Return file from GraphQL resolve

Question

I am currently working on an application with the current tech stack:

Backend:

• Mongoose

• Express

• Apollo

• GraphQL

Frontend:

• Vuejs

• Apollo

• GraphQL

I have succeeded in uploading files to the server using GraphQL, what I am stuck with is how to implement the 'download' feature. With a normal RESTApi endpoint I can use res.download(filePath) and it works. How do I do this with GraphQL since I don't want to use REST.

Or is there any other standard to go by in this scenario?

Thanks!

Answer 1

GraphQL uses JSON format, which represents as text format, not as binary.

If you don't want download files with REST, then you should:

1. Encode your file content into base64 string in the back end. Related question
2. Send this string as part of query response.
3. Save encoded base64 string as a file in the front end. Related question

But right architecture design is add a file link in the GraphQL response and use browser for downloading/rendering the file.

Answer 2

It's better to send a hashed & temporary link to download it

1. Save the file and hash the name on your static server (to limit access to other users)
2. The file should be temporary and should expire in a short time
3. Send the link of the file in response to API