
- }
-
- /// Locate nodes with id and store references to them in [$] hash.
- void marshalNodeReferences(Node root) {
- if (root == null) return;
- for (var n in (root as dynamic).querySelectorAll('[id]')) {
- $[n.id] = n;
- }
- }
-
- void attributeChanged(String name, String oldValue, String newValue) {
- if (name != 'class' && name != 'style') {
- attributeToProperty(name, newValue);
- }
- }
-
- // TODO(jmesserly): this could be a top level method.
- /// Returns a future when `node` changes, or when its children or subtree
- /// changes.
- ///
- /// Use [MutationObserver] if you want to listen to a stream of changes.
- Future<List<MutationRecord>> onMutation(Node node) {
- var completer = new Completer();
- new MutationObserver((mutations, observer) {
- observer.disconnect();
- completer.complete(mutations);
- })..observe(node, childList: true, subtree: true);
- return completer.future;
- }
-
- // copy attributes defined in the element declaration to the instance
- // e.g. <polymer-element name="x-foo" tabIndex="0"> tabIndex is copied
- // to the element instance here.
- void copyInstanceAttributes() {
- _element._instanceAttributes.forEach((name, value) {
- attributes.putIfAbsent(name, () => value);
- });
- }
-
- void takeAttributes() {
- if (_element._publishLC == null) return;
- attributes.forEach(attributeToProperty);
- }
-
- /// If attribute [name] is mapped to a property, deserialize
- /// [value] into that property.
- void attributeToProperty(String name, String value) {
- // try to match this attribute to a property (attributes are
- // all lower-case, so this is case-insensitive search)
- var decl = propertyForAttribute(name);
- if (decl == null) return;
-
- // filter out 'mustached' values, these are to be
- // replaced with bound-data and are not yet values
- // themselves.
- if (value == null || value.contains(Polymer.bindPattern)) return;
-
- final currentValue = smoke.read(this, decl.name);
-
- // deserialize Boolean or Number values from attribute
- var type = decl.type;
- if ((type == Object || type == dynamic) && currentValue != null) {
- // Attempt to infer field type from the current value.
- type = currentValue.runtimeType;
- }
- final newValue = deserializeValue(value, currentValue, type);
-
- // only act if the value has changed
- if (!identical(newValue, currentValue)) {
- // install new value (has side-effects)
- smoke.write(this, decl.name, newValue);
- }
- }
-
- /// Return the published property matching name, or null.
- // TODO(jmesserly): should we just return Symbol here?
- smoke.Declaration propertyForAttribute(String name) {
- final publishLC = _element._publishLC;
- if (publishLC == null) return null;
- return publishLC[name];
- }
-
- /// Convert representation of [value] based on [type] and [currentValue].
- Object deserializeValue(String value, Object currentValue, Type type) =>
- deserialize.deserializeValue(value, currentValue, type);
-
- String serializeValue(Object value) {
- if (value == null) return null;
-
- if (value is bool) {
- return _toBoolean(value) ? '' : null;
- } else if (value is String || value is num) {
- return '$value';
- }
- return null;
- }
-
- void reflectPropertyToAttribute(String path) {
- // TODO(sjmiles): consider memoizing this
- // try to intelligently serialize property value
- final propValue = new PropertyPath(path).getValueFrom(this);
- final serializedValue = serializeValue(propValue);
- // boolean properties must reflect as boolean attributes
- if (serializedValue != null) {
- attributes[path] = serializedValue;
- // TODO(sorvell): we should remove attr for all properties
- // that have undefined serialization; however, we will need to
- // refine the attr reflection system to achieve this; pica, for example,
- // relies on having inferredType object properties not removed as
- // attrs.
- } else if (propValue is bool) {
- attributes.remove(path);
- }
- }
-
- /// Creates the document fragment to use for each instance of the custom
- /// element, given the `<template>` node. By default this is equivalent to:
- ///
- /// templateBind(template).createInstance(this, polymerSyntax);
- ///
- /// Where polymerSyntax is a singleton [PolymerExpressions] instance.
- ///
- /// You can override this method to change the instantiation behavior of the
- /// template, for example to use a different data-binding syntax.
- DocumentFragment instanceTemplate(Element template) {
- // ensure template is decorated (lets things like <tr template ...> work)
- TemplateBindExtension.decorate(template);
- var syntax = this.syntax;
- var t = templateBind(template);
- if (syntax == null && t.bindingDelegate == null) {
- syntax = element.syntax;
- }
- var dom = t.createInstance(this, syntax);
- _observers.addAll(getTemplateInstanceBindings(dom));
- return dom;
- }
-
- /// Called by TemplateBinding/NodeBind to setup a binding to the given
- /// property. It's overridden here to support property bindings in addition to
- /// attribute bindings that are supported by default.
- Bindable bind(String name, bindable, {bool oneTime: false}) {
- var decl = propertyForAttribute(name);
- if (decl == null) {
- // Cannot call super.bind because template_binding is its own package
- return nodeBindFallback(this).bind(name, bindable, oneTime: oneTime);
- } else {
- // use n-way Polymer binding
- var observer = bindProperty(decl.name, bindable, oneTime: oneTime);
- // NOTE: reflecting binding information is typically required only for
- // tooling. It has a performance cost so it's opt-in in Node.bind.
- if (enableBindingsReflection && observer != null) {
- // Dart note: this is not needed because of how _PolymerBinding works.
- //observer.path = bindable.path_;
- _recordBinding(name, observer);
- }
- var reflect = _element._reflect;
-
- // Get back to the (possibly camel-case) name for the property.
- var propName = smoke.symbolToName(decl.name);
- if (reflect != null && reflect.contains(propName)) {
- reflectPropertyToAttribute(propName);
- }
- return observer;
- }
- }
-
- _recordBinding(String name, observer) {
- if (bindings == null) bindings = {};
- this.bindings[name] = observer;
- }
-
- /// Called by TemplateBinding when all bindings on an element have been
- /// executed. This signals that all element inputs have been gathered and it's
- /// safe to ready the element, create shadow-root and start data-observation.
- bindFinished() => _makeElementReady();
-
- Map<String, Bindable> get bindings => nodeBindFallback(this).bindings;
- set bindings(Map value) {
- nodeBindFallback(this).bindings = value;
- }
-
- TemplateInstance get templateInstance =>
- nodeBindFallback(this).templateInstance;
-
- /// Called at detached time to signal that an element's bindings should be
- /// cleaned up. This is done asynchronously so that users have the chance to
- /// call `cancelUnbindAll` to prevent unbinding.
- void asyncUnbindAll() {
- if (_unbound == true) return;
- _unbindLog.fine(() => '[$_name] asyncUnbindAll');
- _unbindAllJob = scheduleJob(_unbindAllJob, unbindAll);
- }
-
- /// This method should rarely be used and only if `cancelUnbindAll` has been
- /// called to prevent element unbinding. In this case, the element's bindings
- /// will not be automatically cleaned up and it cannot be garbage collected by
- /// by the system. If memory pressure is a concern or a large amount of
- /// elements need to be managed in this way, `unbindAll` can be called to
- /// deactivate the element's bindings and allow its memory to be reclaimed.
- void unbindAll() {
- if (_unbound == true) return;
- closeObservers();
- closeNamedObservers();
- _unbound = true;
- }
-
- //// Call in `detached` to prevent the element from unbinding when it is
- //// detached from the dom. The element is unbound as a cleanup step that
- //// allows its memory to be reclaimed. If `cancelUnbindAll` is used, consider
- /// calling `unbindAll` when the element is no longer needed. This will allow
- /// its memory to be reclaimed.
- void cancelUnbindAll() {
- if (_unbound == true) {
- _unbindLog
- .warning(() => '[$_name] already unbound, cannot cancel unbindAll');
- return;
- }
- _unbindLog.fine(() => '[$_name] cancelUnbindAll');
- if (_unbindAllJob != null) {
- _unbindAllJob.stop();
- _unbindAllJob = null;
- }
- }
-
- static void _forNodeTree(Node node, void callback(Node node)) {
- if (node == null) return;
-
- callback(node);
- for (var child = node.firstChild; child != null; child = child.nextNode) {
- _forNodeTree(child, callback);
- }
- }
-
- /// Creates a CompoundObserver to observe property changes.
- /// NOTE, this is only done if there are any properties in the `_observe`
- /// object.
- void createPropertyObserver() {
- final observe = _element._observe;
- if (observe != null) {
- var o = _propertyObserver = new CompoundObserver();
- // keep track of property observer so we can shut it down
- _observers.add(o);
-
- for (var path in observe.keys) {
- o.addPath(this, path);
-
- // TODO(jmesserly): on the Polymer side it doesn't look like they
- // will observe arrays unless it is a length == 1 path.
- observeArrayValue(path, path.getValueFrom(this), null);
- }
- }
- }
-
- /// Start observing property changes.
- void openPropertyObserver() {
- if (_propertyObserver != null) {
- _propertyObserver.open(notifyPropertyChanges);
- }
-
- // Dart note: we need an extra listener only to continue supporting
- // @published properties that follow the old syntax until we get rid of it.
- // This workaround has timing issues so we prefer the new, not so nice,
- // syntax.
- if (_element._publish != null) {
- changes.listen(_propertyChangeWorkaround);
- }
- }
-
- /// Handler for property changes; routes changes to observing methods.
- /// Note: array valued properties are observed for array splices.
- void notifyPropertyChanges(List newValues, Map oldValues, List paths) {
- final observe = _element._observe;
- final called = new HashSet();
-
- oldValues.forEach((i, oldValue) {
- final newValue = newValues[i];
-
- // Date note: we don't need any special checking for null and undefined.
-
- // note: paths is of form [object, path, object, path]
- final path = paths[2 * i + 1];
- if (observe == null) return;
-
- var methods = observe[path];
- if (methods == null) return;
-
- for (var method in methods) {
- if (!called.add(method)) continue; // don't invoke more than once.
-
- observeArrayValue(path, newValue, oldValue);
- // Dart note: JS passes "arguments", so we pass along our args.
- // TODO(sorvell): call method with the set of values it's expecting;
- // e.g. 'foo bar': 'invalidate' expects the new and old values for
- // foo and bar. Currently we give only one of these and then
- // deliver all the arguments.
- smoke.invoke(
- this, method, [oldValue, newValue, newValues, oldValues, paths],
- adjust: true);
- }
- });
- }
-
- /// Force any pending property changes to synchronously deliver to handlers
- /// specified in the `observe` object.
- /// Note: normally changes are processed at microtask time.
- ///
- // Dart note: had to rename this to avoid colliding with
- // Observable.deliverChanges. Even worse, super calls aren't possible or
- // it prevents Polymer from being a mixin, so we can't override it even if
- // we wanted to.
- void deliverPropertyChanges() {
- if (_propertyObserver != null) {
- _propertyObserver.deliver();
- }
- }
-
- // Dart note: this workaround is only for old-style @published properties,
- // which have timing issues. See _bindOldStylePublishedProperty below.
- // TODO(sigmund): deprecate this.
- void _propertyChangeWorkaround(List<ChangeRecord> records) {
- for (var record in records) {
- if (record is! PropertyChangeRecord) continue;
-
- var name = record.name;
- // The setter of a new-style property will create an accessor in
- // _properties[name]. We can skip the workaround for those properties.
- if (_properties[name] != null) continue;
- _propertyChange(name, record.newValue, record.oldValue);
- }
- }
-
- void _propertyChange(Symbol nameSymbol, newValue, oldValue) {
- _watchLog.info(
- () => '[$this]: $nameSymbol changed from: $oldValue to: $newValue');
- var name = smoke.symbolToName(nameSymbol);
- var reflect = _element._reflect;
- if (reflect != null && reflect.contains(name)) {
- reflectPropertyToAttribute(name);
- }
- }
-
- void observeArrayValue(PropertyPath name, Object value, Object old) {
- final observe = _element._observe;
- if (observe == null) return;
-
- // we only care if there are registered side-effects
- var callbacks = observe[name];
- if (callbacks == null) return;
-
- // if we are observing the previous value, stop
- if (old is ObservableList) {
- _observeLog.fine(() => '[$_name] observeArrayValue: unregister $name');
-
- closeNamedObserver('${name}__array');
- }
- // if the new value is an array, begin observing it
- if (value is ObservableList) {
- _observeLog.fine(() => '[$_name] observeArrayValue: register $name');
- var sub = value.listChanges.listen((changes) {
- for (var callback in callbacks) {
- smoke.invoke(this, callback, [changes], adjust: true);
- }
- });
- registerNamedObserver('${name}__array', sub);
- }
- }
-
- emitPropertyChangeRecord(Symbol name, newValue, oldValue) {
- if (identical(oldValue, newValue)) return;
- _propertyChange(name, newValue, oldValue);
- }
-
- bindToAccessor(Symbol name, Bindable bindable, {resolveBindingValue: false}) {
- // Dart note: our pattern is to declare the initial value in the getter. We
- // read it via smoke to ensure that the value is initialized correctly.
- var oldValue = smoke.read(this, name);
- var property = _properties[name];
- if (property == null) {
- // We know that _properties[name] is null only for old-style @published
- // properties. This fallback is here to make it easier to deprecate the
- // old-style of published properties, which have bad timing guarantees
- // (see comment in _PolymerBinding).
- return _bindOldStylePublishedProperty(name, bindable, oldValue);
- }
-
- property.bindable = bindable;
- var value = bindable.open(property.updateValue);
-
- if (resolveBindingValue) {
- // capture A's value if B's value is null or undefined,
- // otherwise use B's value
- var v = (value == null ? oldValue : value);
- if (!identical(value, oldValue)) {
- bindable.value = value = v;
- }
- }
-
- property.updateValue(value);
- var o = new _CloseOnlyBinding(property);
- _observers.add(o);
- return o;
- }
-
- // Dart note: this fallback uses our old-style binding mechanism to be able to
- // link @published properties with bindings. This mechanism is backwards from
- // what Javascript does because we can't override the original property. This
- // workaround also brings some timing issues which are described in detail in
- // dartbug.com/18343.
- // TODO(sigmund): deprecate old-style @published properties.
- _bindOldStylePublishedProperty(Symbol name, Bindable bindable, oldValue) {
- // capture A's value if B's value is null or undefined,
- // otherwise use B's value
- if (bindable.value == null) bindable.value = oldValue;
-
- var o = new _PolymerBinding(this, name, bindable);
- _observers.add(o);
- return o;
- }
-
- _getBindingForComputedProperty(Symbol name) {
- var exprString = element._computed[name];
- if (exprString == null) return null;
- var expr = PolymerExpressions.getExpression(exprString);
- return PolymerExpressions.getBinding(expr, this,
- globals: element.syntax.globals);
- }
-
- createComputedProperties() {
- var computed = this.element._computed;
- for (var name in computed.keys) {
- try {
- // Dart note: this is done in Javascript by modifying the prototype in
- // declaration/properties.js, we can't do that, so we do it here.
- var binding = _getBindingForComputedProperty(name);
-
- // Follow up note: ideally we would only create the accessor object
- // here, but some computed properties might depend on others and
- // evaluating `binding.value` could try to read the value of another
- // computed property that we haven't created yet. For this reason we
- // also allow to also create the accessor in [readValue].
- if (_properties[name] == null) {
- _properties[name] = new _PropertyAccessor(name, this, binding.value);
- }
- bindToAccessor(name, binding);
- } catch (e) {
- window.console.error('Failed to create computed property $name'
- ' (${computed[name]}): $e');
- }
- }
- }
-
- // Dart note: to simplify the code above we made registerObserver calls
- // directly invoke _observers.add/addAll.
- void closeObservers() {
- for (var o in _observers) {
- if (o != null) o.close();
- }
- _observers = [];
- }
-
- /// Bookkeeping observers for memory management.
- void registerNamedObserver(String name, StreamSubscription sub) {
- if (_namedObservers == null) {
- _namedObservers = new Map<String, StreamSubscription>();
- }
- _namedObservers[name] = sub;
- }
-
- bool closeNamedObserver(String name) {
- var sub = _namedObservers.remove(name);
- if (sub == null) return false;
- sub.cancel();
- return true;
- }
-
- void closeNamedObservers() {
- if (_namedObservers == null) return;
- for (var sub in _namedObservers.values) {
- if (sub != null) sub.cancel();
- }
- _namedObservers.clear();
- _namedObservers = null;
- }
-
- /// Bind the [name] property in this element to [bindable]. *Note* in Dart it
- /// is necessary to also define the field:
- ///
- /// var myProperty;
- ///
- /// ready() {
- /// super.ready();
- /// bindProperty(#myProperty,
- /// new PathObserver(this, 'myModel.path.to.otherProp'));
- /// }
- Bindable bindProperty(Symbol name, bindableOrValue, {oneTime: false}) {
- // Dart note: normally we only reach this code when we know it's a
- // property, but if someone uses bindProperty directly they might get a
- // NoSuchMethodError either from the getField below, or from the setField
- // inside PolymerBinding. That doesn't seem unreasonable, but it's a slight
- // difference from Polymer.js behavior.
-
- _bindLog.fine(() => 'bindProperty: [$bindableOrValue] to [$_name].[$name]');
-
- if (oneTime) {
- if (bindableOrValue is Bindable) {
- _bindLog.warning(() =>
- 'bindProperty: expected non-bindable value n a one-time binding to '
- '[$_name].[$name], but found $bindableOrValue.');
- }
- smoke.write(this, name, bindableOrValue);
- return null;
- }
-
- return bindToAccessor(name, bindableOrValue, resolveBindingValue: true);
- }
-
- /// Attach event listeners on the host (this) element.
- void addHostListeners() {
- var events = _element._eventDelegates;
- if (events.isEmpty) return;
-
- _eventsLog.fine(() => '[$_name] addHostListeners: $events');
-
- // NOTE: host events look like bindings but really are not;
- // (1) we don't want the attribute to be set and (2) we want to support
- // multiple event listeners ('host' and 'instance') and Node.bind
- // by default supports 1 thing being bound.
- events.forEach((type, methodName) {
- // Dart note: the getEventHandler method is on our PolymerExpressions.
- PolymerGesturesJs.addEventListener(
- this, type,
- Zone.current.bindUnaryCallback(
- element.syntax.getEventHandler(this, this, methodName)));
- });
- }
-
- /// Calls [methodOrCallback] with [args] if it is a closure, otherwise, treat
- /// it as a method name in [object], and invoke it.
- void dispatchMethod(object, callbackOrMethod, List args) {
- _eventsLog.info(() => '>>> [$_name]: dispatch $callbackOrMethod');
-
- if (callbackOrMethod is Function) {
- int maxArgs = smoke.maxArgs(callbackOrMethod);
- if (maxArgs == -1) {
- _eventsLog.warning(
- 'invalid callback: expected callback of 0, 1, 2, or 3 arguments');
- }
- args.length = maxArgs;
- Function.apply(callbackOrMethod, args);
- } else if (callbackOrMethod is String) {
- smoke.invoke(object, smoke.nameToSymbol(callbackOrMethod), args,
- adjust: true);
- } else {
- _eventsLog.warning('invalid callback');
- }
-
- _eventsLog.fine(() => '<<< [$_name]: dispatch $callbackOrMethod');
- }
-
- /// Call [methodName] method on this object with [args].
- invokeMethod(Symbol methodName, List args) =>
- smoke.invoke(this, methodName, args, adjust: true);
-
- /// Invokes a function asynchronously.
- /// This will call `Polymer.flush()` and then return a `new Timer`
- /// with the provided [method] and [timeout].
- ///
- /// If you would prefer to run the callback using
- /// [window.requestAnimationFrame], see the [async] method.
- ///
- /// To cancel, call [Timer.cancel] on the result of this method.
- Timer asyncTimer(void method(), Duration timeout) {
- // Dart note: "async" is split into 2 methods so it can have a sensible type
- // signatures. Also removed the various features that don't make sense in a
- // Dart world, like binding to "this" and taking arguments list.
-
- // when polyfilling Object.observe, ensure changes
- // propagate before executing the async method
- scheduleMicrotask(Observable.dirtyCheck);
- PolymerJs.flush(); // for polymer-js interop
- return new Timer(timeout, method);
- }
-
- /// Invokes a function asynchronously. The context of the callback function is
- /// function is bound to 'this' automatically. Returns a handle which may be
- /// passed to cancelAsync to cancel the asynchronous call.
- ///
- /// If you would prefer to run the callback after a given duration, see
- /// the [asyncTimer] method.
- ///
- /// If you would like to cancel this, use [cancelAsync].
- int async(RequestAnimationFrameCallback method) {
- // when polyfilling Object.observe, ensure changes
- // propagate before executing the async method
- scheduleMicrotask(Observable.dirtyCheck);
- PolymerJs.flush(); // for polymer-js interop
- return window.requestAnimationFrame(method);
- }
-
- /// Cancel an operation scheduled by [async].
- void cancelAsync(int id) => window.cancelAnimationFrame(id);
-
- /// Fire a [CustomEvent] targeting [onNode], or `this` if onNode is not
- /// supplied. Returns the new event.
- CustomEvent fire(String type,
- {Object detail, Node onNode, bool canBubble, bool cancelable}) {
- var node = onNode != null ? onNode : this;
- var event = new CustomEvent(type,
- canBubble: canBubble != null ? canBubble : true,
- cancelable: cancelable != null ? cancelable : true,
- detail: detail);
- node.dispatchEvent(event);
- return event;
- }
-
- /// Fire an event asynchronously. See [async] and [fire].
- asyncFire(String type, {Object detail, Node toNode, bool canBubble}) {
- // TODO(jmesserly): I'm not sure this method adds much in Dart, it's easy to
- // add "() =>"
- async((x) =>
- fire(type, detail: detail, onNode: toNode, canBubble: canBubble));
- }
-
- /// Remove [className] from [old], add class to [anew], if they exist.
- void classFollows(Element anew, Element old, String className) {
- if (old != null) {
- old.classes.remove(className);
- }
- if (anew != null) {
- anew.classes.add(className);
- }
- }
-
- /// Installs external stylesheets and <style> elements with the attribute
- /// polymer-scope='controller' into the scope of element. This is intended
- /// to be called during custom element construction.
- void installControllerStyles() {
- var scope = findStyleScope();
- if (scope != null && !scopeHasNamedStyle(scope, localName)) {
- // allow inherited controller styles
- var decl = _element;
- var cssText = new StringBuffer();
- while (decl != null) {
- cssText.write(decl.cssTextForScope(_STYLE_CONTROLLER_SCOPE));
- decl = decl.superDeclaration;
- }
- if (cssText.isNotEmpty) {
- installScopeCssText('$cssText', scope);
- }
- }
- }
-
- void installScopeStyle(style, [String name, Node scope]) {
- if (scope == null) scope = findStyleScope();
- if (name == null) name = '';
-
- if (scope != null && !scopeHasNamedStyle(scope, '$_name$name')) {
- var cssText = new StringBuffer();
- if (style is Iterable) {
- for (var s in style) {
- cssText
- ..writeln(s.text)
- ..writeln();
- }
- } else {
- cssText = (style as Node).text;
- }
- installScopeCssText('$cssText', scope, name);
- }
- }
-
- void installScopeCssText(String cssText, [Node scope, String name]) {
- if (scope == null) scope = findStyleScope();
- if (name == null) name = '';
-
- if (scope == null) return;
-
- if (_hasShadowDomPolyfill) {
- cssText = _shimCssText(cssText, scope is ShadowRoot ? scope.host : null);
- }
- var style = element.cssTextToScopeStyle(cssText, _STYLE_CONTROLLER_SCOPE);
- applyStyleToScope(style, scope);
- // cache that this style has been applied
- styleCacheForScope(scope).add('$_name$name');
- }
-
- Node findStyleScope([node]) {
- // find the shadow root that contains this element
- var n = node;
- if (n == null) n = this;
- while (n.parentNode != null) {
- n = n.parentNode;
- }
- return n;
- }
-
- bool scopeHasNamedStyle(Node scope, String name) =>
- styleCacheForScope(scope).contains(name);
-
- Map _polyfillScopeStyleCache = {};
-
- Set styleCacheForScope(Node scope) {
- var styles;
- if (_hasShadowDomPolyfill) {
- var name = scope is ShadowRoot
- ? scope.host.localName
- : (scope as Element).localName;
- var styles = _polyfillScopeStyleCache[name];
- if (styles == null) _polyfillScopeStyleCache[name] = styles = new Set();
- } else {
- styles = _scopeStyles[scope];
- if (styles == null) _scopeStyles[scope] = styles = new Set();
- }
- return styles;
- }
-
- static final _scopeStyles = new Expando();
-
- static String _shimCssText(String cssText, [Element host]) {
- var name = '';
- var is_ = false;
- if (host != null) {
- name = host.localName;
- is_ = host.attributes.containsKey('is');
- }
- var selector = _ShadowCss.callMethod('makeScopeSelector', [name, is_]);
- return _ShadowCss.callMethod('shimCssText', [cssText, selector]);
- }
-
- static void applyStyleToScope(StyleElement style, Node scope) {
- if (style == null) return;
-
- if (scope == document) scope = document.head;
-
- if (_hasShadowDomPolyfill) scope = document.head;
-
- // TODO(sorvell): necessary for IE
- // see https://connect.microsoft.com/IE/feedback/details/790212/
- // cloning-a-style-element-and-adding-to-document-produces
- // -unexpected-result#details
- // var clone = style.cloneNode(true);
- var clone = new StyleElement()..text = style.text;
-
- var attr = style.attributes[_STYLE_SCOPE_ATTRIBUTE];
- if (attr != null) {
- clone.attributes[_STYLE_SCOPE_ATTRIBUTE] = attr;
- }
-
- // TODO(sorvell): probably too brittle; try to figure out
- // where to put the element.
- var refNode = scope.firstChild;
- if (scope == document.head) {
- var selector = 'style[$_STYLE_SCOPE_ATTRIBUTE]';
- var styleElement = document.head.querySelectorAll(selector);
- if (styleElement.isNotEmpty) {
- refNode = styleElement.last.nextElementSibling;
- }
- }
- scope.insertBefore(clone, refNode);
- }
-
- /// Invoke [callback] in [wait], unless the job is re-registered,
- /// which resets the timer. If [wait] is not supplied, this will use
- /// [window.requestAnimationFrame] instead of a [Timer].
- ///
- /// For example:
- ///
- /// _myJob = Polymer.scheduleJob(_myJob, callback);
- ///
- /// Returns the newly created job.
- // Dart note: renamed to scheduleJob to be a bit more consistent with Dart.
- PolymerJob scheduleJob(PolymerJob job, void callback(), [Duration wait]) {
- if (job == null) job = new PolymerJob._();
- // Dart note: made start smarter, so we don't need to call stop.
- return job..start(callback, wait);
- }
-
- // Deprecated: Please use injectBoundHtml.
- @deprecated
- DocumentFragment injectBoundHTML(String html, [Element element]) =>
- injectBoundHtml(html, element: element);
-
- /// Inject HTML which contains markup bound to this element into
- /// a target element (replacing target element content).
- DocumentFragment injectBoundHtml(String html, {Element element,
- NodeValidator validator, NodeTreeSanitizer treeSanitizer}) {
- var template = new TemplateElement()
- ..setInnerHtml(html, validator: validator, treeSanitizer: treeSanitizer);
- var fragment = this.instanceTemplate(template);
- if (element != null) {
- element.text = '';
- element.append(fragment);
- }
- return fragment;
- }
-}
-
-// Dart note: this is related to _bindOldStylePublishedProperty. Polymer
-// addresses n-way bindings by metaprogramming: redefine the property on the
-// PolymerElement instance to always get its value from the model@path. This is
-// supported in Dart using a new style of @published property declaration using
-// the `readValue` and `writeValue` methods above. In the past we used to work
-// around this by listening to changes on both sides and updating the values.
-// This object provides the hooks to do this.
-// TODO(sigmund,jmesserly): delete after a deprecation period.
-class _PolymerBinding extends Bindable {
- final Polymer _target;
- final Symbol _property;
- final Bindable _bindable;
- StreamSubscription _sub;
- Object _lastValue;
-
- _PolymerBinding(this._target, this._property, this._bindable) {
- _sub = _target.changes.listen(_propertyValueChanged);
- _updateNode(open(_updateNode));
- }
-
- void _updateNode(newValue) {
- _lastValue = newValue;
- smoke.write(_target, _property, newValue);
- // Note: we don't invoke emitPropertyChangeRecord here because that's
- // done by listening on changes on the PolymerElement.
- }
-
- void _propertyValueChanged(List<ChangeRecord> records) {
- for (var record in records) {
- if (record is PropertyChangeRecord && record.name == _property) {
- final newValue = smoke.read(_target, _property);
- if (!identical(_lastValue, newValue)) {
- this.value = newValue;
- }
- return;
- }
- }
- }
-
- open(callback(value)) => _bindable.open(callback);
- get value => _bindable.value;
- set value(newValue) => _bindable.value = newValue;
-
- void close() {
- if (_sub != null) {
- _sub.cancel();
- _sub = null;
- }
- _bindable.close();
- }
-}
-
-// Ported from an inline object in instance/properties.js#bindToAccessor.
-class _CloseOnlyBinding extends Bindable {
- final _PropertyAccessor accessor;
-
- _CloseOnlyBinding(this.accessor);
-
- open(callback) {}
- get value => null;
- set value(newValue) {}
- deliver() {}
-
- void close() {
- if (accessor.bindable == null) return;
- accessor.bindable.close();
- accessor.bindable = null;
- }
-}
-
-bool _toBoolean(value) => null != value && false != value;
-
-final Logger _observeLog = new Logger('polymer.observe');
-final Logger _eventsLog = new Logger('polymer.events');
-final Logger _unbindLog = new Logger('polymer.unbind');
-final Logger _bindLog = new Logger('polymer.bind');
-final Logger _watchLog = new Logger('polymer.watch');
-final Logger _readyLog = new Logger('polymer.ready');
-
-final Expando _eventHandledTable = new Expando<Set<Node>>();
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