[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?

Thanks in advance.