Provide key for file upload

[rctneil]

Allow a way for a key to be passed in for a file as per the key option described here: https://edgeguides.rubyonrails.org/active_storage_overview.html#attaching-file-io-objects

Is there a possible workaround for being able to specify the name of uploads for when they are stored at the source?

[adrianthedev]

I don't quite get the request. Can you please rephrase it or maybe make a screen recording or something?

[rctneil]

Ok, sorry. Let me try to explain my need.

I am building an extension to my app which requires one or more images uploading to each record. I have a spreadsheet of the records to be added. I also need to be able to cross reference the files that are uploaded directly from where they are stored, eg, the Amazon S3 bucket with the lines in my spreadsheet just by looking at the filenames being able to tell which record in my spreadsheet they belong to.

It looks like Active Storage provides a "key" option. When creating a file upload field type in Avo, it would be nice if there were 3 options:

1. Auto generated key (default (exactly as it works now))
2. A method on the model that provides a key name to use (maybe by joining the the "name" field with a random id or something) Whatever the user wants really.
3. A text field that the user can type into specify the name (obviously with the user knowing that if an existing key is chosen then the file will get overwirtten).

Does that make more sense?

[adrianthedev]

It looks like Active Storage provides a "key" option.

Where is that option named key? I can't find it in the docs.

[rctneil]

The link has this snippet in it:

`There is an additional parameter key that can be used to specify folders/sub-folders in your S3 Bucket. AWS S3 otherwise uses a random key to name your files. This approach is helpful if you want to organize your S3 Bucket files better.

@message.images.attach(
io: File.open('/path/to/file'),
filename: 'file.pdf',
content_type: 'application/pdf',
key: "#{Rails.env}/blog_content/intuitive_filename.pdf",
identify: false
)
COPY
This way the file will get saved in the folder [S3_BUCKET]/development/blog_content/ when you test this from your development environment. Note that if you use the key parameter, you have to ensure the key to be unique for the upload to go through. It is recommended to append the filename with a unique random key, something like:

def s3_file_key
"#{Rails.env}/blog_content/intuitive_filename-#{SecureRandom.uuid}.pdf"
end
COPY
@message.images.attach(
io: File.open('/path/to/file'),
filename: 'file.pdf',
content_type: 'application/pdf',
key: s3_file_key,
identify: false
)`

From this guide: https://edgeguides.rubyonrails.org/active_storage_overview.html#attaching-file-io-objects

[adrianthedev]

Oh right, I missed it, the first time.

We can't tackle this right now.
It shouldn't be very difficult to add. Would you like to give it a try?

Approach

Here is what you suggested and how we could implement it.

Add the key option to the fields

• Update the file and files fields here and here to add another option named key
• Provide that key in all places where we use the attach method. In the attachments controller (here) and in the fill_field method here
• To do that in the controller, we might need to identify the field from the resource in order to get the key off of it.

# pseudo-code to do that
file_field = @resource.get_field params[:attachment_key]
file_field.key

The API we are shooting for is this:

field :spreadsheet, as: :files, key: SOME_KEY

The SOME_KEY value will be forwarded through the key option all the way to the attach invocation.

[rctneil]

Yes, i'm just taking a look at it now.

Quick question:
Are we taking the approach here that key: SOME_KEY will point to a method on the model?

[adrianthedev]

We could make that dynamic using the ExecutionContext. Here's a PR that makes an option callable so you know how to do it.

So we'd have two APIs:

# static
field :spreadsheet, as: :files, key: SOME_KEY

# dynamic
field :spreadsheet, as: :files, key: -> { record.some_method }

[rctneil]

@adrianthedev

I'm wondering if you can help point me in the right direction with this. I'm trying to figure out in my head the flow through the application.

I'm assuming on an update, the route post "/resources/:resource_name/:id/attachments/", to: "attachments#create" within the avo_api scope is called?

If so, then in the attachments_controller I see:

      if association_name
        @record.send(association_name).attach(blob)

Just to ensure I see changes, I added a prints line just before that but I do not see any output in my console. I also tried commenting out that attach statement and it still worked fine.

This is making me believe that this is not the .attach method being used.

Am I missing it with it being elsewhere? I'm just struggling as nothing i'm doing seems to have any effect?

Thanks

[adrianthedev]

That is the method used for direct_uploads AFAIK.

I think you're looking for this one.

[rctneil]

Ok, Thanks. I did see that but ignored it as I thought that was just for the multi-file field and not the single file field.

I'll take another look and keep you updated.

Thanks for the pointer.

[rctneil]

@adrianthedev I'm really sorry, but i'm struggling here. I'm not sure i'm understanding the flow of how Avo is working.

I had the understand that file_field was for a single file upload, and files_field was for multiple files. eg (has_one_attached and has_many_attached)?

If so, then i'm unsure as to why, when I temporarily comment out the .attach is the attachments_controller (or the files_field) as you suggested above, does the attachment functionality still work flawlessly.

I sooo want this to work but really not understanding how it fits together.

[adrianthedev]

I mentioned in my last message that the attach method from the attachemnts controller is used for direct uploads (please read the docs).

If your field does not use the direct_upload option, it will use the fill_field method that I pointed out.
That's what you should be referring to.