Creating an array of key-value pairs(fetched from a mongoDB database) dynamically

[Aryak Sengupta]

I am trying to create an array of Key-Value pairs dynamically with a document from a MongoDB database .

I have posted my question on Stack Overflow but still I can't figure out where I am going wrong. This is my question ->
 
Creating an array of key-value pairs(fetched from a mongoDB database) dynamically

Any help will be appreciated, 
Thank You. 

[Angel Java Lopez]

Hi!

I didn't run this code, but maybe is a solution

router.get('/account',isAuthenticated, function(req,res){

   var following_users_details = [];

   var i = 0;

   

   getOneUser();

   

   function getOneUser() {

   

        var following_user = req.user.following_users[i++];

        

        if (!following_user) {

            res.render('users/userAccount',{user:req.user, following_users_details:following_users_details });

            return;

        }

        

        User.findOne({'username' : following_user },

            function(err,user)

            {

                if (!err) 

                    following_users_details.push({

                        username: user.username,

                        profilepic : user.photo,

                        userbio : user.bio

                    });

                    

                setTimeout(getOneUser, 0);

            });

    }

});

The original code returned a result BEFORE the find one user executes the callback.

The above code retrieves one user, and then, in the callback, invoke the same function to retrieve another user. It should be better solutions, but I hope this code works.

Understanding callbacks/async is the price to pay to live at Node.js paradise ;-)

Angel "Java" Lopez

@ajlopez

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[Aryak Sengupta]

Hi Angel,  

Thanks for your reply.I resolved it. What you mentioned in the end is absolutely true. 

"Understanding callbacks/async is the price to pay to live at Node.js paradise ;-"

I want to dive in deeper to async callbacks. Can you refer me some resources which will help me to grasp the concept properly. 

Thanks again. 

To view this discussion on the web visit https://groups.google.com/d/msgid/nodejs/CAMs%2BDqK0HCDGPPwt7G4mGXjdtnrRGyhqooQC6P2FhGvMD3YFew%40mail.gmail.com.

[zladuric]

Your query is also not optimal.

As I wrote on your SO question, you should do something like this:

    User.find({

        // setup query

        username: {$in: req.user.followed_users}

    },

    {
        // setup fields to return

        username: true,

        profilepic: true,

        userbio: true

      },

      // callback

      function (err, followedUsers) {

        res.json(followedUsers); // or render or whatever.

      });

  },

[Aryak Sengupta]

That is exactly what I did to resolve it. Thanks for your reply. 

To view this discussion on the web visit https://groups.google.com/d/msgid/nodejs/ed412464-5391-4470-9710-5a695b4b0312%40googlegroups.com.