gistfile1.rb

before_action :set_project, only: [:show, :edit, :update, :destroy]

#snip....

  # GET /projects/1/edit
  def edit
  end

#snip...

  private
    # Use callbacks to share common setup or constraints between actions.
    def set_project
      @project = Project.find(params[:id])
    end

    # Never trust parameters from the scary internet, only allow the white list through.
    def project_params
      params.require(:project).permit(:name, :designer)
    end
end