File extension for derivations generated with derviation endpoint?

[evenreven]

First, thank you for this amazing gem, I recommend it to anyone who wants something better than activestorage! <3

This may be a really dumb question, but I've read the docs and can't find an easy way to do this. I want the derivations to always have a file extension. Mime type is working correctly in the browser, so my setup is otherwise correct.

The file name in my uploads directory is 9af29b0592e6e95b4b96beee1da07309.jpg

The file name of the processed derivative is thumb-eyJyZXNpemVfdG9fZml0IjpbMzkyLDM5Ml0sImNvbnZlcnQiOiJhdmlmIiwic2F2ZXIiOnsicXVhbGl0eSI6ODV9fQ

I want it to be thumb-eyJyZXNpemVfdG9fZml0IjpbMzkyLDM5Ml0sImNvbnZlcnQiOiJhdmlmIiwic2F2ZXIiOnsicXVhbGl0eSI6ODV9fQ.avif

How would I do this?

[janko]

First, thank you for this amazing gem, I recommend it to anyone who wants something better than activestorage! <3

You're welcome, glad it's working out for you ❤️

How would I do this?

This isn't supported yet. Is #747 what you had in mind?

[evenreven]

Wow, that was fast! Looks like exactly what I had in mind. I'll play with it tomorrow.

Would it work to pass Shrine.urlsafe_serialize(transformations) as an argument to file.derivation_url, or do I need to be explicit? I'm setting the Vips options from the view itself (or technically I use an abstract Phlex component for all images and do it there) , but I could quite easily rewrite the component to pass regular width/height/crop arguments and assemble the Vips method call in the uploader class if I need to.

[janko]

Ideally you wouldn't need to call Shrine.urlsafe_serialize(transformations), as that's considered internal API. The transformations are defined under a derivation key, and you just generate the URL with that key + extension.

[evenreven]

Oops, I didn't know this! 🫣 I adapted it from this example: https://shrinerb.com/docs/processing#dynamic-derivation.

I changed my convenience method now to this and it seems to work very well! Thank you!

My full code:

# app/components/base.rb (phlex component)
class Components::Base < Phlex::HTML
  # ...
  def derivation_url(file, quality:, width:, height:, crop:, format:)
    file.derivation_url(:thumb, quality, width, height, crop, format, extension: format.to_s)
  end
end

...and my uploader class to this:

class ImageUploader < Shrine
  derivation :thumb do |original, quality, width, height, crop, format|
    if crop == true
      ImageProcessing::Vips
        .source(original)
        .convert(format.to_s)
        .saver(quality: quality.to_i)
        .resize_to_fill!(width.to_i, height.to_i)
    else
      ImageProcessing::Vips
        .source(original)
        .convert(format.to_s)
        .saver(quality: quality.to_i)
        .resize_to_fit!(width.to_i, height.to_i)
    end
  end
end

Then:

derivation_url(@photo.image, crop: false, width: 300, height: 200, format: :avif, quality: 85)

...from the view.

Probably ways to make the upload class more DRY but it's explicit and easy to grok, which is important to me.

[janko]

Actually, I think I misunderstood. You're not talking about the extension in derivation URL, you're talking about the extension of the uploaded file on storage, correct? Or the download filename?

[evenreven]

No, you didn't misunderstand, I absolutely was talking about the extension in the derivation URL, and the PR works very well and solved my problem. :)

[janko]

Ah, thanks for confirming, I merged the PR now and renamed the option to :format.