[Resolved] [Resolved] [Resolved] A better form validation function?

n00854180t

I need a little help with the function I am writing for form validation.

Now I would like to make it so that this function can take an array as an argument, and will check all values in the array. Also, if the first conditional evaluates to false, I want a variable to be set that corresponds to the array used as an argument. I am just not sure how to go about it.

function checkFieldAlphaNum($field){
		 if($field != "" && !preg_match("/[^a-zA-Z0-9\.\-\ß\ä\Ä\ü\Ü\ö\Ö\ ]+$/s",$field)){
                        $displaybullet = FALSE;
                        $formComplete = TRUE;
                        return TRUE;
				   } else {
				   $displaybullet = TRUE;
		        $formComplete = FALSE;
 			return FALSE;
		}

}

n00854180t

Bump...

laserlight

I want a variable to be set that corresponds to the array used as an argument

not sure what you mean.

n00854180t

I just mean that if one of the values of the argument evaluates to false, I want an array that corresponds to the argument (so if array['3'] == false, array2['3'] == true) something like that. Is there any way to do this just by looping through the conditional statement with a for loop?

laserlight

well, you can pass another array as an argument, then fill this 2nd array while looping through the first array.

n00854180t

Not sure how exactly to do that...could you give an example? Sorry...

I appreciate your replies, by the way 🙂

laserlight

//loop through array and return false if any data is not numeric
//store these non-numeric data in 2nd array
function checkArrayNumeric($array, $non_numeric) {
	$flag = true; //set to false if any data is not numeric
	foreach ($array as $value) {
		if (!is_numeric($value)) {
			$non_numeric[] = $value;
			$flag = false;
		}
	}
	return $flag;
}

n00854180t

Alright, from your example I came up with this. Now lets say I have 3 form fields. I enter the following data: Alpha, 34, invalid&#

Now if I have a condition that is if ($arrTwo['3'] != "" && $formComplete == FALSE){ echo "Field is invalid"; } Would it work like that? I am just not comfortable with arrays really.

function checkFieldAlphaNum($arrOne, $arrTwo){ 
    $arrayLength = count($arrOne);
        for ($i = 0; $i < $arrayLength; $i++){ 
            if($arrOne != "" && !preg_match("/[^a-zA-Z0-9\.\-\ß\ä\Ä\ü\Ü\ö\Ö ]+$/s",$arrOne)){                         

                $flag = TRUE; 
                    $formComplete = TRUE; 
                        return TRUE; 
                    } else {
                $arrTwo[] = $i; 
            $flag = FALSe; 
        $formComplete = FALSE; 
    return FALSE; 
            } 
        return $flag;                

    }
}

n00854180t

Oh one more question. How to I make it so that the 3 form fields are an array?

Something like this?

 $array = array($_POST['fieldone'], $_POST['fieldtwo'], $_POST['fieldthree']);

laserlight

One big problem with your code is the over-use of the return statement.
Your for loop will never run past the first iteration, i.e. no point passing an array.

My code returns true if all the array elements are valid, and false if any one is invalid.

Do you want that, or do you want to loop through the array and determine if each individual element is valid or invalid?

n00854180t

Well I don't really need to return $flag at all. I can just make $arrTwo global.
It's the value of $arrTwo that I need.

Do you want that, or do you want to loop through the array and determine if each individual element is valid or invalid?

This is what I was after. See I want to make it so that if one of the fields is invalid, the array value that is set that corresponds ($arrTwo) can be used in an if statement so that I can echo an error message.

laserlight

Then you could use something like:

function checkFieldAlphaNum($arrOne, $arrTwo) {
	foreach ($arrOne as $key => $value) {
		if (/* NOT true condition */) {
			$arrTwo[$key] = $value;
		}
	}
}

Anything in $arrTwo is invalid.
if count($arrTwo) is greater than 0, you can display an "invalid data" message and loop through $arrTwo.
If not, then proceed by using $arrOne since it contains only valid data.

laserlight

Conversely,

function checkFieldAlphaNum($arrOne, $arrTwo) {
	$flag = true;
	foreach ($arrOne as $key => $value) {
		if (/* NOT true condition */) {
			$arrTwo[$key] = $value;
			$flag = false;
		}
	}
	return $flag;
}

if checkFieldAlphaNum() returns false, loop through $arrTwo for invalid data.
This eliminates the need to use count() on $arrTwo.

n00854180t

Okay, so as I understand it the code below should work like this.

I have 3 form fields. I enter the following data: Alpha, 34, invalid&#

Now if I have a condition that is if ($arrTwo['3'] != "" && $formComplete == FALSE){ echo "Field is invalid"; } Would it work like that?

function checkFieldAlphaNum($arrOne, $arrTwo){  

          foreach ($arrOne as $key => $value){  

            if($arrOne != "" && !preg_match("/[^a-zA-Z0-9\.\-\ß\ä\Ä\ü\Ü\ö\Ö ]+$/s",$arrOne)){                          

                    $formComplete = TRUE;  

                        return TRUE;  

                    } else { 
                $arrTwo[$key] = $value;    

        $formComplete = FALSE;  

    return FALSE;  

            }                  

    } 
}

laserlight

Let's examine the flow of control:
The foreach loop goes through the first iteration of the array.
This has the value "Alpha", which is identified as valid.
Local variable $formComplete is set to true.
The function returns true.

What happened?
The rest of the array never was processed.
Now what if the "invalid&#" value was first?

The foreach loop goes through the first iteration of the array.
This has the value "invalid&#", which is identified as invalid.
$arrTwo[$key] is set to "invalid&#", $key is presumably 0
Local variable $formComplete is set to false.
The function returns false.

Again, the rest of the array never gets processed, and $formComplete is quite useless.

My idea is to loop through the entire array first then determine if any data is invalid.
If it is, then we loop through the invalid data again via another array, which unfortunately may be somewhat inefficient.
The function returns true if the form is "complete", i.e. all given data is valid.
Otherwise, it returns false.
This, then, can be used to check if any data is invalid.

Another method is roughly what you described, which involves listing the invalid data on the fly.
In this case, we only need one array:

function checkFieldAlphaNum($array) {
	$flag = true;
	foreach ($array as $value) {
		if (/* invalid data */) {
			//error message stating data here
			$flag = false;
		}
	}
	return $flag;
}

n00854180t

Okay that would work, but how am I going to display my error message above the specific field that was invalid?

The reason I wanted to set the second array to correspond with the values in the first array was so that if a specific value in the array was invalid, I could test if the second array is true and echo an error.

laserlight

but how am I going to display my error message above the specific field that was invalid

If that is the case I would probably go with the 2 array solution.

The implementation itself really depends.
One idea is to echo the $invalid_array['variable_name'] as needed in the form.

n00854180t

I tried doing this, but it always echoes "Its not true".

<html>
      <head>
            <body>
                  <form method="post" action="<?php $PHP_SELF ?>">
                        <?php if($formComplete == FALSE && $arrTwo['1'] != ""){ echo "Please complete";} ?><input type="text" name="testTxt1"><br>
                               <?php if($formComplete == FALSE && $arrTwo['2'] != ""){ echo "Please complete";} ?><input type="text" name="testTxt2"><br>
                        <?php if($formComplete == FALSE && $arrTwo['3'] != ""){ echo "Please complete";} ?><input type="text" name="testTxt3"><br>
                  <input type="submit" name="submit">
            </form>
      </body>
</head>
</html>

<?php

$testTxtArr = array($_POST['testTxt1'], $_POST['testTxt2'], $_POST['testTxt3']);

if ($submit){
   checkFieldAlphaNum($testTxtArr);
   if ($formComplete == TRUE)
      {
          echo "It's true!";
      }
   else
   {
echo "Its not true!";
}
       }
           else
       {
   echo "NotSubmitted!";
}


global $formComplete;
global $arrayLength;                

global $arrTwo;
global $key;
$arrTwo = array("");

function checkFieldAlphaNum($arrOne){  

          foreach ($arrOne as $key => $value){  

            if($arrOne != "" && !preg_match("/[^a-zA-Z0-9\.\-\ß\ä\Ä\ü\Ü\ö\Ö ]+$/s",$arrOne)){                          

                    $formComplete = TRUE;  

                        //return TRUE;  

                    } else { 
                $arrTwo[$key] = $value;    

        $formComplete = FALSE;  

   // return FALSE;  

            }                  

    } 
}

?>

n00854180t

Thanks for the help laserlight, I finally got it to work.