On 10/2/07, [EMAIL PROTECTED] <[EMAIL PROTECTED]> wrote:
> i am using cgi session to write a cart .
> here is the partial code.
If you only send part of your code, ideally you should send a part
which can run on its own. That is, make a small stand-alone program
which shows the problem you're having, if you can.
> the problem is for loop will push mutiply times of same value if
> itemID is not exit in original array.
I think you mean to say that, if itemID doesn't exist in some original
array, your for loop pushes many copies of the same item onto some
array.
> what i want is only push one times of value if itemid is a new
> value
Are you having trouble testing that condition, that itemID is a new value?
> the cookie show below
> $D = {_SESSION_ID => 'de6426230428fcf1656dd0e79bc8cf88',_SESSION_ATIME
> => 1191284433,CART => [{name => '1_t-shirt',quantity => 7,price =>
> '14.99',itemID => '1001'}],_SESSION_EXPIRE_LIST =>
> {},_SESSION_REMOTE_ADDR => '192.168.1.170',_SESSION_CTIME =>
> 1191284098};
Cookie data like that looks as if you're storing the shopping cart
data within the cookie itself. That can work, but it's open to
potential abuse. (Can a potential client change the price on an item
that's in the cart, simply by editing the cookie file on their
system?) Also, it restricts the user to complete the transaction from
that very browser, perhaps from that very session.
I would generally decouple things further. I'd have a single cookie
that represents the session; at my end, the session data shows which
user is authenticated in that session, and what their shopping cart
contains. If the user's browser quits (or crashes), they have to log
in again, at which point I'd ask whether they want to continue with
their saved shopping cart or to start with a new one. They may want to
buy some things with a new cart, without losing their partial cart;
for example, if they need to make one purchase with their work credit
card and a second with another payment source. Or perhaps Dilbert
fills the shopping cart with 93 items from his own computer, but it's
the Pointy-Haired Boss who needs to take over the cart at his own desk
to approve the order and make the payment.
> use cgi::session
Is that right? Is it capitalized properly? Where's the semicolon at
the end of the line?
> %products = (
> 1001=> [ "1_usr/bin/perl t-shirt", 14.99],
> 1002 => [ "2_just perl t-shirt", 21],
> 1003 => [ "3_shebang hat", 31],
> 1004 => [ "4_linux mug", 41],
> 1005 => [ "5_itme5", 51],
> # on and on it goes....
> );
I hope you're keeping your product data and prices in a database, with
this merely being example code.
> sub add_item {
> my ($cgi, $session, $products) = @_;
> # getting the itemID to be put into the cart
> my $itemID = $cgi->param("itemID") || &error ("$! ( No item
> specified ) ");
Is that right? Is precedence doing what you want, or do you need more
parentheses? What's going to be in $! when the parameter isn't
specified? Unless the param method is going to set $! (which it might,
but doing so isn't standard practice) you'll find some leftover
message like "bus error" that's only going to confuse whoever gets to
debug your program.
I suspect that you want to handle the lack of itemID in some special
way. How you handle it depends upon what it means, though; what does
it mean to your application that the itemID is missing? Does it mean
that the user has mis-filled the form, or does it mean that your
program is being invoked before the user can fill the form?
> # getting the current cart's contents:
> my $cart = $session->param("CART") || [];
>
> for my $product ( @{$cart} ) {
>
> if ( $product->{itemID} == $itemID) { updateitem_quantity }
> else (
> push @{ $cart }, {
> itemID => $itemID,
> name => $products->{$itemID}->[0],
> price => $products->{$itemID}->[1],
> quantity => $quantity
>
> };
>
> }
That looks like problem code: you're modifying the cart (@{ $cart })
while you're in a for loop, iterating over that same array. That's a
bad idea, even if it seems to work. And it doesn't seem to be working
here.
I think what you really intend to do there is, update the one item,
but leave the others alone. In other words, the else clause code,
which pushes another item onto the cart, is either useless, or it's
code you intended to place elsewhere in your algorithm.
Good luck with it!
--Tom Phoenix
Stonehenge Perl Training
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