Form Validation

korova

Hi
I'm trying to get some form validation working and I've tried hundreds of examples from the web, including the one here: http://phpbuilder.com/board/showthread.php?t=10317232&highlight=form+validation but it never works.

When I try the one at the above ilnk (by Houdini) the text boxes contain '<br />' when the page is initially loaded. If the form is submitted with incorrect data, the form reloads with the original data (ie '<br />' in the text boxes) and doesn't highlight the incorrect fields in red.

Do I have some incorrect settings somewhere? I've looked in php.ini but can't see anything relevant. I'm using PHP5.

I'd really appreciate some advice
Cheers

rincewind456

Check the source code and you'll find that the <br /> is part of an error message, usually for undefined indexs, fix them and the <br /> goes away

korova

Thanks for the reply. However, I still can't get the code from the above link working - I've literally copied and pasted it. The only line I have changed is to echo $error_msg rather than sending the output to javascript. I had changed

value="<? echo $POST[first_name_input]; ?>"
to
value="<?php echo $POST[first_name_input]; ?>"

now I've put it back I'm no longer getting ''<br />' in the text boxes, but instead I'm getting the whole line <?php echo $_POST[first_name_input]; ?> and the page still just resets when the form is submitted. This is similar to what I get when I've tried code from other sites.

I must be doing something wrong because the code worked for the op, any ideas?

Cheers

Houdini

I see where you apparently have short tags turned off which is why your code is working now. name the program whatever is in the action="?" This code will work (I just ran it on my own machine) if you name it simpleValid.php

<html>
<body>
<h3>PHP User Form</h3>
<?php
// only validate form when form is submitted Program name: form.php
if(isset($_POST[submit_button])){
    $error_msg='';
    if(trim($_POST[username_input])=='' || strlen(trim($_POST[username_input])) < 6 || strlen(trim($_POST[username_input])) > 15) {
        $error_msg.="Please enter a username between 6 to 15 characters long<br>";
    }
    if(trim($_POST[password_input])=='' || strlen(trim($_POST[password_input])) < 4) {
        $error_msg.="Please enter a password at least 4 characters long<br>";
    }
    if(trim($_POST[email_input])=='') {
        $error_msg.="Please enter an email<br>";
    } else {
        // check if email is a valid address in this format username@domain.com
        if(!ereg("[0-9a-z]([-_.]?[0-9a-z])*@[0-9a-z]([-.]?[0-9a-z])*\\.[a-z]", $_POST[email_input])) $error_msg.="Please enter a valid email address<br>";
    }

// display error message if any, if not, proceed to other processing
if($error_msg==''){//uncomment the line below to go to another page without using a header
//and change the done.php to whatever URL you need
//echo "<script type=\"text/javascript\">window.location=\"uploadT.php\"</script>";
} else {
    echo "<font color=red>$error_msg</font>";
}
}
?>

<form method="POST" action="simpleValid.php">
<table border="1" cellpadding="7" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" width="100%" id="AutoNumber1">
  <tr>
    <td width="16%" align="right">First Name</td>
    <td width="84%">
    <input type="text" name="first_name_input" size="20" value="<?php echo $_POST[first_name_input]; ?>"></td>
  </tr>
  <tr>
    <td width="16%" align="right">Last Name</td>
    <td width="84%">
    <input type="text" name="last_name_input" size="20" value="<?php echo $_POST[last_name_input]; ?>"></td>
  </tr>
  <tr>
    <td width="16%" align="right">Username</td>
    <td width="84%">
    <input type="text" name="username_input" size="20" value="<?php echo $_POST[username_input]; ?>"> (between
    6 to 15 characters)</td>
  </tr>
  <tr>
    <td width="16%" align="right">Password</td>
    <td width="84%">
    <input type="password" name="password_input" size="20" value="<?php echo $_POST[password_input]; ?>">
    (must be at least 4 characters)</td>
  </tr>
  <tr>
    <td width="16%" align="right">Email</td>
    <td width="84%">
    <input type="text" name="email_input" size="20" value="<?php echo $_POST[email_input]; ?>"></td>
  </tr>
  <tr>
    <td width="16%" align="right"> </td>
    <td width="84%">
    <input type="submit" value="   Register   " name="submit_button"></td>
  </tr>
</table>
</form>

</body>
</html>

korova

Thanks for the reply but I still couldn't get it working - could it be a caused by different versions of PHP? I'm using 5.1.2

Anyway, after playing around a bit I've finally got it working (I think!). For reference, here's the amended code:

<html>
<body>
<h3>PHP User Form</h3>
<?php
// only validate form when form is submitted

$first_name_input = '';
$last_name_input = '';
$username_input = '';
$password_input = '';
$email_input = '';

if(isset($_POST['submit_button'])){

$first_name_input = $_POST['first_name_input'];
$last_name_input = $_POST['last_name_input'];
$username_input = $_POST['username_input'];
$password_input = $_POST['password_input'];
$email_input = $_POST['email_input'];

$error_msg='';
if(trim($username_input)=='' || strlen(trim($username_input)) < 6 || strlen(trim($username_input)) > 15) {
    $error_msg.="Please enter a username between 6 to 15 characters long<br>";
}
if(trim($password_input)=='' || strlen(trim($password_input)) < 4) {
    $error_msg.="Please enter a password at least 4 characters long<br>";
}
if(trim($email_input)=='') {
    $error_msg.="Please enter an email<br>";
} else {
    // check if email is a valid address in this format [email]username@domain.com[/email]
    if(!ereg("[0-9a-z]([-_.]?[0-9a-z])*@[0-9a-z]([-.]?[0-9a-z])*\\.[a-z]", $email_input)) $error_msg.="Please enter a valid email address<br>";
}

// display error message if any, if not, proceed to other processing
if($error_msg==''){//uncomment the line below to go to another page without using a header
//and change the done.php to whatever URL you need
//echo "<script type=\"text/javascript\">window.location=\"InsertContactDetails3.php\"</script>"; 
} else {
    echo "<font color=red>$error_msg</font>";
}

}
?>

<form method="POST" action="form.php">
<table border="1" cellpadding="7" cellspacing="0" style="border-collapse: collapse" bordercolor="#111111" width="100%" id="AutoNumber1">
<tr>
<td width="16%" align="right">First Name</td>
<td width="84%">
<input type="text" name="first_name_input" size="20" value="<?php echo $first_name_input; ?>"></td>
</tr>
<tr>
<td width="16%" align="right">Last Name</td>
<td width="84%">
<input type="text" name="last_name_input" size="20" value="<?php echo $last_name_input; ?>"></td>
</tr>
<tr>
<td width="16%" align="right">Username</td>
<td width="84%">
<input type="text" name="username_input" size="20" value="<?php echo $username_input; ?>"> (between
6 to 15 characters)</td>
</tr>
<tr>
<td width="16%" align="right">Password</td>
<td width="84%">
<input type="password" name="password_input" size="20" value="<?php echo $password_input; ?>">
(must be at least 4 characters)</td>
</tr>
<tr>
<td width="16%" align="right">Email</td>
<td width="84%">
<input type="text" name="email_input" size="20" value="<?php echo $email_input; ?>"></td>
</tr>
<tr>
<td width="16%" align="right"> </td>
<td width="84%">
<input type="submit" value=" Register " name="submit_button"></td>
</tr>
</table>
</form>

</body>
</html>

Thanks for all your help.

Houdini

For future reference the problem you were having with the other code was that it was using 'short tags' <? and ?> instead of <?php and ?>. This means that the server you are using does not have the ability to use 'short tags' off. In this case the version of php does not matter so you will always have to use <?php inorder for PHP script to be recoginzed as such. I noticed that you gave the form values all an initail velue of blank (which really should not be necessary) butif that made it work then fine. The PHP part should not do anything until the submit button is pressed or clicked. Notice that the first condition of the PHP is to see if the value of the submit button is set meaning that it has actually been clicked and provide a value of 'submit_button' from the form then it checks for the fields username, password and email. It does not care if first or last name are entered, but you could make them required also by just checking if they are blank or not and if blank echo "Hey you did not enter your first or last name". Anyway glad you got it working then after you have it working to you satisfaction you need to uncomment the line and modify the URL to send the user to some other page when they have sucessfully filled out the form.

korova

Thanks, I didn't realise about turning on short tags, I'll do it on the server. I really don't understand why my setup is different from everyone elses so I have to initialise the variables as blank so that I don't get '</ br' in the text fields initially, but at least it's working now... I've amended the code to call a mysql function to insert data into a database and display a 'submitted' page when done - thanks for all your help I've spent days on this and now I can get on with the rest of the project :-)