javascript - 如何构造 Immutable.Record 的子类？

Question

class Event extends Immutable.Record {
  constructor(text) {
    super({text: text, timestamp: Date.now()});
  }
}

调用 new Event() 似乎返回一个构造函数:

new Event('started').toString()

"function Record(values){ if(values instanceof RecordType){ return values;}

if(!(this instanceof RecordType)){ return new RecordType(values);}

if(!hasInitialized){ hasInitialized=true; var keys=Object.keys(defaultValues); setProps(RecordTypePrototype,keys); RecordTypePrototype.size=keys.length; RecordTypePrototype._name=name; RecordTypePrototype._keys=keys; RecordTypePrototype._defaultValues=defaultValues;}

this._map=Map(values);}"

而调用该函数会返回预期的输出:

new Event('started')().toString()

"Record { "text": "started", "timestamp": 1453374580203 }"

我做错了什么？

Answer 1

Immutable.Record "Creates a new Class which produces Record instances ."，换句话说，它本身就是一个函数，你传递允许的键并返回一个你可以扩展的类；

class Event extends Immutable.Record({text:'', timestamp:''}) {
  constructor(text) {
    super({text: text, timestamp: Date.now()});
  }
}

> new Event('started').toString()
Event { "text": "started", "timestamp": 1453376445769 }