[RESOLVED] shopping cart problem (extra item is being added)

[yahyac]

Okay, getting somewhere now. But something weird is happening. And it may be very simply and my tired head can't just see something obvious in front of me.

Let's say, for example, there are two items in the cart, and then on the mycart.php page, I iterate through the cart and print out various things into a table...each cart item gets its own table.

So if i had two items, i will get two tables, three items---three tables, and so forth.

The weird thing is that for any number of items in the cart (let's say that number is x), I get x+1 tables. So if there are 4 items, i get 5 tables. The first table does not priint out anything, because the value it gets from the $_SESSION array is apparently garbage. Then the next four tables are printing correctly.

Here's my code at the top of the page. This code basically checks to see how one came to this page. If $POST['type'] is set, that means that arrived at the page via posting an order/request form. So I first save that particular post to the $SESSION.

<?php
	$prodID = $_POST['prodID'];
	include('../global/dbinfo.php');
	$conn = mysql_connect($dbhost, $dbuser, $dbpass);
	mysql_select_db($dbname, $conn);
	$result = mysql_query("SELECT * FROM products WHERE item_num='$prodID'", $conn);
	if (!$result) {
		echo 'No results from query:  '.mysql_error();;
		exit;
	}
	$myrow = mysql_fetch_array($result);
	if (isset($_POST['type'])) {
		if (isset($_SESSION['cart']['numitems'])) {
			$_SESSION['cart']['numitems']+=1;
		}
		else {
			$_SESSION['cart']['numitems'] = 1;
		}
		$index = $_SESSION['cart']['numitems'];
		$type = $_POST['type'];
		if ($type == "Order") {
			$productDetails = array("type"=>$type,
			                        "prodID"=>$prodID,
			                        "qty"=>$_POST['qty'],
			                        "pColor"=>$_POST['pColor'],
			                        "IHdate"=>$_POST['IHdate'],
			                        "textlayout"=>$_POST['textlayout'],
			                        "textimprintcolor"=>$_POST['textimprintcolor'],
			                        "textinfo"=>$_POST['textinfo'],
			                        "logodescription"=>$_POST['logodescription'],
			                        "logoimprintcolor"=>$_POST['logoimprintcolor'],
			                        "textlayout"=>$_POST['textinfo'],
			                        "artfile"=>$_POST['artfile'],
			                        "addlnotes"=>$_POST['addlnotes']);
			$_SESSION['cart'][$index] = $productDetails;
		}
		elseif ($type == "Information Request") {
			$productDetails = array("type"=>$type,
			                        "prodID"=>$prodID,
			                        "addlnotes"=>$_POST['addlnotes']);
			$_SESSION['cart'][$index] = $productDetails;
		}
	}
?>

Next, later down the page, I want to iterate through the cart IF the cart has contents. Here's that code:

<?php
	// Check to see if the cart has anything at all
	if (isset($_SESSION['cart']['numitems'])) {
		// cart has stuff.  So iterate through the cart array.
		foreach ($_SESSION['cart'] as $productArray) {
			// Get the prodID from the productArray and run a query on this prodID
			$prodID = $productArray['prodID'];
			$result = mysql_query("SELECT * FROM products WHERE item_num='$prodID'", $conn);
			if (!$result) {
				echo 'No results from query:  '.mysql_error();;
					exit;
			}
			// We only care about the first row, as there may be a couple of duplicates
			$myrow = mysql_fetch_array($result);
			echo '<table width="100%" cellpadding="0" cellspacing="0" bgcolor="#181EA5">';
			echo '   <tr>';
			echo '      <td width="100%">';
			echo '         <table width="100%" cellpadding="" cellspacing="1">';
			echo '            <tr>';
			echo '               <td width="77%" valign="middle" align="left" class="content8" bgcolor="#FFFFFF">';
			echo '                  <table width="97%" align="center" border="0" cellpadding="0" cellspacing="0">';
			echo '                     <tr>';
			echo '                        <td class="content9b" colspan="2">' . $myrow['name'] . '<br><br></td>';
			echo '                     </tr>';
			echo '                     <tr>';
			echo '                        <td width="15%" class="content7">Item #: </td>';
			echo '                        <td width="85%" class="content7">' . $myrow['item_num'] . '</td>';
			echo '                     </tr>';
			echo '                     <tr>';
			echo '                        <td width="15%" class="content7">Notes: </td>';
			echo '                        <td width="85%" class="content7">' . $productArray['addlnotes'] . '</td>';
			echo '                     </tr>';
			echo '                     <tr>';
			echo '                        <td width="15%" class="content7">Type: </td>';
			echo '                        <td width="85%" class="content7">' . $productArray['type'] . '</td>';
			echo '                     </tr>';
			echo '                  </table>';
			echo '               </td>';
			echo '               <td width="23%" align="center" rowspan="2" bgcolor="#FFFFFF">';
			echo '                  <img src="/images/prod_cat/' . $myrow["catID"] . '/' . $myrow["subcatID"] . '/' . $myrow["item_num"] . 's.jpg"></td>';
			echo '            </tr>';
			echo '            <tr>';
			echo '              <td bgcolor="#EEEEEE">&nbsp;</td>';
			echo '            </tr>';
			echo '         </table>';
			echo '      </td>';
			echo '   </tr>';
			echo '</table><br>';
		}
	}
	else {
		echo '<div align="center">';
		echo '<table width="90%" cellpadding="1" cellspacing="0" bgcolor="#181EA5">';
		echo '   <tr>';
		echo '      <td>';
		echo '         <table width="100%" cellpadding="7" cellspacing="0" bgcolor="#E2E1E1">';
		echo '            <tr>';
		echo '               <td align="center" class="content9b">Your cart is empty.</td>';
		echo '            </tr>';
		echo '         </table>';
		echo '      </td>';
		echo '   </tr>';
		echo '</table>';
		echo '</div>';
	}
?>

Please excuse the "newbie" use of echo's. Oh well. 😃

So if you are able to take a look at that code, and somehow weave your way through my (perhaps crazy) logic, why is the output showing an additional table? Is that something specific with the foreach instruction. Please know, I am very new at this, so maybe this is something in the foreach iteration that I am not aware of. But if there are only two items in $SESSION['cart'], then shouldn't the foreach loop only go two times? And if your answer is yes, then the other thing i tried to realize was that, okay, then that means that somehow I'm "adding" a set of blank data to $SESSION['cart'] before I add the first product. But I can't see how/where this is happening.

Hope this makes a bit of sense and one of you geniuses can help out.

Thanks.

[yahyac]

btw, I changed the foreach loop to include the $key, as I wanted to print out the actual value of the key to see what was stored in there and why we were getting an extra iteration. Here's the modified code:

			foreach ($_SESSION['cart'] as $key => $productArray) {
				// Get the prodID from the productArray and run a query on this prodID
				$prodID = $productArray['prodID'];
				$result = mysql_query("SELECT * FROM products WHERE item_num='$prodID'", $conn);
				if (!$result) {
					echo 'No results from query:  '.mysql_error();;
						exit;
				}
				// We only care about the first row, as there may be a couple of duplicates
				$myrow = mysql_fetch_array($result);
				echo '<table width="100%" cellpadding="0" cellspacing="0" bgcolor="#181EA5">';
				echo '   <tr>';
				echo '      <td width="100%">';
				echo '         <table width="100%" cellpadding="" cellspacing="1">';
				echo '            <tr>';
				echo '               <td width="77%" valign="middle" align="left" class="content8" bgcolor="#FFFFFF">';
				echo '                  <table width="97%" align="center" border="0" cellpadding="0" cellspacing="0">';
				echo '                     <tr>';
				echo '                        <td class="content9b" colspan="2">' . $myrow['name'] . '<br><br></td>';
				echo '                     </tr>';
				echo '                     <tr>';
				echo '                        <td width="15%" class="content7">Item #: </td>';
				echo '                        <td width="85%" class="content7">' . $myrow['item_num'] . '&nbsp;,&nbsp;&nbsp;' . $key . '</td>';
				echo '                     </tr>';
				echo '                     <tr>';
				echo '                        <td width="15%" class="content7">Notes: </td>';
				echo '                        <td width="85%" class="content7">' . $productArray['addlnotes'] . '</td>';
				echo '                     </tr>';
				echo '                     <tr>';
				echo '                        <td width="15%" class="content7">Type: </td>';
				echo '                        <td width="85%" class="content7">' . $productArray['type'] . '</td>';
				echo '                     </tr>';
				echo '                  </table>';
				echo '               </td>';
				echo '               <td width="23%" align="center" rowspan="2" bgcolor="#FFFFFF">';
				echo '                  <img src="/images/prod_cat/' . $myrow["catID"] . '/' . $myrow["subcatID"] . '/' . $myrow["item_num"] . 's.jpg"></td>';
				echo '            </tr>';
				echo '            <tr>';
				echo '              <td bgcolor="#EEEEEE">&nbsp;</td>';
				echo '            </tr>';
				echo '         </table>';
				echo '      </td>';
				echo '   </tr>';
				echo '</table><br>';
			}
		}
		else {
			echo '<div align="center">';
			echo '<table width="90%" cellpadding="1" cellspacing="0" bgcolor="#181EA5">';
			echo '   <tr>';
			echo '      <td>';
			echo '         <table width="100%" cellpadding="7" cellspacing="0" bgcolor="#E2E1E1">';
			echo '            <tr>';
			echo '               <td align="center" class="content9b">Your cart is empty.</td>';
			echo '            </tr>';
			echo '         </table>';
			echo '      </td>';
			echo '   </tr>';
			echo '</table>';
			echo '</div>';
		}
	?>

Along with printing out the other stuff in the tables, if the are two items in the cart, for example, the following is printed out for $key:

iteration 1) numitems

iteration 2) 1

iteration 3) 2

So as mentioned, the extra, empty table is always printed out first, and now I at least get an idea of how this is happening. There is an extra $key in $_SESSION['cart']['numitems'], and that extra key is called 'numitems'. How? Why? No clue.

[tsinka]

Hi,

Check the following lines:

    // Check to see if the cart has anything at all
    if (isset($_SESSION['cart']['numitems'])) {
        // cart has stuff.  So iterate through the cart array.
        foreach ($_SESSION['cart'] as $key => $productArray) { 

The array $_SESSION['cart'] contains the items AND the value numitems so the foreach loop fetches the items numitems. So check if $key=='numitems' and ignore it.

But I wonder if numitems is neccessary at all. You can do something like count($SESSION['cart']) to get the number of items and use something like
$SESSION['cart'][] = $productDetails; to add the items.

Thomas

[yahyac]

Thomas, thanks for your help. As I'm new to php, perhaps I'm a bit slow on the uptake.

I really am not quite sure what you are saying. I thought isset worked as follows:

if (isset($_POST['type'])) {
	// here isset checks to see if the 'type', which is a key, is "set" in the array $_POST
	// if it is indeed "set", then isset returns true.
	// else, if nothing has been placed using 'type' as a key, then isset returns false
}

So wouldn't (isset($SESSION['cart']['numitems'])) simply check to see if $SESSION['cart']['numitems'] is "set", meaning, check to see if "numitems" has been used as a key in that 2d array?

Thanks.
Jonathan

[yahyac]

Okay, I changed my code a bit, as it was probably not best to keep 'numitems' in the second part of the array as I did. Actually, it was probably stupid. :bemused:

But I hope someone can still explain, just for my knowledge, how "isset" works and why I was getting that extra result.

Here's my changed code. I simply removed 'numitems' from 'cart' and made it on its own, as in $_SESSION['numitems']

<?php
	$prodID = $_POST['prodID'];
	include('../global/dbinfo.php');
	$conn = mysql_connect($dbhost, $dbuser, $dbpass);
	mysql_select_db($dbname, $conn);
	$result = mysql_query("SELECT * FROM products WHERE item_num='$prodID'", $conn);
	if (!$result) {
		echo 'No results from query:  '.mysql_error();;
		exit;
	}
	$myrow = mysql_fetch_array($result);
	if (isset($_POST['type'])) {
		if (isset($_SESSION['numitems'])) {
			$_SESSION['numitems']+=1;
		}
		else {
			$_SESSION['numitems'] = 1;
		}
		$index = $_SESSION['numitems'];
		$type = $_POST['type'];
		if ($type == "Order") {
			$productDetails = array("type"=>$type,
			                        "prodID"=>$prodID,
			                        "qty"=>$_POST['qty'],
			                        "pColor"=>$_POST['pColor'],
			                        "IHdate"=>$_POST['IHdate'],
			                        "textlayout"=>$_POST['textlayout'],
			                        "textimprintcolor"=>$_POST['textimprintcolor'],
			                        "textinfo"=>$_POST['textinfo'],
			                        "logodescription"=>$_POST['logodescription'],
			                        "logoimprintcolor"=>$_POST['logoimprintcolor'],
			                        "textlayout"=>$_POST['textinfo'],
			                        "artfile"=>$_POST['artfile'],
			                        "addlnotes"=>$_POST['addlnotes']);
			$_SESSION['cart'][$index] = $productDetails;
		}
		elseif ($type == "Information Request") {
			$productDetails = array("type"=>$type,
			                        "prodID"=>$prodID,
			                        "addlnotes"=>$_POST['addlnotes']);
			$_SESSION['cart'][$index] = $productDetails;
		}
	}
?>

And so I just changed the foreach loop as follows:

	<?php
		// Check to see if the cart has anything at all
		if (isset($_SESSION['numitems'])) {
			// cart has stuff.  So iterate through the cart array.
			foreach ($_SESSION['cart'] as $key => $productArray) {
				// Get the prodID from the productArray and run a query on this prodID
				$prodID = $productArray['prodID'];
				$result = mysql_query("SELECT * FROM products WHERE item_num='$prodID'", $conn);
				if (!$result) {
					echo 'No results from query:  '.mysql_error();;
						exit;
				}
				// We only care about the first row, as there may be a couple of duplicates
				$myrow = mysql_fetch_array($result);
				echo '<table width="100%" cellpadding="0" cellspacing="0" bgcolor="#181EA5">';
				echo '   <tr>';
				echo '      <td width="100%">';
				echo '         <table width="100%" cellpadding="" cellspacing="1">';
				echo '            <tr>';
				echo '               <td width="77%" valign="middle" align="left" class="content8" bgcolor="#FFFFFF">';
				echo '                  <table width="97%" align="center" border="0" cellpadding="0" cellspacing="0">';
				echo '                     <tr>';
				echo '                        <td class="content8b" colspan="2">' . $myrow['name'] . '<br><img border="0" src="/images/spacer.gif" width="1" height="4"></td>';
				echo '                     </tr>';
				echo '                     <tr>';
				echo '                        <td width="15%" class="content7">Item #: </td>';
				echo '                        <td width="85%" class="content7">' . $myrow['item_num'] . '&nbsp;,&nbsp;&nbsp;' . $key . '</td>';
				echo '                     </tr>';
				echo '                     <tr>';
				echo '                        <td width="15%" class="content7">Notes: </td>';
				echo '                        <td width="85%" class="content7">' . $productArray['addlnotes'] . '</td>';
				echo '                     </tr>';
				echo '                     <tr>';
				echo '                        <td width="15%" class="content7">Type: </td>';
				echo '                        <td width="85%" class="content7">' . $productArray['type'] . '</td>';
				echo '                     </tr>';
				echo '                  </table>';
				echo '               </td>';
				echo '               <td width="23%" align="center" rowspan="2" bgcolor="#FFFFFF">';
				echo '                  <a href="/products/item.php?prodID=' . $myrow["item_num"] . '">';
				echo '                  <img border="0" src="/images/prod_cat/' . $myrow["catID"] . '/' . $myrow["subcatID"] . '/' . $myrow["item_num"] . 's.jpg"></a></td>';
				echo '            </tr>';
				echo '            <tr>';
				echo '              <td bgcolor="#EEEEEE">&nbsp;</td>';
				echo '            </tr>';
				echo '         </table>';
				echo '      </td>';
				echo '   </tr>';
				echo '</table><br>';
			}
		}
		else {
			echo '<div align="center">';
			echo '<table width="90%" cellpadding="1" cellspacing="0" bgcolor="#181EA5">';
			echo '   <tr>';
			echo '      <td>';
			echo '         <table width="100%" cellpadding="7" cellspacing="0" bgcolor="#E2E1E1">';
			echo '            <tr>';
			echo '               <td align="center" class="content9b">Your cart is empty.</td>';
			echo '            </tr>';
			echo '         </table>';
			echo '      </td>';
			echo '   </tr>';
			echo '</table>';
			echo '</div>';
		}
	?>

So now that part is working.

[yahyac]

tsinka wrote:

But I wonder if numitems is neccessary at all. You can do something like count($SESSION['cart']) to get the number of items and use something like
$SESSION['cart'][] = $productDetails; to add the items.

Is numitems necessary? I have no clue; i'm very new at this. They ONLY reason I'm using a "counter" to keep track of the number of items is for the purposes of editing the cart, which I'll explain my funny logic below...and again, it may be CRAZY logic, as I'm shooting in the dark here with php.

On the mycart.php screen, where I show the contents of the cart, each item being in its own html table, I want to give two options for each item: modify or remove. So I was thinking, "okay, when someone hits modify, how do I code php to make sure it brings up the right item to modify? How will it know? So then, i thought, okay, well, i could index the $productDetails in the $SESSION['cart'] by using prodID as the key. However, because each product can be customized in its own unique way, it is definitely possible that one customer could order three of the same product. So that would mean that I would have three entries in the $SESSION['cart'] array with all three entries having the same key! So, i figured, that won't work.

That's when i decided to use numitems. It is basically just a way of assigning a unique number as a key for each item in the cart. Actually, when you think about it, numitems can't really even be used as a true "counter" of the items in the cart. Because if an item is deleted, and i decrease numitems, and then add another item to the cart, I will again run into the issue of duplicate keys. So therefore, when an item is deleted, I do NOT decrease numitems. Again, it is just a way of having a unique key to access the appropriate item within the 'cart' array. So when the mycart.php page displays, I can use this key (i'm assuming) to tell php to go edit the item whose key is "blah".

So that's my crazy usage of numitems.

Now, PLEASE, ANYONE, as i'm new as heck to this, if there is a better method, and you have the time to share, PLEASE feel free and tell me the way i coded is dumb and inefficient. I would seriously appreciate that! (well, as long as you advise on how to make it smarter and better)

Is there a better, more well-known way of accessing specific elements in an array, such as the one I have, if you do not know the exact key that you want to access?

Thanks.
Jonathan

[tsinka]

I was somewhat unclear ... I meant the second line of code, the foreach loop. $_SESSION['cart'] holds both the items and the numitems variable. In this case you only want to print the items and not numitems but foreach also fetches the numitems value so you need to ignore it.

Let's start with the original code ... something like this should solve the problem with the additional table:

....
....
foreach ($_SESSION['cart'] as $key => $productArray) { 
  if ($key == 'numitems') {
    // ignore numitems, which is part of the cart array but not an item
    continue;
  }
....
....

About numitems:
As far as I see that variable seems to hold only the number of items in the card. If this is the only purpose of numitems, then just remove it. You can just add items to the cart array and use count($_SESSION['cart']) to get the number of items in the cart.
There are several way to build an array:

$myArray[0] = 'a';
$myArray[1] = 'b';
$myArray[2] = 'c';
// and
$myArray[] = 'a';
$myArray[] = 'b';
$myArray[] = 'c';
// if you want the index to start with 1
$myArray[1] = 'a';
$myArray[] = 'b';
$myArray[] = 'c';

The first and the second example result in the same array, the third example makes the array to start with index 1 and count($myArray) will return the number of items in the array so I think that you don't need the numitems value in the cart array.

Additional notes:

1) predefine the cart array in the session to be an empty array at the beginning
2) it's better not to use $_SESSION directly inside the script especially if you modify session variables because that can lead to unexpected results. It's better to assign the session variables to variables at the beginning of the script and to store them at the end of the script if neccessary, something like:

<?PHP
// beginning
$arrCart = isset($_SESSION['cart']) ? $_SESSION['cart'] : array();
// the remaining code uses $arrCart
// at the end of the script
$_SESSION['cart'] = $arrCart;

3) this might not apply to your application but be careful with objects stored in the session with recent PHP versions >= 5.0.
Something like $myObj = $SESSION['obj']; will return a reference to the object stored in the session. Any modifications to $myObj will be written to the session even without doing something like $SESSION['obj'] = $myObj; at the end of the script.
4) Another important point to prevent problems if e.g. register_globals is set to On is, not to use variable names in a script that match the name of a session variable, something like

// there's a session variable $_SESSION['myvar']
$myvar = 0;

With register_globals set to On the last line of code would overwrite the session variable. I for example use a prefix of sess_ for session variables, something like

$_SESSION['sess_arrCart'] = array();
// and inside the scripts:
$arrCart = $_SESSION['sess_arrCart'];

to prevent problems like accidently overwriting session content.

But i didn't have set register_globals set to Off for a long time, it's too unsecure and leads to too many problems.

I hope I didn't write too much ... I left the thread topic a little bit. But I think the points above are very important.

Thomas

[yahyac]

tsinka, I think you and I were probably posting at the same time, so you may not have noticed my last post, as it came above yours. Just curious if there is a better way of accessing individual elements of the array, specific to my example, without knowing the exact key of the array element you want to access.

So as you can see in my explanation, that is the reason I used numitems. And use, I am actually counting the items, in my included header, with the count function.

Thanks.

[tsinka]

Ok,

I think PHP can do that automatically.
Example:

<?PHP
$myArray = array();
$myArray[] = 'a';
$myArray[] = 'b';
$myArray[] = 'c';
$myArray[] = 'd';
echo "<pre>";
print_r($myArray);
echo "</pre>";
unset($myArray[2]);
$myArray[] = 'e';
echo "<pre>";
print_r($myArray);
echo "</pre>";
?>

the first part builds an array with 4 items (indexes 0...3), then I unset the item with array index 2 and add another item just with $myArray[] without using a specific index. You'll see that the second print_r block prints and array with indexes 0,1,3,4. It just continues with maxkey+1.

Using a foreach ($myArray as $key => $data) you can loop through the array and build e.g. links to modify a given item and use $key as identifier.

This code behaves just like your code ... the only difference is that it doesn't use an additional variable to specify the index.

But this is a question of what you like more. To solve the main problem with that additional table using the existing code just add that "continue" code I posted.

Thomas

[yahyac]

I think I'm with you now. So although I'm not specifying keys, because the keys are simply incremented by one each time a new element is added, I can still access the automatically generated keys when I make my tables...just like you showed in the foreach loop you gave: foreach ($myArray as $key => $data)

So when I generate those tables, I can use that key, even though I don't know its value, I can still use that key to make links to the modify and remove functions/pages.

Correct?

[yahyac]

(uh oh), just on a side note, I just realized my name has "Senior Member" underneath...that sounds scary.

I'm not even a newbie....i'm a newbie wannabee.

[tsinka]

Yes, that's what I meant. The key is always unique if you go this way. PHP won't duplicate anything or mix up keys.

I'm not sure but I think the default status depends on the number of posts you have (101 in your case). It looks like PHP is counting all posts to one single thread as 1 post so it seems like you posted to 101 different threads.

Thomas

[yahyac]

Don't know if your still reading this, as I already marked it resolved, but a simply question for you on removing items.

Here's my code for linking to mycart.php on a remove action:

<a href="/products/mycart.php?removekey=' . $key . '">

So I simply call mycart.php with removekey=3 (for example)

Then, at the top of the mycart.php page, I do the following:

	if (isset($removekey)) {
		unset($_SESSION['cart'][$removekey]);	
	}

Based on your example, i thought this would work. Shouldn't it remove that particular key and its associated value(cart item)?

Thanks.

[yahyac]

Okay, I realized a stupid error, but I still can't get it to work. I was checking isset on a variable $removekey, when that variable had not been made yet. So here's the updated code:

	if (isset($_POST['removekey'])) {
		echo "key is set.  will remove it from cart.";
		$removekey = $_POST['removekey'];
		unset($_SESSION['cart'][$removekey]);	
	} else echo "not set";

This seems like it should work. Yet when I call mycart.php?removekey=1 (for example), it constantly prints out "not set".

[tsinka]

You need to use $GET to access get variables and $POST to access post variables (forms with method post). removekey is a get variable.

[yahyac]

sorry, i just did that. it is no longer printing "not set"

It IS printing "key is set. blahblah"

but it is not removing it when I iterate through the cart.

[tsinka]

Did you change the line $removekey = $_POST['removekey']; ?

It should be

$removekey = $_GET['removekey'];

Please post the current code.

[yahyac]

darn it. you beat me to it. i was just about to post that i made that dumb mistake.

Perhaps i should spend less time posting and more time looking at the code. :o

Thanks.
Jonathan