rails ajax example

rails.md

Ruby on Rails Ajax example

1. Add remote: true option to link, button or form

# app/views/products/show.html.haml

button_to 'Add to Cart', line_items_path(product_id: product), remote: true

2. Stop the create action from redirecting to the index display if the request is for JavaScript. We do this by adding a call to respond_to() telling it that we want to respond with a format of .js:

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

3. Rails supports templates that generate JavaScript—the js stands for JavaScript. A .js.erb template is a way of getting JavaScript on the browser to do what you want, all by writing server-side Ruby code. Let’s write our first: create.js.erb. It goes in the app/views/line_items directory, like any other view for line items:

# app/views/line_items/create.js.erb
$('#cart').html("<%=j render(@cart) %>");         # renders app/views/carts/_cart.html.erb

This simple template tells the browser to replace the content of the element whose id is cart with that HTML.