Node.js — mongoose static method example

Question

I wish to define a method on a model UserModel such that I get the names of all the users that have userId < 10.

Following is my implementation:

// pseudo code
UserModel === {
    userId : Number,
    userName: String
}

UserSchema.statics.getUsersWithIdLessThan10 = function(){
    var usersLessThan10 = []
    this.find({userId : {$lt : 10}}, function(error, users){
        users.forEach(function(user){
            console.log(user.userName) // ... works fine
            usersLessThan10.push(user.userName)
        })
    })
    return usersLessThan10
}

I understand why this doesn't seem to work — async find API. But if that's the case, then whats the way to do it? This async stuff is kind of overwhelming.

Answer 1

Add callback and return the users in this callback as follows:

UserSchema.statics.getUsersWithIdLessThan10 = function(err, callback) {
    var usersLessThan10 = []
    this.find({userId : {$lt : 10}}, function(error, users){
        users.forEach(function(user){
            console.log(user.userName) // ... works fine
            usersLessThan10.push(user.userName)
        })
        callback(error, usersLessThan10)
    })
}

Then call usersLessThan10 with the callback:

... .usersLessThan10(function (err, users) {
    if (err) {
        // handle error
        return;
    }
    console.log(users);
})