如何将JavaScript对象转换为Dart Map？

Question

我正在寻找一些逆转new JsObject.jsify.什么,将javascript转换Object回Dart Map是否有可用的东西？

我知道我可以使用JSON转换为字符串,但这并不涉及Object包含s函数,Dart对象,Dom Elements等的转移......有没有更好的方法？

Answer 1

这是一个适合处理JsObject类似的适配器Map<String, dynamic>:

import 'dart:collection' show Maps;
import 'dart:js';

class JsMap implements Map<String,dynamic> {
  final JsObject _jsObject;
  JsMap.fromJsObject(this._jsObject);

  operator [](String key) => _jsObject[key];
  void operator []=(String key, value) {
    _jsObject[key] = value;
  }
  remove(String key) {
    final value = this[key];
    _jsObject.deleteProperty(key);
    return value;
  }
  Iterable<String> get keys => context['Object'].callMethod('keys', [_jsObject]);

  // use Maps to implement functions
  bool containsValue(value) => Maps.containsValue(this, value);
  bool containsKey(String key) => keys.contains(key);
  putIfAbsent(String key, ifAbsent()) => Maps.putIfAbsent(this, key, ifAbsent);
  void addAll(Map<String, dynamic> other) {
    if (other != null) {
      other.forEach((k,v) => this[k] = v);
    }
  }
  void clear() => Maps.clear(this);
  void forEach(void f(String key, value)) => Maps.forEach(this, f);
  Iterable get values => Maps.getValues(this);
  int get length => Maps.length(this);
  bool get isEmpty => Maps.isEmpty(this);
  bool get isNotEmpty => Maps.isNotEmpty(this);
}

Answer 2

您可以生成json并对其进行解析：

    Map map = JSON.decode(
       context['JSON'].callMethod(
           'stringify',
           [context['map']]
       )
    );

Answer 3

如果你想深入处理并处理其他情况,那么简单的映射和保留函数(与json解决方案不同)然后使用这个简单的函数:

_toDartSimpleObject(thing) {
 if (thing is js.JsArray) {
  List res = new List();
  js.JsArray a = thing as js.JsArray;
  a.forEach((otherthing) {
    res.add(_toDartSimpleObject(otherthing));
  });
  return res;

 } else if (thing is js.JsObject) {
  Map res = new Map();
  js.JsObject o = thing as js.JsObject;
  Iterable<String> k = js.context['Object'].callMethod('keys', [o]);
   k.forEach((String k) {
   res[k] = _toDartSimpleObject(o[k]);
  });
  return res;

 } else {
  return thing;
 }
}