Prototype framework and JSON AJAX problem

JavaScript
1

I’m trying to make an AJAX request to my localhost server. Here is the code for the page that is requested, ajaxresponsecontent.php. The content is queried from a MySQL database then encoded into JSON using PHP.


<!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=utf-8" />
<title>Untitled Document</title>
<script type="text/javascript" src="../javascript/prototype.js"></script>
<?php  

    @ $db = mysqli_connect('localhost', 'root', '', 'mealchamp');

	$query = "SELECT * FROM globalfood WHERE foodid = 1";
	$result = mysqli_query($db, $query);
	$row = mysqli_fetch_assoc($result);

	$reqVar = json_encode($row);
	$reqVar = "'" . $reqVar . "'";
	echo $reqVar;

?>
</head>
<body>
</body>
</html>

The output of the content page when run in a browser is serialized JSON:

‘{“foodid”:“1”,“food”:“Mozzarella cheese”,“brand”:“Black Diamond”,“ftype”:“Dairy & Alternatives”,“servamt”:“1\/4 inch cube”,“ss”:“30.0”,“cal”:“110.0”,“fat”:“8.0”,“sat”:“5.0”,“trans”:“0.2”,“chol”:“25.0”,“sod”:“230.0”,“carb”:“1.0”,“fib”:“0.0”,“sug”:“0.0”,“pro”:“8.0”}’

The second page, ajaxresponsecaller.php, makes an ajax request for this previous page using the Prototype framework. the code for the requesting page is:


<!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=utf-8" />
<title>Untitled Document</title>
<script type="text/javascript" src="../javascript/prototype.js"></script>
<script type="text/javascript"><!--

new Ajax.Request('ajaxrequestcontent.php',
  {
    method:'get',
    onSuccess: function(transport){
      var response = transport.responseText || "no response text";
			document.write(response);
			var try1 = response.evalJSON();
			document.write(try1.food);
    },
    onFailure: function(){ alert('Something went wrong...') }
  });

--></script>
</head>
<body>
</body>
</html>

The PROBLEM is that the document.write(response) works fine in that it outputs the JSON string just how its supposed to be, same output as i showed above for the previous page. but when i try to use Prototypes’ evalJSON to convert it to an object, something is going wrong. document.write(try1.food); gives no output.

What am i doing wrong exactly? could u provide an example? been working at this for hours can’t figure out the problem.

Thanks so much, G

2

It looks like the ajaxrequestcontent.php page is also outputting HTML content. It should not be outputting any HTML content. It should only output JSON code.

3

i’m running this script on my testing server on local machine. From what i can tell get magic quotes it not turned on (code below is used to checK)


if(get_magic_quotes_gpc())
	echo "Magic quotes are enabled";
else
	echo "Magic quotes are disabled";

Anyways i use addslashes to escape apostraphes and slashes before inserting them into a mySQL database. However, when i try to unescape them using stripslashes, it doesnt seem to be having an effect.

the following is a snippet of code that acts on a MySQL query result. I’m attempting to stripslashes but it’s not working. When this query string is passed back to Javascript via Ajax, some things are still escaped when i output the JSON string to an alert box. For example, i call addslashes before inserting 1/2 into database, when i retrieve it through ajax via this script and use stripslashes, in an alert box it is still appearing as “1\/2”.


	if ( $returnVar->select == "yes" ) {
		$arr = NULL;

		if ($result)
			$num_results = mysqli_num_rows($result);
		else
			$num_results = 0;

		for ($i = 0; $i < $num_results; $i++) {
			$row = mysqli_fetch_assoc($result);
			foreach ( $row as $current ) {
				$current = stripslashes($current);
			}
			$arr[$i] = $row;
		} 
		$returnVar->items = $num_results;
		

	}

$z = rawurlencode(json_encode($returnVar));
echo $z;

i then retrieve $z using AJAX call.

Also, the string " Honey Nut O’s Cereal " is successfully inserted into database after calling addslashes on it. when its retrieved via the above snippet and output to a table cell in Html using JS, it appears the slash is gone. It also appears gone if i call an alert box on AJAX response string (but slash is sitll present in “1\/2” which i cannot figure out.) But when i then take the value from the table cell ( by using innerHTML ) and try to insert it back into the database, after calling addslashes it goes from having 0 slashes to 2 slashes!! wtf pls help cannot figure this out.