Uploading a file in rails through Paperclip

As we know these days almost all the applications have the requirement to upload files to the application then be it an image , a video or any other file. I am writing this blog to share with you all a simple way of uploading an image file to your application. For that we will use Paperclip gem.

The steps are as fallows:

Step 1 : Go to your gemfile and add the paper clip gem to it.

gem "paperclip", "~> 3.0"

Then run command bundle install in your console.

Step 2 : Now create a model in which you have to store your attachment giving the name of the column as 'attached_file' and its data type as 'attachment'. let the model be Users. Now your user.rb file should look like thiis.

class User < ActiveRecord::Base
  has_attached_file :attached_file
end

And your migration file that is 20160511110347_create_user.rb should look like this 

class CreateUsers < ActiveRecord::Migration
  def change
    create_table :users do |t|
      t.attachment :attached_file
      t.timestamps
    end
  end
end

Step 3 : Creating the controller to get your file permitted and saved in the model. The create method will get the attached file in the params save it to the database through the model. Now your users_controller.rb file should look like this.

class UsersController < ApplicationController

  def index
    @users = User.all
  end

  def new
    @user = User.new
  end

  def create
    @user = User.new(user_params)

    if @user.save
      redirect_to action_path
    else
      render 'new' 
    end
  end

  private
    def user_params
      params.require(:user).permit(:attached_file)
    end
end

Step 4 :  Now finally creating the view of your application through which you will let the user to upload a file. Your new.html.erb fin the views/user folder should look like this.

<%= form_for :user , url: users_path do |f| %>
  <div class="field">
    <%= f.label :attached_file %><br>
    <%= f.file_field :attached_file %>
  </div>
<% end %>

And there you go. Now you have successfully uploaded a file to your database.