gistfile1.rb

  def update
    @product = Product.find(params[:id])
    respond_to do |format|
      if @product.update_attributes(params[:product])
        flash[:notice] = 'Product was successfully updated.'
        format.html { redirect_to(admin_product_path(@product)) }
        format.xml  do
          render :nothing => true, :status => :ok
          return true
        end
      else
        format.html { render :action => "edit" }
        format.xml  { render :xml => @product.errors, :status => :unprocessable_entity }
      end
    end
  end