这个Mongoose独特的预保存验证在做错什么? [英] What am I doing wrong in this Mongoose unique pre-save validation?

问题描述

我正在尝试创建一个具有唯一用户名的用户模型.这是它的代码:

I'm trying to create a User model, that has an unique username. Here's the code for it:

var mongoose = require("mongoose");

var Schema = mongoose.Schema;

var UserSchema = new Schema({
    username: String,
    password: String,
});

UserSchema.virtual("password_confirmation").get(function() {
    return this.pw_conf;
}).set(function(value) {
    this.pw_conf = value;
});

UserSchema.path("username").required(true);
UserSchema.path("password").required(true);

UserSchema.pre("save",function(next, done) {
    var self = this;
    mongoose.models["User"].findOne({username : self.username},function(err, user) {
        if(user) {
            self.invalidate("user","username must be unique");
        }
        done();
    });
    next();
});

UserSchema.pre("save",function(next) {
    if(this.pw_conf !== this.password) {
        next(new Error("Must specify the password confirmation"));
    }
    else {
        next();
    }
});

module.exports = mongoose.model("User",UserSchema);

我也在测试唯一性是否有效:

I was also testing to see if the uniqueness works:

var User = require("./users"),
  mongoose = require("mongoose");
var u = new User();

mongoose.connect('mongodb://localhost/my_database');

u.username = "me";
u.password = "password";
u.password_confirmation = "password";
u.save(function(err) {
    if(err) {
        console.log(err);
    }
    mongoose.disconnect();
});

问题是，不是.每次运行代码时，都会创建一个新对象.我知道，可能还有其他方法可以确保唯一性，但是我想以这种方式做到这一点.处理findOne方法的结果后，是否应该不调用done?我打错电话next吗?

Problem is, it doesn't. Each time I run the code, I get a new object created. I am aware that there are probably other ways of ensuring uniqueness, but I'd like to do it in this way. Shouldn't I be calling done after I handle the result of the findOne method? Am I calling next wrong?

推荐答案

要使用并行中间件(带有next和done参数)，您需要将true作为第二个参数传递.

To use parallel middleware (with next and done parameters), you need to pass true as the second parameter.

除此之外，还有两种可能性:

Beyond that, there are two possibilities:

您的self.invalidate调用应该引用"username"而不是"user".如果仍不能解决问题，如果要中止保存操作，可以通过将Error对象传递给done来明确地使事情失败:

Your self.invalidate call should be referencing "username" instead of "user". If that doesn't fix it, you can fail things explicitly by passing an Error object to done if you want to abort the save operation:

UserSchema.pre("save", true, function(next, done) {
    var self = this;
    mongoose.models["User"].findOne({username: self.username}, function(err, user) {
        if(err) {
            done(err);
        } else if(user) {
            self.invalidate("username", "username must be unique");
            done(new Error("username must be unique"));
        } else {
            done();
        }
    });
    next();
});

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