Administrate::Field::ActiveStorage

Things To Know:

To preview pdf files you need to install mupdf or Poppler.
To preview video files you need to install ffmpeg.
To preview Office files as pictures you need to install activestorage-office-previewer by basecamp

How To Use:

Add administrate-field-active_storage and mini_magick to your Gemfile (rails 6):

gem 'administrate-field-active_storage'
gem 'mini_magick'

for rails 5.x use the following

gem 'administrate-field-active_storage' -v 0.1.8

Install:

$ bundle install

`has_one_attached`:

Assuming your model name is Model and field name is attachment

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachment: Field::ActiveStorage,
  }
# ...

Then add :attachment to FORM_ATTRIBUTES and SHOW_PAGE_ATTRIBUTES. Adding :attachment COLLECTION_ATTRIBUTES will work but will probably look too big.

`has_many_attached`:

Assuming your model name is Model and field name is attachments the process is identical the only issue is that the form field isn't being permitted, in order to permit it we apply the following method to the dashboard:

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachments: Field::ActiveStorage,
  }

  # ...
  FORM_ATTRIBUTES = {
    #...
    :attachments
  }

  # permitted for has_many_attached
  def permitted_attributes
    super + [:attachments => []]
  end

I know it is not ideal, if you have a workaround please submit a PR.

Prevent N+1 queries

In order to prevent N+1 queries from active storage you have to modify your admin model controller, below an example for a model called User and with attached avatars

module Admin
  class UsersController < Admin::ApplicationController
    def scoped_resource
      resource_class.with_attached_avatars
    end
  end
end

Removing/Deleting an Attachment

In order to allow the user to delete an attachment using the admin dashboard you need to do the following:

create a controller action with a delete route
point the Field::ActiveStorage field to that route

here is an example (send the route name as a symbol):

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachment: Field::ActiveStorage.with_options({destroy_path: :custom_active_storage_destroy_path}),
  }
# ...

Your routes.rb file must point to a controller action with method delete which should contain the following piece of code (you can modify to your own liking). FOR SECURITY REASONS please check if the current user is allowed to remove such file

  def remove_attachment
    attachment = ActiveStorage::Attachment.find(params[:attachment_id])
    attachment.purge
    redirect_back(fallback_location: "/")
  end

url_only

Only the following needs to change in order for the field to be url_only

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachments: Field::ActiveStorage.with_options({url_only: true}),
    # ...
  }
  # ...
end

show_in_index

This will preview thumbnails in the index page and if you're using has_many it will show the first one as a thumbnail and a count of the total attached files

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachments: Field::ActiveStorage.with_options({show_in_index: true}),
    # ...
  }
  # ...
end

show_preview_size

Supply the size of the image preview inside the show page. Check out the mini_magic#resize_to_limit documentation

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachments: Field::ActiveStorage.with_options({show_preview_size:  [150, 200]}),
    # ...
  }
  # ...
end

direct_upload

If you want to upload directly from the browser to the cloud you can use direct_upload

class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachments: Field::ActiveStorage.with_options({direct_upload: true}),
    # ...
  }
  # ...
end

Don't forget to include ActiveStorage JavaScript. You can use rails generate administrate:assets:javascripts to be able to customize Administrate JavaScripts in your application.

Things To Do:

[x] upload single file
[x] adding image support through url_for to support 3rd party cloud storage
[x] use html 5 video element for video files
[x] use html audio element for audio files
[x] download link to other files
[x] preview videos
[x] preview pdfs
[x] upload multiple files
[x] find a way to delete attachments
[x] preview office files as pictures

Contribution Guide:

contributers are welcome (code, suggestions, and bugs).
please document your code.
add your name to the contribute.md.

Based on the Administrate::Field::Image template, and inspired by Administrate::Field::Paperclip.