Node.js — mongoose static method example - node.js

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);
})

Answer 2

try this:
API code:
var UserApi = require('./UserSchema');
var callback = function(response){
console.log(response); // or res.send(200,response);
}
UserApi.getUsersWithIdLessThan10(callback);
UserSchema code:
UserSchema.getUsersWithIdLessThan10 = function(callback){
var usersLessThan10 = []
this.find({userId : {$lt : 10}}, function(error, users){
if (error)
{ callback(error)}
else{
users.forEach(function(user){
console.log(user.userName) // ... works fine
usersLessThan10.push(user.userName);
//TODO: check here if it's the last iteration
callback(usersLessThan10);
})
}
})
}