Nested hash from form params into create()?

Rails
1

Hi,

I’m really excited about getting the create() method working on a
nested hash. The Rails book make it seem like I’m close to doing the
right thing but I think something very small is not quite right. The
error at the below isn’t giving any hints that I understand.

I have a form that produces a nested params hash and sends it to my
add_to_cart controller method. Params contains a product variation_id
and a list of chosen options (eg. color, size, etc).

Any help greatly appreciated.

Thanks,
Peter

params =
{
“commit”=>“Add To Cart”,
“variation_id”=>“1”,
“cart_item_options”=>{“6”=>{“option_id”=>“74”},
“7”=>{“option_id”=>“97”},
“5”=>{“option_id”=>“47”}}
}

CONTROLLER

def add_to_cart
CartItem.create(params}
end

MODELS

class CartItem < ActiveRecord::Base
belongs_to :variation
has_many :cart_item_options
end

class CartItemOption < ActiveRecord::Base
belongs_to :cart_item
end

TABLES

CREATE TABLE cart_items (
id SERIAL,
variation_id INTEGER UNSIGNED NOT NULL
);

CREATE TABLE cart_item_options (
id SERIAL,
cart_item_id INTEGER UNSIGNED NOT NULL,
optional_id INTEGER UNSIGNED NOT NULL
);

ERROR

CartItemOptionalVariation expected, got Array

RAILS_ROOT: script/…/config/…
Application Trace | Framework Trace | Full Trace

/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/associations/association_collection.rb:128:in
raise_on_type_mismatch' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/associations/association_collection.rb:114:inreplace’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/associations/association_collection.rb:114:in
each' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/associations/association_collection.rb:114:inreplace’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/associations.rb:770:in
cart_item_optional_variations=' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/associations.rb:762:incart_item_optional_variations=’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1337:in
send' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1337:inattributes=’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1336:in
each' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1336:inattributes=’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1188:in
initialize_without_callbacks' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:236:ininitialize’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:449:in
new' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:449:increate’
./script/…/config/…/app/controllers/store_controller.rb:79:in
`add_to_cart’

2

Sorry, I posted an error from a bigger version of the problem. Here is
the smaller version’s error message. It seems like create() doesn’t
like having any extra stuff sent to it. However, I don’t think I
should have to remove commit from the params hash for it to work as
nicely as the rails book implies.

Thanks,
Peter

undefined method `commit=’ for #CartItem:0x27239bc

RAILS_ROOT: script/…/config/…
Application Trace | Framework Trace | Full Trace

/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1498:in
method_missing' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1337:insend’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1337:in
attributes=' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1336:ineach’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1336:in
attributes=' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:1188:ininitialize_without_callbacks’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/callbacks.rb:236:in
initialize' /usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:449:innew’
/usr/local/lib/ruby/gems/1.8/gems/activerecord-1.13.2/lib/active_record/base.rb:449:in
create' ./script/../config/../app/controllers/store_controller.rb:79:inadd_to_cart’