Re: Lazy population of has_a child records

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--- Christopher Laco <mendlefarg@xxxxx.xxx> wrote:


> This is roughly:
> 
>     my $cart = Handle::Cart->new(...);
>     my $cart->add_to_items({
>         id => 123456,
>         sku => 'sku1',
>         price => 1.23
>     });
> 
>     my $order = Handel::Order->new($cart);
> 
>     [behind the scenees in new]
>     my $items = $cart->items;
>     while (my $item = $items->next) {
>         my %copy = %{$item};
> 
>         # reset some values, do some calulations
>         ....
>         # add copy of cart item into order items
>         $self->add_to_items(\%copy);
>     };
> https://secure.cafes.net/billing/Staff_/Punch/add.pl
> 
> No, much to my surprise, %copy is empty except for id eve though the
> items class has:
> 
> __PACKAGE__->columns(Essential => qw(id cart sku price));
> 
> Of course if I call something first:
> 
> 
>     [behind the scenees in new]
>     my $items = $cart->items;
>     while (my $item = $items->next) {
>         $item->sku; #this loads the data
>         my %copy = %{$item};
> 
>         # reset some values, do some calulations
>         ....
>         # add copy of cart item into order items
>         $self->add_to_items(\%copy);
>     };
> 
> 
> %copy now has all of the key/values. Does this mean that lazy
> population and stopping it via Essential only works on the class you
> are directly working with, and not child record classes returned via
> has_a/has_many?

The has_many method "items" that you call internally does an
"ItemClass->search(...)" which does an sql_Retrieve which selects essential
cols.    So lazy popping should work here. From reading docs i believe it is
intended to  be ubiquitous.    What happens if you don't don't use an iterator
and use a array assignment instead?



pjs


		
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