On 2/4/06, Woei S. email@example.com wrote:
? @Item.DeliveryMethod.price : nil %>
But I’ve received an application error `@auction[DeliveryMethod][price]’
is not allowed as an instance variable name
Can someone please give me some pointers to what I might have
overlooked? I got that format from an earlier posting in this mailing
list, but it seems like I must have missed something.
A couple of things are going on here.
The form helpers are expecting to receive the names of instance
variables and methods (as strings) as their parameters.
text_field_tag ‘Item[DeliveryMethod][price]’ is going to look for an
instance variable called @Item[DeliveryMethod][price], which isn’t a
Each call to text_field or text_field_tag will only emit one
tag. You need to call it once for every field you need in the
Item has_many DeliveryMethods, but you’re treating it as a has_one
in the above code.
This is roughly how I’d go about what you’ve described:
class Item < ActiveRecord::Base
class DeliveryMethod < ActiveRecord::Base
@item = Item.find params[:id]
Other stuff here… and then…
<%= text_field ‘item’, ‘some_method_that_item_has’ %>
<%= text_field ‘item’, ‘something_else_singular’ %>
<% if @item.delivery_methods -%>
<%= render :partial => ‘delivery_method’, :collection =>
<% end -%>
_delivery_method.rhtml ### (partial form)
<% @delivery_method = delivery_method -%> # The helpers require
instance methods, but the partial creates a local variable.
<% i = delivery_method_counter -%> # I hate typing
delivery_method_counter a dozen times.
<%= text_field ‘delivery_method’, ‘price’, :index => i %>
You can do this without partials, via @item.delivery_methods.each, or
a ‘for’ loop, but I prefer the extra separation offered by the partial
Notice the use of the :index => option, which lets Rails know you’re
making an array of fields.
In the controller, params[:delivery_method] will contain a hash of all
the delivery methods.
params[:delivery_method].each do |index, value|
#index starts at ‘0’
#value contains whatever the user entered on the form.