Clearing POST data

asa_carter

How do I clear POST data once a page is loaded?

If I use the back button from the next page, this page tries to reload the POST data. It should just clear all the fields as if it was loading for the first time.

<?
session_start();
$_SESSION["thisurl"] = $_SERVER['REQUEST_URI'];
$valid_user = $_SESSION["valid_user"];
if ($_POST["sent"]) $sent = $_POST["sent"];
if ($_POST["title"]) $title = $_POST["title"];
if ($_POST["type"]) $type = $_POST["type"];
$doc_title = "Property";
include("connect.php");

if ($sent == true) {

  if (!$title)
    $err1 = true;

  if ($err1 == false) {
    $new_property_result = mysql_query("INSERT INTO property VALUES ('', '$valid_user', '$title', '$type')");
    $_SESSION["property_id"] = mysql_insert_id();
    header("location: property_maintain.php");
    exit;
  }
}

include("get_user.php");
include("header.php");
include("navigation.php");
include("user_validate.php");
?>
<div id="content_wrap">
 <div id="left_bar">
  <div id="logo" title="Logo"></div>
  <? include("user.php"); ?>
 </div>
 <div id="right_bar">
  <div id="property_add">
   <div class="title">Create New Property Listing</div>
   <div style="padding:20px;">
    <?
    if ($err1 == true)
	  echo "<div class=\"error_dialog\" style=\"display:block;\">Please enter a name for this listing</div>";
	?>
    <form action="property_add.php" method="post">
    <input type="hidden" name="sent" value="true" />
    <label>What would you like to call this property listing?</label>
    <div class="input_container">
     <div><input type="text" class="inputtext" style="width:300px;" name="title" /></div>
    </div>
    <label>What would you like to do?</label>
    <div class="input_container">
     <div id="r1" style="background-color:#D8DFEA;padding:10px;cursor:pointer;">
      <input type="radio" name="type" id="f1" value="sale" checked="checked" /> I would like to sell a property.
     </div>
     <div id="r2" style="padding:10px;cursor:pointer;">
      <input type="radio" name="type" id="f2" value="rent" /> I would like to let a property.
     </div>
     <div id="r3" style="padding:10px;cursor:pointer;">
      <input type="radio" name="type" id="f3" value="wanted" /> I am looking for a property to buy or rent.
     </div>

</div>
<input type="submit" class="button" name="1" value="Create Listing" />
</form>
   </div>
  </div>
 <div class="clearfix"></div>
</div>
<? include("footer.php"); ?>

NogDog

The most common solution is to do a header() location redirect, which will clear the post data cache. You could redirect to the same page but with a query string flag of some sort to let you know this is the result of a successful form submission.

// process form, then (before anything is output to browser:
header("Location: http://www.example.com".$_SERVER['SCRIPT_NAME']."?success=1");
exit();

// elsewhere on the page where you output your HTML:
if(!empty($_GET['success']))
{
   echo "<p>Thank you. Your request has been successfully submitted.</p>\n";
}

asa_carter

Yeh, I am redirecting as in the above code.

There is no problem if I enter a title and continue to the next page. If I use the back button on the redirected page, the page reloads without prompting to revalidate.

However, If I do not enter a title, the same page reloads. If I then enter a title and redirect to the next page.. and then use the back button, I am prompted to reload the page.

I've just looked at some popular sites and found that users are asked to reload the page on using the back button but to me it looks unprofessional and could be confusing to a new user.