ObjectId in must be a single string of 12 bytes or a string of 24 hex characters on reloading the product page

Hey there everyone,
I was following the jumpstart ecommerce tutorial with mongo db, and I encountered this problem.

When I click on the card and go to the product page it works fine, but when i reload the product page it returns an error:`Error: ObjectId in must be a single string of 12 bytes or a string of 24 hex characters

The realm function for getting the product:

exports = function(arg){

    let collection = context.services.get("mongodb-atlas").db("store").collection("products");

  return collection.findOne({_id:BSON.ObjectId(arg)})};

Thank you for taking your time out to read this question.

Jumpstart https://www.youtube.com/playlist?list=PL4RCxklHWZ9v2lcat4oEVGQhZg6r4IQGV
Screen Recording of the issue: https://drive.google.com/file/d/12zWMujEl-gb4VyD0zq5uOvMYKeZ_8keu/view?usp=sharing

Vaarun Sinha

1 Like

Did you find a resolution? Anyone from Mongo can chime in?

I’m having the same type of issue. But im trying something like this in an API:

const value = JSON.stringify(uid)
const palette = await db.collection("users").find({ _id: ObjectId(value) }).toArray()
1 Like

when you reload, your page has only what you include in your URL and the things you have saved in the Browser’s cache.

In both cases, if you do not properly code what properties will be available to the page and how the page handles them are both left to the developer of the frontend.

In your case, it is clear that the page does not do that inside the products page, but relies on the product card to pass the id to it. since the id is not in the form MongoDB expects (most possibly it is just null or undefined) then you get that error.

Your issue has the same error for a different reason. JSON.stringify() will give an error if its arguments is not an object. You don’t seem to get an error in that step so uid is an object, and your value will be something like this:


see, the single quotes are surrounding those inner double quotes. you can now see why ObjectId() gave an error. value does not have a proper shape.

you have two options now depending on what uid holds.

const value = uid.id // directly use the id field if it is a proper formatted string
.....find( { _id : uid.id } ) // directly use the id field if it is a proper object id.

I’m still battling this issue. There’s something happening when the document _id is sent from the client to the server. It’s no longer being read as a string even though its typeof value equals string.

alright, does everyone here know we have a “console.log” function to print things before/after some statements?

I know I forgot to request this at the time I gave answers, but can you please first print out the data you are about to send to the server and then print out what the server gets?

The problem you guys are having might be caused by many things, but it all seems to come down to this: either sending or receiving side does it wrong. please check these first:

  • frontend: do you have proper 12/24 char id? print it out to see if you are correct.
  • frontend: do you use JSON.stringify before sending your request? you need this if you are sending an object like {id:"some_prod_id"}
  • frontend: make sure to set content type if you send JSON.
  • backend: what do you get in your request object? print it out. check the logs.
  • backend: make sure you are accepting the same content type.
  • backend: do you use a JSON parser? if you have sent a JSON content, you need to parse it before going further. print out the id you get. check the logs.
  • backend: you might need to convert from string to ObjectId, either by function or {id:{$oid:"some_prod_id"}}