maybe you miss the code in the book: file: line_item.rb belong_to :product belong_to :cart
then, the line_item has the attr product. On Sunday, April 8, 2012 7:14:31 AM UTC+8, Ruby-Forum.com User wrote: > > I am new to Ruby and to Rails (using Ruby 1.9.3 and Rails 3.2.3) so I > picked up the Agile Web Development book and have been working through > it (apologies if this isn't the correct place for this question but the > pragprog forums don't seem to work for me). I am currently working > through the book and have reached the point where I am adding > functionality to an "Add to Cart" button. Here is the code that was > provided for the 'create' method in the line_item_controller: > > def create > > @cart = current_cart > product = Product.find(params[:product_id]) > @line_item = @cart.line_items.build(product: product) > > ... > > end > > This results in the following error when I click "Add to Cart" > > Can't mass-assign protected attributes: product > > Can anyone shed some light on what is going on here (my search-fu has > failed me)? The only way that I have been able to get this to work is > by changing the code (starting at @line_item) to: > > @line_item = @cart.line_items.build > @line_item.product = product > > Is this correct or is it just a band-aid fix that may cause issues going > forward? > > Thanks, > > -- > Posted via http://www.ruby-forum.com/. > > -- You received this message because you are subscribed to the Google Groups "Ruby on Rails: Talk" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/rubyonrails-talk/83006756-e583-4fd6-8447-5deb2a82bc3f%40googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
