扩展模式猫鼬中的“虚拟”继承方法不起作用答案

【问题标题】：Inheritance method "virtual" in extend schema mongoose doesn't work扩展模式猫鼬中的“虚拟”继承方法不起作用
【发布时间】：2021-04-03 18:12:15
【问题描述】：

我在模型UserSchema中有以下方法：

userSchema.virtual('password')
    .set(function(password) {
            this._password = password;
            this.salt = this.makeSalt();
            this.hashed_password = this.encryptPassword(password);
    })
    .get(function() {
            return this._password;
    }
);

但是当我创建新的teacher 时出现错误hashed_password is required。所以我认为userSchema 中的virtual 方法不是teacherSchema 中的继承。如何从userSchema 设置teacherSchema 继承方法，如virtual？

型号

const mongoose = require('mongoose');
extend = require('mongoose-extend-schema');
const Schema = mongoose.Schema;

const userSchema = new Schema({
    name: {
        type: String,
        trim: true,
        required: true,
        maxLength: 32
    },
    surname: {
        type: String,
        trim: true,
        required: true,
        maxLength: 32
    },
    email: {
        type: String,
        unique: true,
        trim: true,
        required: true,
        lowercase: true
    },
hashed_password: {
        type: String,
        required: true
    },
    initials: String
});

userSchema.virtual('password')
    .set(function(password) {
            this._password = password;
            this.salt = this.makeSalt();
            this.hashed_password = this.encryptPassword(password);
    })
    .get(function() {
            return this._password;
    }
);



const studentSchema = extend(userSchema, {
    teachers: []   
});

const teacherSchema = extend(userSchema, {
    isActiveTutor: {
        type: Boolean,
        default: false
    }
})
  


const User =  mongoose.model('User', userSchema);
const Student = mongoose.model('Student', studentSchema);
const Teacher = mongoose.model('Teacher', teacherSchema);

module.exports = {
    User,
    Student,
    Teacher
}

【问题讨论】：

标签： javascript node.js mongodb mongoose mongoose-schema

【解决方案1】：

您正在使用mongoose-extend-schema NPM，这只会将对象从源架构合并到新架构，像这样，

function extendSchema (Schema, definition, options) {
  return new mongoose.Schema(
    Object.assign({}, Schema.obj, definition),
    options
  );
}

mongoose 中有一个名为clone() 的新方法，它返回模式的深层副本，以及一个add()，将键路径/模式类型对添加到此模式，您还可以add() 另一个模式和复制所有路径、虚拟变量、getter、setter、索引、方法和静态变量。

我描述了两种方法，你可以使用这两种方法中的任何人，

1) 克隆父架构并向其添加新属性

// Skipping your 1) User Schema and 2) Virtual Function, because its remain same

const studentSchema = userSchema.clone();
studentSchema.add({
    teachers: []
});

const teacherSchema = userSchema.clone();
teacherSchema.add({
    isActiveTutor: {
        type: Boolean,
        default: false
    }
});

const User = mongoose.model('User', userSchema);
const Student = mongoose.model('Student', studentSchema);
const Teacher = mongoose.model('Teacher', teacherSchema);

module.exports = { User, Student, Teacher }

2) 创建新架构并向其添加父架构

// Skipping your 1) User Schema and 2) Virtual Function, because its remain same

const studentSchema = new Schema({
    teachers: []
}).add(userSchema);

const teacherSchema = new Schema({
    isActiveTutor: {
        type: Boolean,
        default: false
    }
}).add(userSchema);

const User = mongoose.model('User', userSchema);
const Student = mongoose.model('Student', studentSchema);
const Teacher = mongoose.model('Teacher', teacherSchema);

module.exports = { User, Student, Teacher }

【讨论】：