Question

I’m building the checkout page for an e-commerce site, and I have a fairly long transaction that creates a new User model and a new Order model. I wrapped the creation of these models in a transaction so that if validation for one fails, the other isn’t hanging around in the database. Here’s the trimmed-down code in my OrdersController:

rescue_from ActiveRecord::Rollback, with: :render_new

def render_new
  render action: 'new'
end

ActiveRecord::Base.transaction do
  @user = User.new params[:user]
  unless @user.save
    raise ActiveRecord::Rollback
  end
  //More stuff
  ...
  @order = Order.new params[:order]
  ...
  unless @order.save
    raise ActiveRecord::Rollback
  end
end

The error I’m seeing is this:

Missing template orders/create, application/create with {:locale=>[:en], :formats=>[:html], :handlers=>[:erb, :builder, :coffee]}

I’m confused as to why its trying to render the templates orders/create and application/create instead of rendering orders/new.

Is there a better way to force the transaction to fail so that the rollback will occur?

Answer 1

I think the intention is a bit clearer when wrapping the transaction in a begin/rescue block.

def create
  begin 
    ActiveRecord::Base.transaction do
      @user = User.new params[:user]
      unless @user.save
        raise ActiveRecord::Rollback
      end
      //More stuff
      ...
      @order = Order.new params[:order]
      ...
      unless @order.save
        raise ActiveRecord::Rollback
      end
    end
  rescue ActiveRecord::Rollback
    render action: "new" and return
  end
end

You need to return in the create method, otherwise it’s execution will continue to the end of the method and Rails default render will occur (in this case it means attempting to find a create.___ template).

If you don’t like the begin/rescue block you can just add an and return to the raise lines

raise ActiveRecord::Rollback and return