Rails - Jun 2006 - Newbie question about Agile Rails book - Delete from cart

I have been working through the Agile Web Development with Rails book 
doing the Depot tutorial. I have completed it and it works but I cant 
say I understand how and why.
My question is this "After adding products to the Cart, how do I then 
give users the option to delete just one item and not empty the whole 
cart?"
I''ve been playing around with all sorts of code, just making myself
more
confused.
Any suggestions very much appreciated

Bob

-- 
Posted via http://www.ruby-forum.com/.

Hi Bob,

If you don''t understand most of the tutorial then I think it you  
should consider following some other tutorials or better yet  
designing your own app... that will force you to understand what you  
are doing. Don''t worry, you''re not alone, it''s taken
me a long time
to wrap my head around RonR.

Anyway, to remove an item, I added this to my controller:

   def remove_item
     @cart = find_cart
     @cart.remove_cart_item(params[:id])
   end

And this to the cart model:

   # Method to remove a product/option from the cart
   def remove_cart_item(id)
     if @items.delete_if {|item| item.id == id.to_i }
       true
     else
       false
     end
   end


And finally I modified the initialize function in the CartItem class  
like so, so that each item in the @items array of the cart object  
would have a unique id:

   def initialize(product,option)
     @product = product unless product.nil?
     @option = option unless option.nil?
     @quantity = 1
     @id = Time.now.to_i
   end


Let me know if you don''t know what any of this code is doing.  
Basically it just removes the appropriate item from the @items array  
in the cart object based on the item id.

Take care,
Sean



On 25-Jun-06, at 11:45 PM, Bob Wickham wrote:
> I have been working through the Agile Web Development with Rails book
> doing the Depot tutorial. I have completed it and it works but I cant
> say I understand how and why.
> My question is this "After adding products to the Cart, how do I then
> give users the option to delete just one item and not empty the whole
> cart?"
> I''ve been playing around with all sorts of code, just making
myself
> more
> confused.
> Any suggestions very much appreciated
>
> Bob
>
> -- 
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails

Hi Sean,
Thanks for that.
I understand what your code is doing which is about where I am with most 
of Rails. How to get it to work is another matter.
I assume by this
> And finally I modified the initialize function in the CartItem class
> like so, so that each item in the @items array of the cart object
> would have a unique id:
> 
>    def initialize(product,option)
>      @product = product unless product.nil?
>      @option = option unless option.nil?
>      @quantity = 1
>      @id = Time.now.to_i
>    end
you mean the initialize function in Cart.rb as you say "modify" and 
thats the only occurrence of initialize.

Can you suggest how to code a ''remove item'' link on the 
display_cart.rhtml page.

Bob

-- 
Posted via http://www.ruby-forum.com/.

Hi Bob,

Sure, for each row in the table produced on the display cart page you  
can just add another column at the end with a link in it. So you just  
need to pass the correct action an id to the link_to helper.

The initialize method I''m referring to is in the CartItem class, not  
the Cart class. If you don''t have a CartItem class yet I guess it  
means it makes it''s appearance a bit later in the tutorial.

Take care,
Sean

On 26-Jun-06, at 12:51 AM, Bob Wickham wrote:
> Hi Sean,
> Thanks for that.
> I understand what your code is doing which is about where I am with  
> most
> of Rails. How to get it to work is another matter.
> I assume by this
>
>> And finally I modified the initialize function in the CartItem class
>> like so, so that each item in the @items array of the cart object
>> would have a unique id:
>>
>>    def initialize(product,option)
>>      @product = product unless product.nil?
>>      @option = option unless option.nil?
>>      @quantity = 1
>>      @id = Time.now.to_i
>>    end
>
> you mean the initialize function in Cart.rb as you say "modify"
and
> thats the only occurrence of initialize.
>
> Can you suggest how to code a ''remove item'' link on the
> display_cart.rhtml page.
>
> Bob
>
> -- 
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails

Sean O''Hara wrote:
> Hi Bob,
> 
> Sure, for each row in the table produced on the display cart page you
> can just add another column at the end with a link in it. So you just
> need to pass the correct action an id to the link_to helper.
> 
> The initialize method I''m referring to is in the CartItem class,
not
> the Cart class. If you don''t have a CartItem class yet I guess it
> means it makes it''s appearance a bit later in the tutorial.
> 
> Take care,
> Sean
Maybe we''re reading from different books, mines printed February 2006, 
as I''m up to the chapter on Testing and there isn''t any
mention of
CartItem (but I do have a LineItem class). I''ve looked through the 
completed code in the back of the book to make sure I haven''t missed 
anything.
Anyway, thanks for your advice. I''ll have a go at including it in my 
code.

Bob

-- 
Posted via http://www.ruby-forum.com/.

Hi Bob,

Yep, I was referring the the 2nd edition, which is currently  
available in beta form. There''s a lot of improvements an additions  
already in the beta of the 2nd edition. I think it''s worth upgrading.

Take care,
Sean

On 26-Jun-06, at 1:50 AM, Bob Wickham wrote:
> Sean O''Hara wrote:
>> Hi Bob,
>>
>> Sure, for each row in the table produced on the display cart page you
>> can just add another column at the end with a link in it. So you just
>> need to pass the correct action an id to the link_to helper.
>>
>> The initialize method I''m referring to is in the CartItem
class, not
>> the Cart class. If you don''t have a CartItem class yet I guess
it
>> means it makes it''s appearance a bit later in the tutorial.
>>
>> Take care,
>> Sean
>
> Maybe we''re reading from different books, mines printed February
2006,
> as I''m up to the chapter on Testing and there isn''t any
mention of
> CartItem (but I do have a LineItem class). I''ve looked through the
> completed code in the back of the book to make sure I haven''t
missed
> anything.
> Anyway, thanks for your advice. I''ll have a go at including it in
my
> code.
>
> Bob
>
> -- 
> Posted via http://www.ruby-forum.com/.
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails