Form Processing - variables passed as POST from one page to the next

Simon_Hartley

I have written code for a calculator which works out the %specimen weight for a given fish! Users input the species and weight and submit the form using POST to a results page where the calculation is made and the results are displayed. All is working fine.

However I would like to include error checking on the form page so if say a weight is not input by the user a warning is displayed on that same page.

To include error checking on the same page as the form then the form data will need to be submitted to the samepage its on.. no problem.

What I need to know is how do I then pass the variables from the form to the results page once the error checking is completed and there are no errors. I would like to send by POST and not rely on cookies or GET to send the variables to the results page for calculation.

Many thanks to all who consider my question.

devinemke

you can either put the data in hidden form fields or you can store them in a session.

Simon_Hartley

Thanks Devinemke

Following your advice, I will look into using a hidden form to send the data via post once error checking is complete.

Simon_Hartley

Since the last response I've read over a few tutorials and understand how to send variables from one page to another using hidden fields. However I can't work out how to send variables in hidden fields after running code on the same page first..

For example in the simple code below the form calls the same page to check whether the name variable has been set. If it hasn't a warning message is given just below the text field on the form.

If the variable has been set how would I then pass this variable ($_POST['name'] to another page using a hidden form after this error checking.

<?php
if (isset($_POST["submit"]) && ($_POST['name'] == "")){
$warning = "<h3>oops please type your name</h3>";
}
else $warning = "";
?>
<html> 
<head> 
</head> 
<body> 
<p>Please fill in the following information</p> 
<form method="post" action="page1.php"> 
Name: <input type="text" size="40" name="name"><br> 
<?php echo $warning; ?>
<input type="submit" name="submit" value="Submit"> 
</form> 
</body> 
</html>

devinemke

a simple example:

<?php
function form()
{
	if (isset($_POST['name'])) {$name = $_POST['name'];}
	else {$name = '';}

echo '
<form action="" method="POST">
<input type="text" name="name" value="' . $name . '"><br>
<input type="submit" name="submit" value="submit">
</form>
';
}

if (!isset($_POST['submit']))
{
	form();
}

if (isset($_POST['submit']) && $_POST['submit'] == 'submit')
{
	if ($_POST['name'] == '')
	{
		echo 'you forgot to fill in your name<br>';
		form();
	}
	else
	{
		echo '
		you entered ' . $_POST['name'] . '.  if this is correct press <b>continue</b>.  if not please re-enter your name and press <b>submit</b>
		<form action="" method="POST">
		<input type="hidden" name="name" value="' . htmlspecialchars($_POST['name']) . '">
		<input type="submit" name="submit" value="continue">
		</form>
		<br>
		<br>
		';

	form();
}
}

if (isset($_POST['submit']) && $_POST['submit'] == 'continue')
{
	echo 'thank you ' . $_POST['name'];
}
?>

Simon_Hartley

Thanks again Devinemke

Would there be a way to use this method to automatically forward the details on without the user having to press the continue button once the error checking is complete?