isset and forms

skeetley

I am having some troubles with my form. I have 2 pull down menus and two buttons. Both variables from the pull downs are passed when you push a button.

Everything in my form works fine except on the intial call of the page, the form script gets processed and with null variables, my error checking exits and I get my error message. This happens even with !isset and isset.

So how do I do this? I have tried many many ways and no luck.
My two buttons are:

<input type="submit" name="fwi" value="Get FWI">
		  <input type="submit" name="fbp" value="Get FBP">

and I want a simple way of saying if one of the buttons is pushed, execute the following. I have been trying the isset but is this wrong? Please help. Thanks.

paulnaj

There might be other ways, but here's one ...

1) Put a hidden form element in the form which stores the name of the button that was clicked to submit the form.

2) Use buttons instead of submits and use js to set the value of the hidden element and then submit the form

3) Use the hidden element value in the php 'response' page instead of checking the value of the button's.

Let us know if you need any help to do this!

keith73

post the code you're using to process the form. It's hard to guess what you're doing wrong.

keith

skeetley

Well I have tried many different approaches here, but this is the latest one:

$fwi = $_GET['fwi'];
$fbp = $_GET['fbp'];

if (!(isset($fwi))) { // Handle the form.
		$fwi=$_POST['fwi'];
	  	// Define a SQL Select Query
		$query = "SELECT * FROM ".$product.", Stations WHERE (".$product.".FMFP_ID=Stations.FMFP_ID) AND (Stations.grp IN(" . stripslashes($choice) . ")) AND (Stations.forecast LIKE 'y') ORDER by 'grp','pos'";
		if (!$result = mysql_query($query))
    	exit("Illegal query");

I am doing some reading now that paulnaj gave me a direction to look in.

I have also tried simpler stuff like:

if (isset($_POST['fwi'])) { // Handle the form.
	  	// Define a SQL Select Query

artic

Why are you using both $POST[] and $GET[]?

paulnaj

artic asked

Why are you using both $POST[] and $GET[]?

Do you mean, as opposed to $HTTP_VARS_XXXX? If so, it just the preferred way now.

Warboss_Alex

No, what he means, is why are you using BOTH the GET and POST arrays. A form's method is either GET -or- POST .. so a script which handles a form can't process the posted data as a querystring -and- in $_POST.

paulnaj

Oh, I see what he means now.

Why not just say that it's impossible to use both $GET and $POST for the same form, rather than answering questions with questions.

It's probably the cause of all the problems and neither of us noticed so far.

AstroTeg

I'm not sure this would fix it, but for $fwi, instead of checking if its set or not, maybe try this:

if($fwi != '')  // will be blank if form hasn't been submitted
{
  // code to process the form goes here
}  // end if(...

Paulnaj: It is very possible to use $GET and $POST in the same form. Here's the example:

<form action="my.php?Action=DoSomthing&ID=1" method="post">
<input type="text" name="test" value="datagoeshere">
</form>

This form will only work as a post. If you use get, the URL data that was added will be dropped (instead, you just add it as hidden form fields). In this example, you'd use $POST to retrieve form variable "test" and use $GET to retrieve URL variables "ID" and "Action".

paulnaj

Wow, that's interesting ... never thought of that before, but have definitely needed a solution like it.

Thanks.

chaotica

Note: Instead of the nasty line breaks and such, i marked my replies in color.
Red == my comments, blue == code i added, and silver == code i commented out.
No code has been deleted.

Originally posted by skeetley
Well I have tried many different approaches here, but this is the latest one:

[COLOR=red]// First off, if you don't know whether a request variable is set,
// an @ sign will suppress the warnings about undefined indices.
//[/COLOR][COLOR=silver]$fwi = [COLOR=blue]@[/COLOR]$_GET['fwi'];[/COLOR]
[COLOR=red]//[/COLOR][COLOR=silver]$fbp = [COLOR=blue]@[/COLOR]$_GET['fbp'];[/COLOR]
[COLOR=red]// Also, instead of waffling between using $_GET and $_POST, why not
// use $_REQUEST?  It's a combination of both arrays, so your script
// can handle GET *and* POST vars with very little effort.[/COLOR]

[COLOR=red]/*[/COLOR][COLOR=silver]if (!(isset($fwi))) { // Handle the form.
		$fwi=$_POST['fwi'];[/COLOR][COLOR=red]*/[/COLOR]
[COLOR=red]// In this case, there's really no need to store $fwi and $fbp, since
// their only use is to decide whether to get FWI or FBP.  So, instead of saving
// and then testing the value, it makes more sense to just test it directly.
// BTW, if you want to make sure the variable is actually set to something useful,
// as opposed to '', you could use !empty() instead of isset().[/COLOR]
[COLOR=blue]if (isset($_REQUEST['fwi'])) {  // Handle the form.[/COLOR]
	  	// Define a SQL Select Query
		$query = "SELECT * FROM ".$product.", Stations[COLOR=blue]"
			."[/COLOR] WHERE ".$product.".FMFP_ID = Stations.FMFP_ID)[COLOR=blue]"
			."[/COLOR] AND (Stations.grp IN(" . stripslashes($choice) . "))[COLOR=blue]"
			."[/COLOR] AND (Stations.forecast LIKE 'y') ORDER by 'grp','pos'";
		if (!$result = mysql_query($query))
    			exit("Illegal query");
[color=red]// I assume there's more code after this...most importantly a closing
// brace and an elseif (isset($_REQUEST['fbp'])) { ...[/color]

[/B]

A couple of other things i noticed:

In most cases, people would use mysql_escape_string() or addslashes() rather than
stripslashes() in the above code. I don't pretend to know what your variables are doing,
but unless you double-escaped them, stripslashes() will lead to a freaky SQL statement.
Instead of saying "some text " . $aVar . " some more text", it's usually cleaner
to say "some text $aVar some more text". Less punctuation to clutter up the
code. 🙂

AstroTeg

Originally posted by chaotica

[*]Instead of saying "some text " . $aVar . " some more text", it's usually cleaner
to say "some text $aVar some more text". Less punctuation to clutter up the
code. 🙂
[/list] [/B]

I'd like to disagree with you on this.

Reason 1: PHP is forced to do a little more work to parse a double quoted string to look for variables. Although not much of a slow down, it is additional processing work.

Reason 2: Variables do not stand out as quickly as they would if they were concatenated.

Reason 3: Other languages such as Java and ASP follow the concatenation pattern. This means when its time to port to one or the other, it'll be a little easier (can use global replace). I had the fun experience of converting PHP to Java and it went much quicker since the variables where using the cancatenation method.

Although to each their own. But the above reasons are good enough for me to concatenate most of the time (I will mix the variables every now and then - but its for quick little things).