在 TypeScript 中的靜態方法和實例方法

您可以在 Mongoose 模型上定義實例方法和靜態函式。透過一些額外的設定，您也可以在 TypeScript 中註冊方法和靜態函式。

實例方法

若要在 TypeScript 中定義實例方法，請建立一個新的介面，代表您的實例方法。您需要將該介面作為 Schema 建構子的第三個泛型參數，並且作為 Model 的第三個泛型參數傳遞，如下所示。

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'

靜態方法

Mongoose 模型對於靜態方法沒有明確的泛型參數。如果您的模型有靜態方法，我們建議建立一個介面，擴展 Mongoose 的 Model 介面，如下所示。

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 現在支援自動類型化的靜態函式，它已在模式選項中提供。靜態函式可以定義如下

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

實例方法和靜態方法

以下是如何定義同時具有實例方法和靜態方法的模型。

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'
});