[ic] Prevent from ordering more than is in stock

[interchange-users@icdevgroup.org (Interchange user)]

<<

> Hello,
>
> I have prevented out of stock orders (foundation demo) by conditionally
> displaying the quantity box / having an 'Add to cart' button clickable in
> the various pages (results.html, flypage.html, and the components such as
> random, etc.), by use of a [if-item-data inventory quantity > 0] tag. I
> also got rid of the 'Out Of Stock' and 'N' hyperlinks in flypage.html and
> results.html respectively.
>
> Is this sufficient to prevent people from ordering items that are out of
> stock?
>
>
> Also, the main reason for posting this; how can I prevent people from
> ordering more items than are in stock?
>
> A search of the archives revealed this:
> >  [item-calc]
> >  my $q = q{[item-data inventory quantity]};
> >  my $s = q{[item-quantity]};
> >  if($q < $s) {
> >  return <<EOF;
> >  <font size=1 face="arial, verdana, helvetica" color="#ff0000">
> >  Sorry, only $q available.
> >  <br></font></TD><TD ALIGN=CENTER>
> >  <INPUT onChange="this.form.submit()" TYPE=text NAME="[quantity-name]"
> >  VALUE=$q SIZE=3>
> >  EOF
> >  }
> >  else {
> >  return <<EOF;
> >  </TD><TD ALIGN=CENTER>
> >  <INPUT onChange="this.form.submit()" TYPE=text NAME="[quantity-name]"
> >  VALUE="[item-quantity]" SIZE=3>
> >  EOF
> >  }
> >  [/item-calc]
> >  </TD>
>
> This would go in checkout.html, in the cart section, but the problem here
> is that if someone arrives at the checkout page with more items than are in
> stock, or changes the quantity on the checkout page to more than is in
> stock, the incorrect price is displayed.
>
> The solution is very simple - all I have to do is set the item quantity to
> the inventory value for that item within the above 'if' statement, but HOW
> do I do this, either in ITL or Perl?

>>



>     I have this in my templates/components/cart.  Display q_message
> somewhere in your "error message" area of the cart and it will let users
> know if their order has been modified.  This code came out of this llist
> and seems to work well.
>
>     It should probably go in the ord/checkout file also, although I don't
> have it there because I don't have that much concurrency.  For sites with
> really high item concurrency at checkout there should probably be something
> in the etc/profiles.order also.  For sites with mega ultra crazy order
> volume and small stock quantities it might even be necessary to go beyond
> that, one might have to start doing some sort of encapsulation using a
> database transaction or a nasty semaphone to check the stock level and
> decrement it or kick the order back all in one autonomous, serialized
> operation.  But, man, if I ever get to that transaction volume I'll be able
> to pay someone else to do that while I sit on the beach and drink
> margaritas.  Until that point I will be using this:
>
> [comment]dont let users add more to cart than we have in stock[/comment]
> [perl tables=inventory]
>   my $item;
>   foreach $item (@{$Carts->{main}}) {
>     my $on_hand = tag_data('inventory', 'quantity', $item->{code});
>     next if $on_hand >= $item->{quantity};
>     if ($on_hand<=0) {
>       $item->{quantity} = 0;
>       $item->{q_message} = "Item is currently out of stock.";
>     } else {
>       $item->{quantity} = $on_hand;
>       $item->{q_message} = "Limited item stock, order quantity adjusted.";
>     }
>   }
> [/perl]
>
>
>
> Jeff


Thanks Jeff, that's just the type of thing I was looking for. I've put that 
at the top of ord/checkout.html, as I figure it should be parsed before 
anything else, but it doesn't seem to be having any effect on the quantities 
(I've restarted Interchange). Any ideas?



> How about a SQL query?
>
> [query sql="select quantity from inventory where sku = '[item-code]'"
> list=1]
> [sql-pos 0]
> [/query]
>
> In this example, "[sql-pos 0]" should pull the number in the inventory
> for the given sku.
>
> HTH

Sorry, I should have explained better. I'm OK on grabbing the inventory 
value; what I wanted to know is how to set the quantity of the current item 
(i.e. the value returned by [item-quantity].