AJAX - The Complete Reference

Chapter 4: Data Formats 125

PART I

The benefit of this format is that everything on the server side is decoded automatically

just like a normal x-www-form-urlencoded submission, though now data is presented in

an array format as well. We provide a simple PHP example that echoes the received data in

this format.

<?php

header("Cache-Control: no-cache");

header("Pragma: no-cache");

echo "<strong>Payload</strong><div class='data'>";

$varList = "";

$varString = "";

/* $_POST can be used as well but $_REQUEST will include

cookies so be careful */

if (count($_GET) > 0)

{

echo "GET Query String: ";

echo $_SERVER['QUERY_STRING']. "<br /><br />";

printObjects($_GET);

echo "<br />";

}

echo "</div>";

function printObjects($obj, $indexString)

{

foreach($obj as $keyStr=>$val)

{

$key = $keyStr;

if (isset($indexString))

$key = $indexString. "[". $key. "]";

if (is_array($val))

printObjects($val, $key);

else

echo $key. "=". $val. "<br />";

}

}

?>

There is a limitation to this format in that it is not possible to have disassociated arrays

containing multiples objects. For example:

"stooge" : [{"name" : "Moe"}, {"leader" : true }]

would not work as expected. It forms the query string here:

stooge[][name]=Moe&stooge[][leader]=true

which then results in two occurrences of the stooge array rather than the nesting:

stooge[0][name]=Moe

stooge[1][leader]=true

This format is interesting, but if a more general object serialization is desired, it is better

to put data in JSON format as described later in the chapter.