file upload - Rails 5.2 Active Storage purging/deleting attachments

Question

So I'm using Active Storage to upload multiple images attached to a Collection model. Everything works well except whenever I'm trying to purge/delete a single attachment from a collection.

The problem: For some reason all my images immediately get purged/deleted whenever I load the show page of a collection. Of course I only want to delete a file whenever I click the link. Does anyone know how to solve this problem?

My collection show view:

<div id="gallery">
  <% @collection.images.each do |image| %>
    <%= image_tag(image) %>
    <%= link_to 'Remove image', image.purge %>
  <% end %>
</div>

I've read documentation on http://edgeguides.rubyonrails.org/active_storage_overview.html#removing-files (see paragraph 4)

but sadly this doesn't give any information on how to specifically use the purge or purge_later method.

EDIT Currently changed my code to this (which still sadly doesn't work):

<div id="gallery">
  <% @collection.images.each do |image| %>
    <%= image_tag(image) %>
    <%= link_to 'Remove', delete_image_attachment_collections_url(image.signed_id),
                method: :delete,
                data: { confirm: 'Are you sure?' } %>
    <% end %>
</div>

With this in my collections_controller.rb

  def delete_image_attachment
    @image = ActiveStorage::Blob.find_signed(params[:id])
    @image.purge
    redirect_to root_path
  end

Which is giving me this error after I tried to delete an attached image:

Server log:

Started DELETE "/collections/eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBYdz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--3e75276d414b4c2040e02cf0afbc083e2337faa0/delete_image_attachment" for ::1 at 2018-03-29 19:06:55 +0200
Processing by CollectionsController#delete_image_attachment as HTML
  Parameters: {"authenticity_token"=>"60zIkeknxRYp/sJIWNwF+BrEftYHSCQvak34h8FkadPXgVPQSXN/sCoxI/6FU+jZbqQitES81fyqkmIx6XYp6w==", "id"=>"eyJfcmFpbHMiOnsibWVzc2FnZSI6IkJBaHBYdz09IiwiZXhwIjpudWxsLCJwdXIiOiJibG9iX2lkIn19--3e75276d414b4c2040e02cf0afbc083e2337faa0"}
  ActiveStorage::Blob Load (0.1ms)  SELECT  "active_storage_blobs".* FROM "active_storage_blobs" WHERE "active_storage_blobs"."id" = $1 LIMIT $2  [["id", 90], ["LIMIT", 1]]
  ? app/controllers/collections_controller.rb:69
  Disk Storage (0.1ms) Deleted file from key: 8wpzqPQcWYjK2rVEejcU88FB
  Disk Storage (0.0ms) Deleted files by key prefix: variants/8wpzqPQcWYjK2rVEejcU88FB/
   (0.0ms)  BEGIN
  ? app/controllers/collections_controller.rb:70
  ActiveStorage::Blob Destroy (0.2ms)  DELETE FROM "active_storage_blobs" WHERE "active_storage_blobs"."id" = $1  [["id", 90]]
  ? app/controllers/collections_controller.rb:70
   (2.0ms)  COMMIT
  ? app/controllers/collections_controller.rb:70
  ActiveStorage::Attachment Load (0.2ms)  SELECT  "active_storage_attachments".* FROM "active_storage_attachments" WHERE "active_storage_attachments"."record_id" = $1 AND "active_storage_attachments"."record_type" = $2 AND "active_storage_attachments"."name" = $3 LIMIT $4  [["record_id", 90], ["record_type", "ActiveStorage::Blob"], ["name", "preview_image"], ["LIMIT", 1]]
  ? app/controllers/collections_controller.rb:70
Redirected to http://localhost:3000/
Completed 302 Found in 5ms (ActiveRecord: 2.5ms)

Output of rake routes:

                            Prefix Verb   URI Pattern                                                                              Controller#Action
                              root GET    /                                                                                        home#index
                             about GET    /about(.:format)                                                                         pages#about
                           contact GET    /contact(.:format)                                                                       pages#contact
                          settings GET    /settings(.:format)                                                                  settings#edit
                       new_setting GET    /setting/new(.:format)                                                                   settings#new
                      edit_setting GET    /setting/edit(.:format)                                                                  settings#edit
                           setting GET    /setting(.:format)                                                                       settings#show
                                   PATCH  /setting(.:format)                                                                       settings#update
                                   PUT    /setting(.:format)                                                                       settings#update
                                   DELETE /setting(.:format)                                                                       settings#destroy
                                   POST   /setting(.:format)                                                                       settings#create
delete_image_attachment_collection DELETE /collections/:id/delete_image_attachment(.:format)                                       collections#delete_image_attachment
                       collections GET    /collections(.:format)                                                                   collections#index
                                   POST   /collections(.:format)                                                                   collections#create
                    new_collection GET    /collections/new(.:format)                                                               collections#new
                   edit_collection GET    /collections/:id/edit(.:format)                                                          collections#edit
                        collection GET    /collections/:id(.:format)                                                               collections#show
                                   PATCH  /collections/:id(.:format)                                                               collections#update
                                   PUT    /collections/:id(.:format)                                                               collections#update
                                   DELETE /collections/:id(.:format)                                                               collections#destroy
                rails_service_blob GET    /rails/active_storage/blobs/:signed_id/*filename(.:format)                               active_storage/blobs#show
         rails_blob_representation GET    /rails/active_storage/representations/:signed_blob_id/:variation_key/*filename(.:format) active_storage/representations#show
                rails_disk_service GET    /rails/active_storage/disk/:encoded_key/*filename(.:format)                              active_storage/disk#show
         update_rails_disk_service PUT    /rails/active_storage/disk/:encoded_token(.:format)                                      active_storage/disk#update
              rails_direct_uploads POST   /rails/active_storage/direct_uploads(.:format)                                           active_storage/direct_uploads#create

My routes.rb:

Rails.application.routes.draw do
  root 'home#index'

  get 'about', to: 'pages#about', as: :about
  get 'contact', to: 'pages#contact', as: :contact
  get 'instellingen', to: 'settings#edit'

  resource :setting
  resources :collections do
    member do
      delete :delete_image_attachment
    end
  end
end

Answer 1

You are looping through the collection of images and calling the purge method on each one. Instead you should be linking to a destroy method on your controller, something like the below taking into account your controller actions and guessing at your route names.

The error is because image object returns its full path and the link thinks that what you want to point to. Instead you just want its signed_id and want the link to call the route that has your delete_image_attachment path.

 <%= link_to 'Remove', delete_image_attachment_collections_url(image.signed_id),
                method: :delete,
                data: { confirm: 'Are you sure?' } %>

The destroy method would look something like this...

def delete_image_attachment
  @image = ActiveStorage::Blob.find_signed(params[:id])
  @image.purge
  redirect_to collections_url
end

The route should be something like so...

resources :collections do
  member do
    delete :delete_image_attachment
  end
end

Check out the rails routing guide for more fun routing facts.