How to query for records where Active Storage attached and image is variable?

Question

How can I query for all the users who have an image attached and where the image is .variable??

e.g

I can do this

# controller

@users = User.all

view:

<% if user.image.attached? && user.image.variable? %>
<!-- display image -->
<% end %> 

Rather than having that logic in the view, I wonder if I can simply query for only those @users which meet the conditions of both user.image.attached? and user.image.variable?

Is this possible with some Active Record query?

Answer 1

Active Storage doesn't provide shortcut scopes for what you want, but you can come up with a custom solution.

For fetching only users with an attached image, join the corresponding attachments:

User.joins(:image_attachment)

An attachment (or rather: a blob) is variable, if its content_type is present in the ActiveStorage.variable_content_types array, see https://github.com/rails/rails/blob/v6.1.3.2/activestorage/app/models/active_storage/blob/representable.rb#L42-L44.

So we can further query for that content_type, but we need to join the blob (implicitly through the attachment) for that:

User.joins(:image_blob).where(active_storage_blobs: {content_type: ActiveStorage.variable_content_types})

And that should be the query for what you want. Additionally, you can have that as a scope so it's shorter when used:

# app/models/user.rb

scope :with_variable_image -> do
  joins(:image_blob).where(active_storage_blobs: {content_type: ActiveStorage.variable_content_types})
end

# app/controllers/users_controller.rb or wherever

users = User.with_variable_image