title: Current_user in Controller for Rails 4
body: <p>I have a <code>Listings Controller</code> where Users can Create their Listings.</p>
  
  <p>To prevent users to edit other users listings i just had to update every action from</p>
  
  <pre><code>Listing to current_user.listings
  </code></pre>
  
  <p>but with Rails 4 the controller got changed and i can't find how to set this up.</p>
  
  <p>My Controller File-></p>
  
  <pre><code>class ListingsController &lt; ApplicationController
    before_action :set_listing, only: [:show, :edit, :update, :destroy]
      before_filter :authenticate_user!, :only =&gt; [:index]
  
    # GET /listings
    # GET /listings.json
    def index
      @listings = Listing.all
    end
  
    # GET /listings/1
    # GET /listings/1.json
    def show
    end
  
    # GET /listings/new
    def new
      @listing = Listing.new
    end
  
    # GET /listings/1/edit
    def edit
    end
  
    # POST /listings
    # POST /listings.json
    def create
      @listing = Listing.new(listing_params)
  
      respond_to do |format|
        if @listing.save
          format.html { redirect_to @listing, notice: 'Listing was successfully created.' }
          format.json { render action: 'show', status: :created, location: @listing }
        else
          format.html { render action: 'new' }
          format.json { render json: @listing.errors, status: :unprocessable_entity }
        end
      end
    end
  
    # PATCH/PUT /listings/1
    # PATCH/PUT /listings/1.json
    def update
      respond_to do |format|
        if @listing.update(listing_params)
          format.html { redirect_to @listing, notice: 'Listing was successfully updated.' }
          format.json { head :no_content }
        else
          format.html { render action: 'edit' }
          format.json { render json: @listing.errors, status: :unprocessable_entity }
        end
      end
    end
  
    # DELETE /listings/1
    # DELETE /listings/1.json
    def destroy
      @listing.destroy
      respond_to do |format|
        format.html { redirect_to listings_url }
        format.json { head :no_content }
      end
    end
  
    private
      # Use callbacks to share common setup or constraints between actions.
      def set_listing
        @listing = Listing.find(params[:id])
      end
  
      # Never trust parameters from the scary internet, only allow the white list through.
      def listing_params
        params.require(:listing).permit(:title, :description)
      end
  end
  </code></pre>
  
  <p>Anyone knows a Solution ?</p>