# Administrate::Field::ActiveStorage
![rails](https://img.shields.io/badge/rails-%3E%3D5.2.0-red.svg)

## 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](https://github.com/basecamp/activestorage-office-previewer) by basecamp

## How To Use:
Add `administrate-field-active_storage` and `mini_magick` to your Gemfile (rails 6):

```ruby
gem 'administrate-field-active_storage'
gem 'mini_magick'
```

for rails 5.x use the following
```ruby
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`
```ruby
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:

```ruby
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
```ruby
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:
1. create a controller action with a `delete` route
2. point the `Field::ActiveStorage` field to that route

here is an example (send the route name as a symbol):
```ruby
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
```ruby
  def remove_attachment
    attachment = ActiveStorage::Attachment.find(params[:attachment_id])
    attachment.purge
    redirect_back(fallback_location: "/")
  end
```

## Options

Various options can be passed to `Administrate::Field::ActiveStorage#with_options`
as illustrated below:

```rb
class ModelDashboard < Administrate::BaseDashboard
  ATTRIBUTE_TYPES = {
    attachments: Field::ActiveStorage.with_options(index_display_preview: false),
    # ...
  }
  # ...
end
```

### show_display_preview

Display attachment preview.

Defaults to `true`.

### index_display_preview

Displays the first attachment (which is the only attachment in case of `has_one`)
in the `index` action.

Defaults to `true`.

### index_preview_size and show_preview_size

Indicate the size of the image preview for the `index` and `show` actions, respectively.
Refer to [mini_magic#resize_to_limit](https://github.com/janko/image_processing/blob/master/doc/minimagick.md#methods)
for documentation.

Default to `[150, 150]` and `[800, 800]`, respectively.

### index_display_count

Displays the number of attachments in the `index` action.

Defaults to `true` if number of attachments is not 1.

### direct_upload

Enables direct upload from the browser to the cloud.

Defaults to `false`.

Don't forget to include [ActiveStorage JavaScript](https://edgeguides.rubyonrails.org/active_storage_overview.html#direct-uploads). 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:
1. contributers are welcome (code, suggestions, and bugs).
2. please document your code.
3. add your name to the `contribute.md`.

---
Based on the [Administrate::Field::Image](https://github.com/thoughtbot/administrate-field-image) template, and inspired by [Administrate::Field::Paperclip](https://github.com/picandocodigo/administrate-field-paperclip).