Question

我目前正在尝试基于我从ajax调用获得的json创建一个对象。它看起来像这样：

{
    "users": [
        {
            "address": {
                "city": "testCity", 
                "houseNumber": 69, 
                "id": 1, 
                "postcode": 420, 
                "street": "testStreet"
            }, 
            "email": "testEmail@test.de", 
            "gender": "male", 
            "id": 3, 
            "isAdmin": false, 
            "lastname": "testLastname", 
            "prename": "testPrename", 
            "projects": [
                {
                    "archived": null, 
                    "files": [], 
                    "id": 1, 
                    "name": "testProject", 
                    "timestamp": "2017-01-27T20:23:06+00:00", 
                    "uri": "http://localhost:2000/api/projects/1"
                }
            ], 
            "uri": "http://localhost:2000/api/users/3"
        }
    ]
}

我在User类中定义了一个静态方法，用于从该输入创建User类型的对象。我正在寻找的是一种创建类Project和Address的对象的方法，并将它们设置为User Class中的相应字段。这就是我目前所拥有的：

export class User {
    public uri: string = undefined;
    public id: number = undefined;
    public readonly isAdmin: boolean = undefined;

    public prename: string = undefined;
    public lastname: string = undefined;
    public gender: string = undefined;
    public email: string = undefined;
    private password: string = undefined;

    public address: Address = undefined;
    public projects: Project[] = undefined;

    constructor() {

    }

    // Returns an array containing one or more User objects
    public static load(res: Response): User[]{
        let data: Object = res.json();
        let users: User[] = [];

        // Payload contains multiple Users (array)
        if(data.hasOwnProperty('users')){
            let dataUsers: Object[] = data['users'];

            for(let dataUser of dataUsers){
                let user = new User();

                for(let key in user){
                    if(dataUser.hasOwnProperty(key)){
                        if(typeof dataUser[key] === 'object'){
                            // If it's an object, find the class that matches the 'content' of the object and call their load method 
                            }
                        } else {
                            user[key] = dataUser[key];
                        }
                    }
                }

                users.push(user);
            }
        // Payload contains a single User
        } else if(data.hasOwnProperty('user')){
            let dataUser = data['user'];
            let user = new User();

            for(let key in user){
                if(data.hasOwnProperty(key)){
                    user[key] = dataUser[key];
                }
            }

            users.push(user);
        } else {
            users.push(new User());
        }

        return users;
    }

一种方法是通过检查密钥是“项目”还是“地址”来硬编码地址和项目的对象创建，但我正在寻找一种更“动态”的方式来点缀它。

Answer 1

您可以将加载函数存储在地图中。它看起来像这样。

class Address {
    static load(data:Object) {
        //...
    }
}

class Project {
    static load(data:Object) {

    }
}

let keyClassMap : { [id:string]: (data:Object) => any } = {
    address: Address.load,
    project: Project.load,
}

此对象的键是与您感兴趣的类定义相对应的键。

然后在你的陈述中你可以做到：

if(typeof dataUser[key] === 'object'){
    user[key] = keyClassMap[key](dataUser[key]);
}

动态选择类来创建对象

1 个答案: