RFC: introduce dart:js

sdk/lib/js/dart2js/js_dart2js.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.
+
+library dart.js;
+
+import 'dart:_foreign_helper' show JS;
+import 'dart:_js_helper' show convertDartClosureToJS;
+
+JsObject get context {
+  return new JsObject._fromJs(JS('=Object', 'window'));
+}
+
+scoped(f) => f();
+
+dynamic retain(Serializable<JsObject> object) {}
+void release(Serializable<JsObject> object) {}
+
+JsObject jsify(dynamic data) => data == null ? null : new JsObject._json(data);
+
+class Callback implements Serializable<JsFunction> {
+  final Function _f; // here to allow capture in closure
+  final bool _withThis; // here to allow capture in closure
+  dynamic _jsFunction;
+
+  Callback._internal(this._f, this._withThis) {
+    _jsFunction = JS('=Object', r'''
+(function(){
+  var f = #;
+  return function(){
+    return f(this, Array.prototype.slice.apply(arguments));
+  };
+}).apply(this)''', convertDartClosureToJS(_call, 2));
+  }
+
+  _call(thisArg, List args) {
+    final arguments = new List.from(args);
+    if (_withThis) arguments.insert(0, thisArg);
+    final dartArgs = arguments.map(_convertToDart).toList();
+    return _convertToJS(Function.apply(_f, dartArgs));
+  }
+
+  JsFunction toJs() => new JsFunction._fromJs(_jsFunction);
+
+  dispose() {}
+
+  factory Callback.once(Function f, {bool withThis: false}) =>
+      new Callback._internal(f, withThis);
+
+  factory Callback.many(Function f, {bool withThis: false}) =>
+      new Callback._internal(f, withThis);
+}
+
+class JsObject implements Serializable<JsObject> {
+  final dynamic _jsObject;
+
+  JsObject._fromJs(this._jsObject);
+
+  factory JsObject(Serializable<JsFunction> constructor, [List arguments]) {
+    final constr = _convertToJS(constructor);
+    if (arguments == null) {
+      return new JsObject._fromJs(JS('=Object', 'new #()', constr));
+    }
+    final args = arguments.map(_convertToJS).toList();
+    switch (args.length) {
+      case 0:
+        return new JsObject._fromJs(JS('=Object', 'new #()', constr));
+      case 1:
+        return new JsObject._fromJs(JS('=Object', 'new #(#)', constr, args[0]));
+      case 2:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#)', constr, args[0],
+            args[1]));
+      case 3:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#)', constr,
+            args[0], args[1], args[2]));
+      case 4:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#)', constr,
+            args[0], args[1], args[2], args[3]));
+      case 5:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#,#)', constr,
+            args[0], args[1], args[2], args[3], args[4]));
+      case 6:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#,#,#)', constr,
+            args[0], args[1], args[2], args[3], args[4], args[5]));
+      case 7:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#,#,#,#)',
+            constr, args[0], args[1], args[2], args[3], args[4], args[5],
+            args[6]));
+      case 8:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#,#,#,#,#)',
+            constr, args[0], args[1], args[2], args[3], args[4], args[5],
+            args[6], args[7]));
+      case 9:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#,#,#,#,#,#)',
+            constr, args[0], args[1], args[2], args[3], args[4], args[5],
+            args[6], args[7], args[8]));
+      case 10:
+        return new JsObject._fromJs(JS('=Object', 'new #(#,#,#,#,#,#,#,#,#,#)',
+            constr, args[0], args[1], args[2], args[3], args[4], args[5],
+            args[6], args[7], args[8], args[9]));
+    }
+    return new JsObject._fromJs(JS('=Object', r'''(function(){
+var Type = function(){};
+Type.prototype = #.prototype;
+var instance = new Type();
+ret = constructor.apply(instance, #);

[vsm, 2013/06/11 16:17:44]

'constructor' isn't in scope here.  I think you need to pass constr in here
again.

Can you add a test for this path?

[alexandre.ardhuin, 2013/06/12 21:29:19]

Done.

+ret = Object(ret) === ret ? ret : instance;
+})()''', constr, args));
+  }
+
+  factory JsObject._json(data) => new JsObject._fromJs(_convertDataTree(data));
+
+  static _convertDataTree(data) {
+    if (data is Map) {
+      final convertedData = JS('=Object', '{}');
+      for (var key in data.keys) {
+        JS('=Object', '#[#]=#', convertedData, key,
+            _convertDataTree(data[key]));
+      }
+      return convertedData;
+    } else if (data is Iterable) {
+      return data.map(_convertDataTree).toList();
+    } else {
+      return _convertToJS(data);
+    }
+  }
+
+  JsObject toJs() => this;
+
+  operator[](key) => _convertToDart(JS('=Object', '#[#]', _convertToJS(this), key));

[vsm, 2013/06/11 16:17:44]

Nit: line length > 80

[alexandre.ardhuin, 2013/06/12 21:29:19]

Done.

+  operator[]=(key, value) => JS('void', '#[#]=#', _convertToJS(this), key,
+      _convertToJS(value));
+
+  operator==(other) => identical(this, other) ||
+      (other is JsObject && JS('bool', '# == #', _convertToJS(this),
+          _convertToJS(other)));
+
+  bool hasProperty(String property) => JS('bool', '# in #', property,
+      _convertToJS(this));
+
+  void deleteProperty(String name) {
+    JS('void', 'delete #[#]', _convertToJS(this), name);
+  }
+
+  bool instanceof(Serializable<JsFunction> type) =>
+      JS('bool', '# instanceof #', _convertToJS(this), _convertToJS(type));
+
+  String toString() {
+    try {
+      return JS('String', '#.toString()', _convertToJS(this));
+    } catch(e) {
+      return super.toString();
+    }
+  }
+
+  callMethod(String name, [List args]) =>
+      _convertToDart(JS('=Object', '#[#].apply(#, #)', _convertToJS(this), name,
+          _convertToJS(this),
+          args == null ? null : args.map(_convertToJS).toList()));
+}
+
+class JsFunction extends JsObject implements Serializable<JsFunction> {
+  JsFunction._fromJs(jsObject) : super._fromJs(jsObject);
+  apply(thisArg, [List args]) =>
+      _convertToDart(JS('=Object', '#.apply(#, #)', _convertToJS(this),
+          _convertToJS(thisArg),
+          args == null ? null : args.map(_convertToJS).toList()));
+}
+
+abstract class Serializable<T> {
+  T toJs();
+}
+
+class _DartProxy {
+  dynamic o;
+  _DartProxy(this.o);
+}
+
+dynamic _convertToJS(dynamic o) {
+  if (o == null) {
+    return null;
+  } else if (o is String || o is num || o is bool) {
+    return o;
+  } else if (o is JsObject) {
+    return o._jsObject;
+  } else if (o is Serializable) {
+    return _convertToJS(o.toJs());
+  } else {
+    return new _DartProxy(o);
+  }
+}

[vsm, 2013/06/11 16:17:44]

Nit: space between functions.

[alexandre.ardhuin, 2013/06/12 21:29:19]

Done.

+dynamic _convertToDart(dynamic o) {
+  if (o == null) {
+    return null;
+  } else if (o is num || o is String || o is bool) {
+    return o;
+  } else if (JS('bool', '# instanceof Function', o)) {
+    return new JsFunction._fromJs(JS('Function', '#', o));

[vsm, 2013/06/11 16:17:44]

I think this should be JS('=Object', ...) as well.  It's not a Dart Function.

[alexandre.ardhuin, 2013/06/12 21:29:19]

Done.

+  } else if (o is _DartProxy) {
+    return o.o;
+  } else {
+    return new JsObject._fromJs(JS('=Object', '#', o));
+  }
+}
+
+int proxyCount({all: false, dartOnly: false, jsOnly: false}) => 0;