创建两个模型时对sailsjs的错误处理

Question

I'm pretty new two nodejs and sails. I'm trying to create two models inside one action. My question is how to handle the errors which can occur in both queries.

Current Code:

new: function (req, res) {
    var errorArray = [];
    var data = req.allParams();

        User.create({
            username: data.username,
            password: data.password,
            device_id: data.device_id,
            own_number: data.own_number,
            mobile_numbers: data.mobile_numbers
        }).exec(function (err, user) {
            if(err){
            errorArray.push(err);
            }
        });

        Mobile_number.create({
          number: data.own_number,
          number_id: this.hash(data.own_number)
        }).exec(function(err, mobile_number){
          sails.log(err);
          if(err){
            errorArray.push(err);
          }
       });

       if(errorArray.length == 0){
         return res.ok('success');
       }else {
        return res.send(errorArray.toString());
       }    
  }

The problem with this code is that the if at the end is handled before the queries finish. What would be the right way for to wait for the queries?

Bruno

Answer 1

First of all your code will not work because node.js is asynchronous. So you check if there are errors before functions are executed. Below are 2 solutions:

You can use async.series . If you use that it will stop executing if first method fails and it will return it's error. It it succeed it will go to second method.

async.series([
        function(callback) {
            User.create({
                username: data.username,
                password: data.password,
                device_id: data.device_id,
                own_number: data.own_number,
                mobile_numbers: data.mobile_numbers
            }).exec(callback);
        },
        function(callback) {
            Mobile_number.create({
                number: data.own_number,
                number_id: this.hash(data.own_number)
            }).exec(callback);
        }
    ],
    function(error, results) {
        // error first finished 
        if(error)
            res.send('error');
        else
            res.send('success');
    }
);

Or you can do it traditional way with callbacks.

new: function(req, res) {
    var errorArray = [];
    var data = req.allParams();

    var mobileCreateCallback = function(err, mobile_number, user) {
        sails.log(err);
        if (err) {
            errorArray.push(err);
        }

        if (errorArray.length === 0) {
            sails.log(user, mobile_number);
            return res.ok('success');
        } else {
            return res.send(errorArray.toString());
        }
    };

    var userCreateCallback = function(err, user) {
        if (err) {
            errorArray.push(err);
        }

        Mobile_number.create({
            number: data.own_number,
            number_id: this.hash(data.own_number)
        }).exec(function(error, mobile_number) {
            mobileCreateCallback(error, mobile_number, user);
        });
    };

    User.create({
        username: data.username,
        password: data.password,
        device_id: data.device_id,
        own_number: data.own_number,
        mobile_numbers: data.mobile_numbers
    }).exec(userCreateCallback);
}

You should reed about callbacks: callbackhell and asynchronous functions in node.js/sails.js.