PHP Question about POST data

BrianK · 11-25-2005, 10:27 PM

I'm getting a bunch of POST data from paypal. In that data, there exists a variable "item_nameX" where X is a number based on the number of different items the person ordered... so I get item_name1, item_name2, item_name3 and so on.

I can access the data with $_POST['item_name1']; but because I don't know how many there are, I've put the assignment in a little loop:

Code:

$i="1";
while(true)
{
  $key = "item_name" . $i;
  $item_name[$i] = $_POST['$key'];
  if ($item_name[$i] = " ")
    break;
  ++$i;
}

..but that doesn't work. Evidently, I can't use "$key" like that because it doesn't work.

Is there some way to do this in a loop? Can you use a variable as a POST array index?

rylan76 · 11-25-2005, 11:41 PM

Hi Brian,

I've done exactly this - your logic is correct, something else must be wrong. I. e. I have a form being posted that contains 10 fields, and I enumerate all 10 fields when processing the form using

$fieldname = "form_field_";

$counter = 0
$num_fields = 10;

while ($num_fields > 0)
{
$result = $HTTP_POST_VARS[$fieldname + $counter];

//work with result

$counter++; //Whoops!

$num_fields--;
}

This enumerates all 10 fields correctly... I suspect something else must be awry though I can't spot it, since your code seems 100% correct.

LiquidFire · 11-26-2005, 02:14 AM

First of all, I'm not sure if this is the cause of the problem, but wouldn't the index of the array be without quotes, or is $_POST an exception or something? Also, wouldn't it be better using a for loop rather than a while loop, much cleaner

Code:

for($i="1"; true; $i++)
{
  $key = "item_name" . $i;
  $item_name[$i] = $_POST[$key];
  if ($item_name[$i] = " ") break;
}

spooon · 11-26-2005, 04:20 AM

I'm not sure if your condition for ending the loop works. I would do something like this:

Code:

for ($i = 1; true; $i++)
{
  $temp = $_POST["item_name$i"];
  if (isset($temp))
    $item_name[$i] = $temp;
  else
    break;
}

graemef · 11-26-2005, 08:40 AM

Okay you want your loop to see if the variable has been set up. This can be done as follows:

Code:

while (is_set($_POST["item_names$i"]))
{

   // do something with $_POST["item_names$i"]
  $i++;

}

graeme.

keefaz · 11-26-2005, 09:08 AM

I would do :

PHP Code:



$item_name = Array(); 
foreach($_POST as $key => $val) { 
    if(strpos($key, 'item_name') !== FALSE) { 
        $item_name[] = trim($val); 
    } 
}

rylan76 · 11-26-2005, 11:25 AM

Quote:

Originally posted by LiquidFire
First of all, I'm not sure if this is the cause of the problem, but wouldn't the index of the array be without quotes, or is $_POST an exception or something? Also, wouldn't it be better using a for loop rather than a while loop, much cleaner

Code:

for($i="1"; true; $i++) { $key = "item_name" . $i; $item_name[$i] = $_POST[$key]; if ($item_name[$i] = " ") break; }

Sure, the loop type doesn't matter - I think the quotes don't matter... not sure though. Oh, and rather make

if ($item_name[$i] = " ") break;

like this (my opinion only!)

if (strcasecmp($item_name[$i]," ") == 0) break;

Regards,

BrianK · 11-26-2005, 01:33 PM

Thanks for the help guys - finally got it working.

My first major problem was '=' instead of '==' in the if test. Because it was an assignment, it was always true, so it always broke out of the loop.

Secondly, the test was wrong, I should have been using empty(). (BTW: isset didn't work - at least I couldn't get it working... I don't know why it didn't work when checking the $_POST array, but I can see it wouldn't work after the assignment, because you just set it to nothing).

The for loop does look much cleaner.

working:

Code:

for($i="1"; $i<100; $i++)
{
  $key = "item_name" . $i;
  $item_name[$i] = $_POST[$key];
  // lots of other variable assignments here
  if (empty($item_name[$i]))
    break;

}

the $i<100 keeps out of infinite loops if something goes wrong

Thanks again!