form validation without reset

Question

Hi guys

Is there a way to check the data sent by a form to a PHP page return to the form page WITHOUT resetting the data sent and show a error?

The form has 20 fields and I need to check one of them on a bd. If it fails the user may be redirected to the form page with the form populated and displaying a error message on the field which is 'wrong'.

I would like any advice of a technique instead of populating each field using PHP.

UPDATE:

I do not want to use any solution that involves repopulate the fields by myself!!!

I want a solution that return to the form page populated with the previous values. I've tried something like js.history.back or window.back(). But the form returns empty...

Answer 1

Yeah, just check the forms beforehand, make sure you run the form HTML after the validation procedure, and if validation fails, reload the form with all of the prior information in the fields.

It might look something like this:

<?php if(isset($_POST['submit']){
    // validation code goes here with a trigger variable to
    // contain true or false depending on the outcome    
}

if($trigger==false){
    // load up your post data here    
} 

echo '
    <!-- form HTML goes here -->
';

Answer 2

In your form fields HTML, add posted values as field value.

e.g:

<input type='text' name='email' value='<?php echo $_POST['email']; ?>' />

Answer 3

On your Form Validation page

<?php
$form_values = $_POST;
//Your Form Validation
//$form_validated = TRUE/FALSE;  // FALSE if there were errors

if ($form_validated) {$form_values = array();}
$_SESSION['form_values'] = $form_values; /* if your form validation page and form page is not on the same page and can also use the same technique for error messages */
?>

On your Form page for each input field.

<?php
$form_values = $_SESSION['form_values']; //if your form validation page and form page is not on the same page
unset($_SESSION['form_values']);

echo '<input type="text" name="user_name" value="'.$form_values['user_name'].'" />';
?>

Different input types will need to handle the $form_values array differently but this should get your started.

If you are not using a seperate form validation page, you can get the form values directly form the $_POST array.