rails_website_template/app/controllers/blog_posts_controller.rb

class BlogPostsController < ApplicationController
  
  before_filter :authenticate_user, only: [:edit, :update, :destroy]
  
  before_action :set_blog_post, only: [:show, :edit, :update, :destroy]

  # GET /blog_posts
  # GET /blog_posts.json
  def index
    @blog_posts = BlogPost.all
  end

  # GET /blog_posts/1
  # GET /blog_posts/1.json
  def show
  end

  # GET /blog_posts/new
  def new
    @blog_post = BlogPost.new
  end

  # GET /blog_posts/1/edit
  def edit
  end

  # POST /blog_posts
  # POST /blog_posts.json
  def create
    @blog_post = BlogPost.new(blog_post_params)
    @blog_post.update(:author => current_user) 
    respond_to do |format|
      if @blog_post.save
        format.html { redirect_to @blog_post, notice: 'Blog post was successfully created.' }
        format.json { render action: 'show', status: :created, location: @blog_post }
      else
        format.html { render action: 'new' }
        format.json { render json: @blog_post.errors, status: :unprocessable_entity }
      end
    end
  end

  # PATCH/PUT /blog_posts/1
  # PATCH/PUT /blog_posts/1.json
  def update
    respond_to do |format|
      if @blog_post.update(blog_post_params)
        format.html { redirect_to @blog_post, notice: 'Blog post was successfully updated.' }
        format.json { head :no_content }
      else
        format.html {  }
        format.json { render json: @blog_post.errors, status: :unprocessable_entity }
      end
    end
  end

  # DELETE /blog_posts/1
  # DELETE /blog_posts/1.json
  def destroy
    @blog_post.destroy
    respond_to do |format|
      format.html { redirect_to blog_posts_url }
      format.json { head :no_content }
    end
  end
  


  private
    # Use callbacks to share common setup or constraints between actions.
    def set_blog_post
      @blog_post = BlogPost.friendly.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def blog_post_params
      params.require(:blog_post).permit(:title, :slug, :content, :published, :description, :image)
    end
    
    def authenticate_user 
      redirect_to root_path, alert: 'You dont have permission to access that page!' unless current_user && current_user.admin?
    end
end