如何通过类转换器识别子对象？

【问题标题】：how to identify a child object by class-transformer ? | Nest.js如何通过类转换器识别子对象？ | Nest.js
【发布时间】：2021-04-19 10:43:07
【问题描述】：

我正在尝试使用库“class-transformer”将 json 主体解析为 JavaScript 对象，但他无法识别我的子对象。

这是json文件：

{
  "shops": [{
      "shopId": 1,
      "name": "La piscine Marius-Leclercq",
      "address": "99 Avenue Barbusse, 62440 Harnes",
      "description": "La piscine Marius-Leclercq est située en plein centre de la ville dans la rue Barbusse. Différentes spécialités sportives y sont proposées. Un bassin de 25 mètres de long vous accueille du lundi au dimanche ainsi qu’un petit bain pour les activités comme l’aquagym, l’aquadouce ou le jardin aquatique.",
      "email": "piscinemariusleclercq@contact.fr",
      "phone": "03 21 13 96 00",
      "localisation": {
        "lat": 50.450157165527344,
        "long": 2.898190498352051
      },
      "vidoLink": "https://www.youtube.com/watch?v=rqDEgCBYMxA&ab_channel=AvallonVision",
      "pictures": [{
          "idPicture": 1,
          "link": "https://zupimages.net/up/21/02/cpri.jpg"
        },
        {
          "idPicture": 2,
          "link": "https://zupimages.net/up/21/02/3mkk.jpg"
        }
      ],
      "openShop": [{
          "dayWeek": "Monday",
          "hourStart": "12:00:00",
          "endHour": "13:00:00"
        },
        {
          "dayWeek": "Monday",
          "hourStart": "16:15:00",
          "endHour": "19:00:00"
        },
        {
          "dayWeek": "Tuesday",
          "hourStart": "16:15:00",
          "endHour": "19:00:00"
        },
        {
          "dayWeek": "Thursday",
          "hourStart": "10:00:00",
          "endHour": "13:30:00"
        },
        {
          "dayWeek": "Thursday",
          "hourStart": "14:00:00",
          "endHour": "19:15:00"
        },
        {
          "dayWeek": "Saturday",
          "hourStart": "10:00:00",
          "endHour": "12:00:00"
        },
        {
          "dayWeek": "Saturday",
          "hourStart": "14:00:00",
          "endHour": "17:00:00"
        },
        {
          "dayWeek": "Sunday",
          "hourStart": "8:00:00",
          "endHour": "12:00:00"
        }

      ]
    },
    {
      "shopId": 2,
      "name": "Climb up",
      "address": "Plaine sportive, 110 Rue Jean Jaurès, 59810 Lesquin",
      "description": "Depuis plus de 15 ans nous cultivons la diversité au sein de nos structures. Diversité de profils, de visions et de sensibilités. Nos nombreux échanges ont ainsi donné jour à un concept de salles d’escalade pensées comme des lieux de vie ouverts à tous.",
      "email": "climbup@contact.fr",
      "phone": "03 20 07 57 42",
      "localisation": {
        "lat": 50.5865602,
        "long": 3.1071495
      },
      "vidoLink": "https://www.youtube.com/watch?v=3-3a9GghAR0&ab_channel=ClimbUp",
      "pictures": [{
          "idPicture": 3,
          "link": "https://zupimages.net/up/21/02/z8st.jpg"
        },
        {
          "idPicture": 4,
          "link": "https://zupimages.net/up/21/02/6yh3.jpg"
        }
      ],
      "openShop": [{
          "dayWeek": "Monday",
          "hourStart": "8:00:00",
          "endHour": "23:00:00"
        },
        {
          "dayWeek": "Tuesday",
          "hourStart": "8:00:00",
          "endHour": "23:00:00"
        },
        {
          "dayWeek": "Wednesday",
          "hourStart": "8:00:00",
          "endHour": "23:00:00"
        },
        {
          "dayWeek": "Thursday",
          "hourStart": "8:00:00",
          "endHour": "23:00:00"
        },
        {
          "dayWeek": "Friday",
          "hourStart": "8:00:00",
          "endHour": "23:00:00"
        },
        {
          "dayWeek": "Saturday",
          "hourStart": "10:00:00",
          "endHour": "23:00:00"
        },
        {
          "dayWeek": "Sunday",
          "hourStart": "8:00:00",
          "endHour": "12:00:00"
        }
      ]
    }
  ]
}

有我的 DTO：

export class ShopEntity {
    shops : ShopDto[];
}

export class ShopDto {
  @Expose({
    name: 'shopId'
  })
  id: number;
  name: string;
  address: string;
  description: string;
  email: string;
  phone: string;
  localisation: {
    lat: number;
    long: number;
  }
  videoLink: string;
  offers: OfferDto[];
  pictures: PictureDto[];
  openShop: OpenShopDto[];
}

这是我的代码行：

 let shopsTab = plainToClass(ShopEntity, body);

我成功从 ShopEntity 获取了我的第一个对象，但标签商店未定义。

【问题讨论】：

什么是“身体”？可以分享一下服务和控制器方法吗

标签： javascript nestjs class-transformer

【解决方案1】：

对于您的所有子对象，您应该添加@Type(() => ChildObjectType)。由于泛型在打字稿中的反映方式，数组不会序列化。作为一般规则，当我在 class-transformer 中处理子对象时，我一定要添加 @Type() 装饰器。

【讨论】：