Bear with me, I am new to posting and Rails so sorry if I mess up phrasing!!

I am working on a Rails app with many similar models. Each view has a _form.html.haml partial that differs in content but contains similar components, such as buttons to submit, delete, etc. Every model has_many_attached photos, and in the form you can add or delete photos. The haml for deleting photos looks like this, where variable is replaced with whatever view _form.html.haml is in:

.gallery#form
  - @VARIABLE.photo.each_with_index do |image, index|
    .overlay-container
      .img-square{ :style => "background-image: url(#{rails_blob_url(photo(@VARIABLE, index))})", :alt => "Photo of #{image}" }
      = link_to("Delete", delete_image_attachment_VARIABLE_url(image), method: :delete, class: 'button delete overlay')

To make the delete work on each photo, this code is in each controller:

  def delete_image_attachment
    @photo = ActiveStorage::Attachment.find(params[:id])
    @photo.purge
    redirect_back fallback_location: @VARIABLE
    flash[:success] = 'Photo was successfully deleted.'
  end

And routes.rb has this chunk of code for each model:

  resources :VARIABLE do
    member do
      delete :delete_image_attachment
    end
  end

However, I have about a dozen models I need to do this on. My goal is to bring the gallery into a new partial, since it will be used in every _form regardless of the other content. However, the delete function (though the same for every controller) is tied to the controller/routes.rb of each model.

There must be some way of DRYing this functionality into a couple files instead of copy-pasting for each model, but my Google searches have not turned up anything. So, any guidance or better Rails convention is greatly appreciated!

CodePudding user response：

If I'm understanding the structure properly, it sounds like you would want to do something like the following:

Create a top-level controller that handles deleting images

• This could be used by any page.
• This would require the following query parameters:
  • id the photo's ID to delete by.
  • redirect where to redirect the user after the action is completed.

Routes

Now there will only be 1 route to handle the controller above.

Create a reusable partial

For rendering a collection of images with a redirect url that allows you to set the following state for the partial:

• photos a collection of images to render.
• redirect_url this is passed as a query parameter to the centralized delete image controller.

Thoughts & Mocked Examples

This should be able to DRY up your implementation. Currently the only thing I see that couples the view with the deletion is the redirect URL. By abstracting that out and moving that essentially to a parameter for the partial will allow for re-use and flexibility.

You've already identified your coupling via @VARIABLE, here's a quick mock of how I would expect it to end up looking like:

Partial Template

.gallery#form
  - @photos.each_with_index do |image, index|
    .overlay-container
      .img-square{ :style => "background-image: url(#{rails_blob_url(photo(@VARIABLE, index))})", :alt => "Photo of #{image}" }
      = link_to("Delete", delete_image_attachment_url(image, redirect: @redirect_url), method: :delete, class: 'button delete overlay')

Ths would require: photos, and redirect_url So make sure to set @photos and @redirect_url on the consuming controller.

Example with instance properties to access in the template

@photos = GET_PHOTOS_HERE
@redirect_url = 'some-redirect-path'
render partial: 'photos_partial'

Example with locals parameter for the template

photos = GET_PHOTOS_HERE
render partial: 'photos_partial', locals: { photos: photos, redirect: 'some-redirect-path' }`

Note: You may need to change how you access the local variables in the template.

https://guides.rubyonrails.org/layouts_and_rendering.html#passing-local-variables

Controller

  def delete_image_attachment
    @photo = ActiveStorage::Attachment.find(params[:id])
    @photo.purge
    redirect_back fallback_location: params[:redirect]
    flash[:success] = 'Photo was successfully deleted.'
  end

Routes

Here you would only have the single route for deleting any image attachment, and point at the single controller above.

delete 'resources/image_attachment/:id', to: 'resources#delete_image_attachment'

Note: Replace "resources" with whatever your controller name is, or the scoping/naming you would like.

PS: It's been a while since I've done Rails so I'm not completely certain on the accuracy or your environment.