未捕获的TypeError:无法添加属性12，对象不可扩展 [英] Uncaught TypeError: Can't add property 12, object is not extensible

问题描述

我似乎无法理解我在客户端应用程序上遇到的错误.我正在订阅graphql订阅，并且能够检索更新，但是无法将更改推送到绑定到视图的打字稿数组"models:ModelClass []".

I can't seem to understand the error I am getting on my client application. I am subscribing to a graphql subscription and I am able to retrieve the updates but I am not being able to push the changes to the typescript array called "models:ModelClass[]" which is bound to the view.

我有什么想念的或者做错了吗?

Is there something I am missing or doing wrong?

models.component.ts

this.apollo.subscribe({
  query: gql`
    subscription {
      newModelCreated{
        _id
        name
        type
        train_status
        deploy_status
        data_path
        description
        created_at
        updated_at
      }
    }
  `
}).subscribe((data) => {
  console.log("CREATED: " + JSON.stringify(data.newModelCreated));
  console.log(data.newModelCreated);
  var temp:ModelClass = data.newModelCreated;
  this.models.push(temp);
});

model-class.ts

export interface ModelClass {
    _id: string;
    name: string;
    type: string;
    parameters: {
        alpha: number;
    };
    train_status: string;
    deploy_status: string;
    test_accuracy: string;
    created_at: number;
    updated_at: number;
}

推荐答案

我想this.models是Apollo返回的数组，您想将新创建的对象添加到初始数组中吗?如果为true，则Apollo返回一个不可变的Object！

I suppose this.models is an array returned by Apollo and you want to add new created object to your initial array ? If true, Apollo returns an immutable Object !

您必须克隆初始返回的数组.订阅功能中的内容:

You have to clone the initial returned array. Something like in the subscribe function:

this.apollo
    .watchQuery({query: INITIAL_GQL_REQUEST})
    .subscribe((data) => {
        this.models = data.models.map((model) => {
            return {
                id: model.id, 
                name: model.name,
                another: model.another
            }
        })
    };
});

然后，您的订阅请求将能够将创建的模型添加到此简单的javascript数组.

Then your subscription request will be able to add a created model to this plain javascript array.

PS:不确定，但我想Apollo返回不可变对象，因为它们存储在商店中，并且根据您的提取策略，如果您能够对其进行突变，它可能会错过商店匹配.

PS: Not sure but I suppose Apollo returns immutable objects because they are stored in the store and depending on your fetch policy, it can miss store hits if your are able to mutate them.

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