How to store files with meta data in LoopBack?

Question

What I want to do: Have an html form, with a file input inside. When a file is chosen, the file input should upload the file, and get a file id, so when the form is submitte

Answer 1

Depending on your scenario, it may be worth looking at utilising signatures or similar allowing direct uploads to Amazon S3, TransloadIT (for image processing) or similar services.

Our first decision with this concept was that, as we are using GraphQL, we wanted to avoid multipart form uploads via GraphQL which in turn would need to transfer to our Loopback services behind it. Additionally we wanted to keep these servers efficient without potentially tying up resources with (large) uploads and associated file validation and processing.

Your workflow might look something like this:

1. Create database record
2. Return record ID and file upload signature data (includes S3 bucket or TransloadIT endpoint, plus any auth tokens)
3. Client uploads to endpoint

For cases where doing things like banner or avatar uploads, step 1 already exists so we skip that step.

Additionally you can then add SNS or SQS notifications to your S3 buckets to confirm in your database that the relevant object now has a file attached - effectively Step 4.

This is a multi-step process but can work well removing the need to handle file uploads within your core API. So far this is working well from our initial implementation (early days in this project) for things like user avatars and attaching PDFs to a record.

Example references:

http://docs.aws.amazon.com/AmazonS3/latest/dev/UsingHTTPPOST.html

https://transloadit.com/docs/#authentication