CODEWITHSUNDEEP
mongodbmongoose
Fizzix
Fizzix

Reputation: 24405

Setting a value post update with the `findOneAndUpdate` Mongoose hook

I am trying to use the findOneAndUpdate hook with Mongoose (discussed in detail here), although I'm having some problems trying to set a value post update.

For example:

MySchema.findOneAndUpdate({_id: fj394hri3hfj}, {$push: {comments: myNewComment}})

Will trigger the following hook:

MySchema.post('findOneAndUpdate', function(result) {
    this.update({}, { totalNumberOfComments: result.comments.length });
});

Although, the hook will $push to comments the myNewComment again, therefore making a duplicate entry.

I use this.update({}, {....}) instead of this.findOneAndUpdate({}, {....}) within the hook so that the post hook is not called infinitely.

The totalNumberOfComments is set perfectly to the length of comments.length.

So it seems as if this.update({}, {....}) is just pushing more update fields to the already existing update fields on this.

How can I just set totalNumberOfComments within my hook instead of re-pushing to comments again?

Upvotes: 1

Views: 3583

Answers (1)

Raeesaa
Raeesaa

Reputation: 3316

The issue seems to be in update query you wrote in post findOneAndUpdate hook. Try replacing it with,

MySchema.post('findOneAndUpdate', function(result) {
    this.totalNumberOfComments = this.result.comments.length;
    this.save(function(err) {
       if(!err) {
          console.log("Document Updated");
       }
    });
});

And hopefully it should work.

I would also suggest, using find and save for updating document instead of findOneAndUpdate and its post hook.

Edit:

In case you need to use find and save, you can replace above code with:

MySchema.findById(fj394hri3hfj, function(err, doc){

    doc.comments.push(myNewComment);
    doc.totalNumberOfComments += 1;
    doc.save(function(err){

       console.log("Document Updated");       
    }); 
});

and it should work.

Upvotes: 5

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