| // 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. |
| |
| // Patch file for dart:convert library. |
| |
| import 'dart:_foreign_helper' show JS; |
| import 'dart:_interceptors' show JSExtendableArray; |
| |
| /** |
| * Parses [json] and builds the corresponding parsed JSON value. |
| * |
| * Parsed JSON values Nare of the types [num], [String], [bool], [Null], |
| * [List]s of parsed JSON values or [Map]s from [String] to parsed |
| * JSON values. |
| * |
| * The optional [reviver] function, if provided, is called once for each object |
| * or list property parsed. The arguments are the property name ([String]) or |
| * list index ([int]), and the value is the parsed value. The return value of |
| * the reviver will be used as the value of that property instead of the parsed |
| * value. The top level value is passed to the reviver with the empty string as |
| * a key. |
| * |
| * Throws [FormatException] if the input is not valid JSON text. |
| */ |
| patch _parseJson(String source, reviver(var key, var value)) { |
| if (source is! String) throw new ArgumentError(source); |
| |
| var parsed; |
| try { |
| parsed = JS('=Object|JSExtendableArray|Null|bool|num|String', |
| 'JSON.parse(#)', |
| source); |
| } catch (e) { |
| throw new FormatException(JS('String', 'String(#)', e)); |
| } |
| |
| return _convertJsonToDart(parsed, reviver); |
| } |
| |
| /** |
| * Walks the raw JavaScript value [json], replacing JavaScript Objects with |
| * Maps. [json] is expected to be freshly allocated so elements can be replaced |
| * in-place. |
| */ |
| _convertJsonToDart(json, reviver(key, value)) { |
| |
| var revive = reviver == null ? (key, value) => value : reviver; |
| |
| walk(e) { |
| // JavaScript null, string, number, bool are in the correct representation. |
| if (JS('bool', '# == null', e) || JS('bool', 'typeof # != "object"', e)) { |
| return e; |
| } |
| |
| // This test is needed to avoid identifing '{"__proto__":[]}' as an Array. |
| // TODO(sra): Replace this test with cheaper '#.constructor === Array' when |
| // bug 621 below is fixed. |
| if (JS('bool', 'Object.getPrototypeOf(#) === Array.prototype', e)) { |
| var list = JS('JSExtendableArray', '#', e); // Teach compiler the type is known. |
| // In-place update of the elements since JS Array is a Dart List. |
| for (int i = 0; i < list.length; i++) { |
| // Use JS indexing to avoid range checks. We know this is the only |
| // reference to the list, but the compiler will likely never be able to |
| // tell that this instance of the list cannot have its length changed by |
| // the reviver even though it later will be passed to the reviver at the |
| // outer level. |
| var item = JS('', '#[#]', list, i); |
| JS('', '#[#]=#', list, i, revive(i, walk(item))); |
| } |
| return list; |
| } |
| |
| // Otherwise it is a plain Object, so copy to a Map. |
| var keys = JS('JSExtendableArray', 'Object.keys(#)', e); |
| Map map = {}; |
| for (int i = 0; i < keys.length; i++) { |
| String key = keys[i]; |
| map[key] = revive(key, walk(JS('', '#[#]', e, key))); |
| } |
| // V8 has a bug with properties named "__proto__" |
| // https://code.google.com/p/v8/issues/detail?id=621 |
| var proto = JS('', '#.__proto__', e); |
| // __proto__ can be undefined on IE9. |
| if (JS('bool', |
| 'typeof # !== "undefined" && # !== Object.prototype', |
| proto, proto)) { |
| map['__proto__'] = revive('__proto__', walk(proto)); |
| } |
| return map; |
| } |
| |
| return revive(null, walk(json)); |
| } |