TypeScript 中的静态和方法

¥Statics and Methods in TypeScript

你可以在 Mongoose 模型上定义实例方法和静态函数。通过一些额外的配置，你还可以在 TypeScript 中注册方法和静态。

¥You can define instance methods and static functions on Mongoose models. With a little extra configuration, you can also register methods and statics in TypeScript.

方法

¥Methods

要在 TypeScript 中定义 实例方法，请创建一个表示实例方法的新接口。你需要将该接口作为第三个通用参数传递给 Schema 构造函数，并作为第三个通用参数传递给 Model，如下所示。

¥To define an instance method in TypeScript, create a new interface representing your instance methods. You need to pass that interface as the 3rd generic parameter to the Schema constructor and as the 3rd generic parameter to Model as shown below.

import { Model, Schema, model } from 'mongoose';

interface IUser {
  firstName: string;
  lastName: string;
}

// Put all user instance methods in this interface:
interface IUserMethods {
  fullName(): string;
}

// Create a new Model type that knows about IUserMethods...
type UserModel = Model<IUser, {}, IUserMethods>;

// And a schema that knows about IUserMethods
const schema = new Schema<IUser, UserModel, IUserMethods>({
  firstName: { type: String, required: true },
  lastName: { type: String, required: true }
});
schema.method('fullName', function fullName() {
  return this.firstName + ' ' + this.lastName;
});

const User = model<IUser, UserModel>('User', schema);

const user = new User({ firstName: 'Jean-Luc', lastName: 'Picard' });
const fullName: string = user.fullName(); // 'Jean-Luc Picard'

静态

¥Statics

Mongoose models 没有 statics 的显式通用参数。如果你的模型有静态，我们建议创建一个 extends Mongoose 的 Model 接口的接口，如下所示。

¥Mongoose models do not have an explicit generic parameter for statics. If your model has statics, we recommend creating an interface that extends Mongoose's Model interface as shown below.

import { Model, Schema, model } from 'mongoose';

interface IUser {
  name: string;
}

interface UserModel extends Model<IUser> {
  myStaticMethod(): number;
}

const schema = new Schema<IUser, UserModel>({ name: String });
schema.static('myStaticMethod', function myStaticMethod() {
  return 42;
});

const User = model<IUser, UserModel>('User', schema);

const answer: number = User.myStaticMethod(); // 42

Mongoose 现在确实支持自动类型静态函数，因为它是在结构选项中提供的。静态函数可以定义如下：

¥Mongoose does support auto typed static functions now that it is supplied in schema options. Statics functions can be defined as following:

import { Schema, model } from 'mongoose';

const schema = new Schema(
  { name: String },
  {
    statics: {
      myStaticMethod() {
        return 42;
      }
    }
  }
);

const User = model('User', schema);

const answer = User.myStaticMethod(); // 42

方法和静力学

¥Both Methods and Statics

以下是如何定义具有方法和静态的模型。

¥Below is how you can define a model that has both methods and statics.

import { Model, Schema, HydratedDocument, model } from 'mongoose';

interface IUser {
  firstName: string;
  lastName: string;
}

interface IUserMethods {
  fullName(): string;
}

interface UserModel extends Model<IUser, {}, IUserMethods> {
  createWithFullName(name: string): Promise<HydratedDocument<IUser, IUserMethods>>;
}

const schema = new Schema<IUser, UserModel, IUserMethods>({
  firstName: { type: String, required: true },
  lastName: { type: String, required: true }
});
schema.static('createWithFullName', function createWithFullName(name: string) {
  const [firstName, lastName] = name.split(' ');
  return this.create({ firstName, lastName });
});
schema.method('fullName', function fullName(): string {
  return this.firstName + ' ' + this.lastName;
});

const User = model<IUser, UserModel>('User', schema);

User.createWithFullName('Jean-Luc Picard').then(doc => {
  console.log(doc.firstName); // 'Jean-Luc'
  doc.fullName(); // 'Jean-Luc Picard'
});