Implement follow/unfollow in Node.js

Question

I am a beginner and i want to create follow/unfollow functionality in my app.

router.put('/user/:id/follow', auth.verifyuser, (req, res)=>{

user.findById(req.params.id)
.then((otherUser)=>{
    if(otherUser.followers.includes(req.userInfo._id)){
       
        return res.json({message: "Already following user"});
    }
    req.userInfo.updateOne({$push: {followings: req.params.id}});
    otherUser.updateOne({ $push: {followers: req.userInfo._id}});
    res.json({message: "following user"});
    console.log(otherUser.followers);

})
.catch((e)=>{
    res.json(e);
})})

when running the code it recieves the message "following user" but dosen't add to the database i.e. Mongodb (i'm using MERN stack)

It seems like this block of code is not executing.

req.userInfo.updateOne({$push: {followings: req.params.id}});
otherUser.updateOne({ $push: {followers: req.userInfo._id}});

what am i doing wrong here?

score 0 · Answer 1 · answered Feb 10 '22 at 18:33

0

I think that is because req.userInfo and otherUser is an immutable mongo object. try this instead (assuming "user" is your model object):

user.updateOne(
   { _id:  req.userInfo._id},
   {$push: {followings: req.params.id}
)

  user.updateOne(
       { _id:  otherUser._id},
       { $push: {followers: req.userInfo._id}}
    )

note: while comparing _id please check if you are storing as objectId or string.

for your reference: Comparing mongoose _id and strings

answered Feb 10 '22 at 18:33

Shawon Kanji

710
5
13

it seems to work only when it is followed by .then() method. or it skips to `res.json({message: "following user"});` – Bhupendra Pandey Feb 11 '22 at 07:04

score 0 · Answer 2 · answered Feb 11 '22 at 08:47

Well, this seems to work

router.put('/user/:id/follow', auth.verifyuser, (req, res)=>{

user.findById(req.params.id)
.then((otherUser)=>{
    if(!otherUser.followers.includes(req.userInfo._id)){
        Promise.all([
            user.updateOne({_id:req.userInfo._id}, {$push: {followings: req.params.id}}),
            user.updateOne({_id: otherUser._id},{$push: {followers: req.userInfo._id}})
        ]).then(()=>{
            res.json({message: "following user"});
        })
        .catch((e)=>{
            res.json(e);
        }); 
    }else{
        return res.json({message: "Already following user"});
    }
})
});

But it would be better if someone explained what went wrong previously, as I said i am beginner and would appreciate the feedback.

Implement follow/unfollow in Node.js

2 Answers2