Examples: One-way Cookie

Front End
Back End

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Chapter 2 : Cookie Rating - One Way</title>

<script type="text/javascript">

 
 
function sendRequest(url,payload)
{
    for (var key in payload)
    document.cookie = key+"="+payload[key]+"; path=/; domain=ajaxref.com";
 
    window.location = url;
}
 
function readCookie(name)
     {
       var nameEQ = name + "=";
       var ca = document.cookie.split(';');
       for (var i=0;i < ca.length;i++)
         {
          var c = ca[i];
          while (c.charAt(0)==' ')
              c = c.substring(1,c.length);
          if (c.indexOf(nameEQ) == 0)
              return c.substring(nameEQ.length,c.length);
         }
       return null;
      }
 
function rate(rating)
{
    /* string identifying type of example making rating */
    var transport = "cookie";
 
    /* URL of server-side program to record rating */
    var url = "http://ajaxref.com/ch2/setrating.php";
 
    /* form payload object with rating and transport name/value pairs */
    var payload = {'rating':rating, 'transport':transport};
 
    /* submit rating  */
    sendRequest(url,payload);
 
    /* indicate vote was made */
    var resultDiv = document.getElementById("resultDiv");
    var ratingForm = document.getElementById("ratingForm");
    ratingForm.style.display = "none";
    resultDiv.innerHTML = "Thank you for voting.  You rated this question a " + rating + ".  You can see the ratings in the <a href='http://ajaxref.com/ch2/ratings.txt' target='_blank'>ratings file</a>.";
    resultDiv.style.display = "";
}

</script>

 
</head>
<body>
<h3>How do you feel about JavaScript?</h3>
<form action="http://ajaxref.com/ch2/setrating.php" method="get" id="ratingForm">
<em>Hate It - </em> [
<input type="radio" name="rating" value="1" onclick="rate(this.value);" /> 1
<input type="radio" name="rating" value="2" onclick="rate(this.value);"  /> 2
<input type="radio" name="rating" value="3" onclick="rate(this.value);" /> 3
<input type="radio" name="rating" value="4" onclick="rate(this.value);" /> 4
<input type="radio" name="rating" value="5" onclick="rate(this.value);"  /> 5
] <em> - Love It</em>
<noscript>
 <input type="hidden" name="transport" value="downgrade" />
 <input type="submit" value="Vote" />
</noscript>
 
</form>
<br />
<div style="display:none;" id="resultDiv">&nbsp;</div>
</body>
</html>

view plain print

<?php
 
if (isset($_REQUEST["delay"]) && is_numeric($_REQUEST["delay"]))
    sleep($_REQUEST["delay"]);
 
/* File to write to */
$theFile = "ratings.txt";
$totalsFile = "totals.txt";
 
/* pull the user ratings via the query string */
$rating = htmlentities(substr(urldecode(gpc("rating")),0,1024));
$comment = htmlentities(substr(urldecode(gpc("comment")),0,1024));
$transport = htmlentities(substr(urldecode(gpc("transport")),0,1024));
$response = htmlentities(substr(urldecode(gpc("response")),0,1024));
$error = htmlentities(substr(urldecode(gpc("error")),0,1024));
$callback = htmlentities(substr(urldecode(gpc("callback")),0,1024));
 
if ($rating == "")
    $rating = 0;
 
if ($transport == "")
    $transport = "downgrade";
 
if ($response == "")
    $response = "none";
 
/* if error is set, set appropriate header and then return */
if ($error != "")
{
    if ($error == "404")
    header("HTTP/1.1 404 Not Found\n\n");
    else
    header("HTTP/1.1 500 Internal Server Error\n\n");
 
    exit;
}
 
 
/* record the IP address and time */
$userIP =  $_SERVER['REMOTE_ADDR'];;
$currentTime = date("M d y h:i:s A");
 
/* open the file and get the contents */
$filehandle = fopen($theFile, "r");
if ($filehandle)
{
    $data = fread($filehandle, filesize($theFile));
    fclose($filehandle);
}
else
   die('Failed to read file');
 
 
/* open the file and write line to the top of the file */    
$filehandle = fopen($theFile, "w+");
if ($filehandle) 
{
    fwrite($filehandle,"$rating\t $transport\t $userIP @ $currentTime\t $comment\n");
    fwrite($filehandle, $data);
    fclose($filehandle);
}
else
    die('Failed to write file');
 
//get the totals
$votes = $total = $average = 0;
$filehandle = fopen($totalsFile, "r+");
if ($filehandle) 
{
    $line = fgets($filehandle, 4096);
    $tokens = explode("\t", $line);
 
    if (count($tokens) > 1)
    {
        $votes = $tokens[0] + 1;
        $total = $tokens[1] + $rating;
    }
 
    fclose($filehandle);
}
else
    die('Failed to read file');
 
$filehandle = fopen($totalsFile, "w+");
if ($filehandle) 
{
    fwrite($filehandle,"$votes\t$total\n");
    fclose($filehandle);
}
else
    die('Failed to write file');
 
if ($votes != 0) $average = round(($total/$votes), 2);
 
// send the right headers
header("Cache-Control: no-cache");
header("Pragma: no-cache");
if ($transport != "downgrade")
{
    $message = "";
    if ($response == "none")
    {
        header("HTTP/1.1 204 No Content\n\n");
    exit;
    }
    else if ($response == "cookie")
    {
    $results = $rating . "a" . $average . "a" . $votes;
 
    //send an image back
    $filename = 'pixel.gif';
    $fp = fopen($filename, 'rb');
    header("Content-Type: image/gif");
    header("Content-Length: " . filesize($filename));
 
    //set the cookie
    setcookie("PollResults", $results, time()+3600, "/", "ajaxref.com");
 
    // dump the response image and end the script
    fpassthru($fp);
    exit;
    }
    else if ($response == "style")
    {
      $results = $rating . "a" . $average . "a" . $votes;
    $results = '==' . urlencode($results) . '==';
 
    header("Content-Type: text/css");
     echo
        "
            #divforajax
            {
                    background-image: url($results) ;
            }
        " ;
 
    exit;
    }
    else if ($response == "xml")
    {
    header("Content-Type: text/xml");
 
    echo
    "<?xml version=\"1.0\" encoding=\"UTF-8\" ?>\r\n
        <pollresults>\r\n
 
        <rating>$rating</rating>\r\n
        <average>$average</average>\r\n
        <votes>$votes</votes>\r\n
 
        </pollresults>\r\n
    " ;
 
    exit;
    }
    else if ($response == "JSON")
    {
    require_once('JSON.php');
       $json = new Services_JSON();
    $jsonResponse = new ResponseData();
    $jsonResponse->rating = $rating;
    $jsonResponse->votes = $votes;
        $jsonResponse->average = $average;
 
      $message = $json->encode($jsonResponse);
 
    }
    else if ($response == "script" && $callback != "")
    {
    $message = "";
     if ($transport != "script")
    {
           $message = "<script>";
            if ($transport == "iframe")
            $message .= "window.parent.";
    }
 
     $message .= "$callback('$rating','$votes','$average');";
 
    if ($transport != "script")
        $message .= "</script>";
    else
    {
        print $message;
        exit;
    }
    }
}
else
{
    $message = "Thank you for voting.  You rated this a <strong>$rating</strong>.  There are <strong>$votes</strong> total votes.  The average is <strong>$average</strong>.";
}
 
/* Helper functions */
function gpc($name)
{
    if (isset($_GET[$name]))
    return $_GET[$name];
    else if (isset($_POST[$name]))
    return $_POST[$name];
    else if (isset($_COOKIE[$name]))
    return $_COOKIE[$name];
    else
    return "";
}
 
 
class ResponseData
{
    public $average = 0;
    public $rating = 0;
    public $votes = 0;
    public $total = 0;
}
 
/*We'll only get to printing the html if we don't exit through one of the response codes */
?>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1" />
<title>Voting Results</title>
</head>
<body>
<?php echo $message ?>
</body>
</html>