Question

有没有办法将JSON字符串解析为现有的Javascript对象：假设我创建了这个对象：

var ClientState = function(){
    this.userId ="";
    this.telephoneState = "UNKNOWN";
    this.agentState = "UNKNOWN";
    this.muteState = "UNKNOWN";
    this.number = "";
    this.ready = false;
}

ClientState.prototype = {
    doNastyStuff: function(){
        //do something here
    }
    //other methods here
}

我有这个json通过电线：

{"userId":"xyz","telephoneState":"READY","agentState":"UNKNOWN","muteState":"MUTED","number":"","ready":false}

是否可以反序列化为上面指定的对象？这样我就可以使用它上面指定的所有方法了吗？或者通常可以反序列化为特定的目标对象（不指定此目标对象中的反序列化）？（我知道我可以创建一个接受json或解析对象的构造函数。）

Answer 1

是的！您可以使用Object.assign用另一个对象覆盖对象的属性：

＆＃13;

var ClientState = function() {
  this.userId = "";
  this.telephoneState = "UNKNOWN";
  this.agentState = "UNKNOWN";
  this.muteState = "UNKNOWN";
  this.number = "";
  this.ready = false;
}

var c = new ClientState();
console.log('prior assignment: ', c);

Object.assign(c, {
  "userId": "xyz",
  "telephoneState": "READY",
  "agentState": "UNKNOWN",
  "muteState": "MUTED",
  "number": "",
  "ready": false
});

console.log('after assignment: ', c);

＆＃13;

请注意，它将通过匹配相应的键来覆盖源对象（第一个对象）与目标对象（第二个对象）的所有属性。目标对象中不存在的键在源对象中保持不变。

Answer 2

这是你的想法吗？

function parseAs(targetClass, rawJSON) {
    return Object.assign(new targetClass(), JSON.parse(rawJSON));
}

var clientState = parseAs(ClientState, '{"userId":"xyz"}');

我不认为有这样的原生JSON方法可以做到这一点，但你可以写一个像上面那样的函数。您甚至可以在JSON类本身上定义它：

JSON.parseAs = function(targetClass, rawJSON) {
    return Object.assign(new targetClass(), JSON.parse(rawJSON));
}

Answer 3

如果要使用函数将对象值添加到实例属性：

function ClientState() {
  this.userId = "";
  this.telephoneState = "UNKNOWN";
  this.agentState = "UNKNOWN";
  this.muteState = "UNKNOWN";
  this.number = "";
  this.ready = false;
}

ClientState.prototype = {
  doNastyStuff: function(json) {
    const data = JSON.parse(json);
    Object.assign(this, data);
  }
}

const json = '{"userId":"xyz","telephoneState":"READY","agentState":"UNKNOWN","muteState":"MUTED","number":"","ready":false}';
const clientState = new ClientState();
clientState.doNastyStuff(json);
console.log(clientState);

将JSON反序列化为特定/现有JavaScript对象

3 个答案: