Creating a resource that belongs_to another resource - ruby-on-rails

Question

Here are my relevant models:
class ListItem < ActiveRecord::Base
belongs_to :inventory_item
belongs_to :shopping_list
belongs_to :item
end
class ShoppingList < ActiveRecord::Base
has_many :list_items
belongs_to :user, :foreign_key => :user_id
end
class InventoryItem < ActiveRecord::Base
belongs_to :item, :foreign_key => :item_id
belongs_to :vendor
has_many :list_items
end
I want to have a button to create ListItems that belong to a user specified list that they own. The new ListItem also needs to be passed the respective :item_id and :inventory_item_id. Here's the relevant part of my current view:
<tr>
<% item.inventory_items.each do |product| %>
<td><%= button_to "#{product.price}",
{:controller => :list_items,
:action => 'create',
:id => #what goes here??,
:method => :create %></td>
<% end %>
</tr>
And my ListItems controller create method:
def create
ListItem.create
flash[:success] = "List Item Added."
redirect_to search_results_path(params[:search])
end
Clearly my create method isn't all that useful right now because it just creates a ListItem with no attributes other than :id. What's the best way to pass the appropriate parameters to my controller? Any help is much appreciated! Thanks in advance.

Answer 1

After doing a bunch of snooping around SO etc. I think the best way to accomplish this is to use a form with hidden fields, as below:
<%= form_tag("/list_items", method: "post") do %>
<%= hidden_field_tag(:item_id, item.id) %>
<%= hidden_field_tag(:inventory_item_id, product.id) %>
<%= hidden_field_tag(:shopping_list_id, ShoppingList.first.id) %>
<%= submit_tag("#{product.price}") %>
This is working well for me and is cleaner in this instance than using a button_to.