Undefined index????

[mfos]

Hi
I have the following PHP error:

Notice: Undefined index: id in PATH_TO_MY_FILE on line 6

This is line 6:
$validid = pf_validate_number($_GET['id'], "value", $config_basedir);

Whats funny is that under OSX using apache php 4.4.4 I don't get this error (there are more but one at a time).

Under a windows server using PHP 4.3.2 I get the above error.

How is this and what can i do to get around it?

Cheers
Mike

[laserlight]

That looks strange, $_GET has been available since PHP 4.1.0

One possibility is that your OS X server is configured to ignore notices, but your Windows server is not. If so, you should fix it by checking if $_GET['id'] actually exists at that point in the code, using [man]isset/man, [man]empty/man or [man]array_key_exists/man.

[leatherback]

The difference between the two setups is the level of error reporting between the systems. You need it set to E_ALL to get these warnings. Develop using E_ALL, as you will remove most of the little bugs in your code, and produce solid code.

You get around it, by testing whether the ID is set:

if(! isset($_GET['id'])
  {// the id was not set, set it yourself with a default
  $_GET['id'] = 0;
  }

Better would be to have a function that retrieves the value for you, and verifies that it does not contain potenitally harmfull code. But I leave that up to you.

[mfos]

I'm using this function:

function pf_validate_number($value, $function, $redirect) 
	{
	if(isset($value) == TRUE) 
		{
		if(is_numeric($value) == FALSE) 
			{
			$error = 1;
			}

	if($error == 1) 
		{
		header("Location: " . $redirect);
		}
	else 
		{
		$final = $value;
		}
	}
else 
	{
	if($function == 'redirect') 
		{
		header("Location: " . $redirect);
		}

	if($function == "value") 
		{
		$final = 0;
		}
	}

return $final;
}

Which is set in:

$validid = pf_validate_number($_GET['id'], "value", $config_basedir);

Can't see why its giving me the error. Anyone?

[leatherback]

It is not the function giving the error, but the 'id' in $_GET['id'], as explained by laser and me in the previous posts: You need to check whether id is set.

[laserlight]

You should use isset() on incoming variables before passing them to functions.

[leatherback]

think along these lines:

function pf_validate_number($value, $function, $redirect)
    {
    if(isset($_GET[$value]))
        {
        if(! is_numeric($_GET[$value]))
            {
            header("Location: " . $redirect);
            }
        else
            {
            return $_GET[$value];
            }
        }
    else 
        { 
        if($function == 'redirect')
            {
            header("Location: " . $redirect);
            }

    if($function == "value")
        {
        $final = 0;
        } 
    }
}

$validid = pf_validate_number('id', "value", $config_basedir); 

[mfos]

Gettin a bit lost now. Tried applying isset to my validid =... bit and getting errors.

Been at this for days and just can't resolve it. I have a $_session doing the same thing so it must be isset that fixes it. Should I change my function above to the modified one last posted?

Still a newbie to all this.

Cheers
M

[laserlight]

Should I change my function above to the modified one last posted?

leatherback's idea is that since you should only use an incoming variable after it has been tested and is known to exist, you can pass the array index of that variable to the function, and then use isset() within that function. If you understand this, go ahead and use the code posted.

[leatherback]

If you place this just before your original code, it should work fine for now:

if(! isset($_GET['id']))
  {// the id was not set, set it yourself with a default
  $_GET['id'] = 0;
  } 

However, to make your function more portable, you should look at the function I sent you, and possibly use that instead (Without the need for the snipped in this post).

I cleaned your function a bit further, now looks like this:

function pf_validate_number($value, $function, $redirect)
    {
    if(isset($_GET[$value]))
        {
        if(! is_numeric($_GET[$value]))
            {
            header("Location: " . $redirect);
            }
        else
            {
            return($_GET[$value]);
            }
        }
    else
        {
        if($function == 'redirect')
            {
            header("Location: " . $redirect);
            }      

        else
            {
            return(0);
            }
        }
    } 

Just give both options a try and see what they do, and which you prefer

[laserlight]

Incidentally, it is often good practice to place an exit() right after a location header, since typically you do not want any possible remaining portions of the current script file to be executed.

[mfos]

Thanks for the advice both of you.

I've tried the new edited function and I seem to be getting the same error in my main page (where I call the function). Everything still works as it should but i'm getting errors which means my code is not clean.

I'll have another look but i'm still learning PHP and my knowledge is limited.

Cheers and thanks
M