Active admin and Paperclip

1. Gemfile
gem 'activeadmin-ckeditor'
gem 'activeadmin', github: 'activeadmin'
gem 'devise'
gem 'paperclip'
gem 'ckeditor'#, github: 'galetahub/ckeditor'

2. app/admin/page.rb

ActiveAdmin.register Page do
permit_params :title, :content, :image

# CKEDITOR
form do |f|
  f.inputs do
    f.input :title
    f.input :image, :required => false, :as => :file
    f.input :content, :as => :ckeditor
  end
  f.submit
end

index do
  column :title
  actions
end

show do |ad|
 attributes_table do
  row :title
  row :image do
   image_tag(ad.image.url(:thumb))
  end
  # Will display the image on show object page
 end
end 

end




3. app/models/page.rb

class Page < ActiveRecord::Base
 has_attached_file :image, :styles => { :medium => "300x300#", :thumb => "200x200#" }
 validates_attachment_content_type :image, :content_type => /\Aimage\/.*\Z/
end 



4. Run

rails generate paperclip page image 

rake db:migrate
 

5. Run on your linux

sudo apt-get install imagemagick 

It will prevent from error "Image Could not run the `identify` command. Please install ImageMagick."