Agile Web Development with Rails, Edition 4

Agile Web Development with Rails, Edition 4

11.4 Iteration F4: Hide an Empty Cart 11.2 Iteration F2: Creating an AJAX-Based Cart

11.3 Iteration F3: Highlighting Changes

Assign the current item to be the line item in question

edit app/controllers/line_items_controller.rb
  def create
    @cart = current_cart
    product = Product.find(params[:product_id])
    @line_item = @cart.add_product(product.id)
    respond_to do |format|
      if @line_item.save
        format.html { redirect_to store_url }
        format.js   { @current_item = @line_item }
        format.json { render json: @line_item,
          status: :created, location: @line_item }
      else
        format.html { render action: "new" }
        format.json { render json: @line_item.errors,
          status: :unprocessable_entity }
      end
    end
  end

Add the id to the row in question

edit app/views/line_items/_line_item.html.erb
<% if line_item == @current_item %>
<tr id="current_item">
<% else %>
<tr>
<% end %>
  <td><%= line_item.quantity %>&times;</td>
  <td><%= line_item.product.title %></td>
  <td class="item_price"><%= number_to_currency(line_item.total_price) %></td>
</tr>

Animate the background color of that row

edit app/views/line_items/create.js.erb
$('#cart').html("<%=j render @cart %>");
 
$('#current_item').css({'background-color':'#88ff88'}).
  animate({'background-color':'#114411'}, 1000);

Pull in the jquery-ui libraries

edit app/assets/javascripts/application.js
// listed below.
//
// Any JavaScript/Coffee file within this directory, lib/assets/javascripts, vendor/assets/javascripts,
// or vendor/assets/javascripts of plugins, if any, can be referenced here using a relative path.
//
// It's not advisable to add code directly here, but if you do, it'll appear at the bottom of the
// the compiled file.
//
// WARNING: THE FIRST BLANK LINE MARKS THE END OF WHAT'S TO BE PROCESSED, ANY BLANK LINE SHOULD
// GO AFTER THE REQUIRES BELOW.
//
//= require jquery
//= require jquery-ui
//= require jquery_ujs
//= require_tree .

11.4 Iteration F4: Hide an Empty Cart 11.2 Iteration F2: Creating an AJAX-Based Cart