Active Storage: How to create "named variants" that are cropped by user-supplied coordinates

rubyonrails-talk
1

The idea of named variants (merged pull request) is to be able to define image variants (i.e. different sizes) in 1 place (in the Model), instead of redundantly and all over your Views.

But, if you’re in a situation in which you need to…

  1. Keep the uploaded original image unchanged, and
  2. Crop the image (based on coordinates supplied by the user), to then:
  3. Create several variants (based on the cropped version)

… I believe that this would be impossible in the current version of “named variants”, an example of which looks like this:

class User < ApplicationRecord

  has_one_attached :avatar do |attachable|
    attachable.variant :large,  resize_to_limit: [300, nil]
    attachable.variant :medium, resize_to_limit: [100, nil]
    attachable.variant :small,  resize_to_limit: [ 50, nil]
  end

end

Or am I missing something?

Would this be an idea for an update to the Rails core?

2

How I’ve done this type of thing with dragonfly (similar to active storage) is you store the user’s crop coordinates/dimentions as a json object or string. Then use that in the views image helper based on current_user or whatever. Your example can only handle predefined options from the looks of it