Jquery Validation Remote Check Unique Not Working - php

Question

I wanted to post this online because I have been searching for days on this JQuery Remote validation issue. I cannot get it to work. I think my PHP code is correct as I have test the URL with a query in the URL and it returns false and true depending on with the recordset count is one or more
This is my Jquery Validate Code:
// validate form and submit
var $j = jQuery.noConflict();
$j(document).ready(function(){
$j("#myform").validate({
rules: {
ord_ref: {
required: true,
minlength: 12,
remote: "check_ord_ref.php"
},
messages: {
ord_ref: {
remote: "Order Number Does Not Exist"
}
}
}
});
});
This is my PHP code for the remote page "check_ord_ref.php"
$colname_rscheck_ord_ref = "-1";
if (isset($_GET['ord_ref'])) {
$colname_rscheck_ord_ref = (get_magic_quotes_gpc()) ? $_GET['ord_ref'] : addslashes($_GET['ord_ref']);
}
mysql_select_db($database_conn, $conn);
$query_rscheck_ord_ref = sprintf("SELECT ref_ord FROM orders WHERE ref_ord = '%s'", $colname_rscheck_ord_ref);
$rscheck_ord_ref = mysql_query($query_rscheck_ord_ref, $conn) or die(mysql_error());
$row_rscheck_ord_ref = mysql_fetch_assoc($rscheck_ord_ref);
$totalRows_rscheck_ord_ref = mysql_num_rows($rscheck_ord_ref);
if($totalRows_rscheck_ord_ref < 0){
$valid = 'false';
} else {
$valid = 'true';
}
echo $valid;
Please someone can you help solve the puzzle for myself and anyone else having issues
Using JQuery 1.5.2min
Validates OK without remote function

Answer 1

Ok, so I'm no PHP expert, but I do know that jQuery Validate expects the following result from a remote validation method:
The response is evaluated as JSON and must be true for valid elements,
and can be any false, undefined or null for invalid elements
Sending down "true" or "false" (note the quotation marks) is going to result in the value being parsed as the error message instead of being evaluated as a boolean primitive.
Back to the PHP part, I think you should probably use json_encode with a boolean primitive. I'm not quite sure the way to do this in PHP, but I believe it would be something like this:
$colname_rscheck_ord_ref = "-1";
if (isset($_GET['ord_ref'])) {
$colname_rscheck_ord_ref = (get_magic_quotes_gpc()) ? $_GET['ord_ref'] : addslashes($_GET['ord_ref']);
}
mysql_select_db($database_conn, $conn);
$query_rscheck_ord_ref = sprintf("SELECT ref_ord FROM orders WHERE ref_ord = '%s'", $colname_rscheck_ord_ref);
$rscheck_ord_ref = mysql_query($query_rscheck_ord_ref, $conn) or die(mysql_error());
$row_rscheck_ord_ref = mysql_fetch_assoc($rscheck_ord_ref);
$totalRows_rscheck_ord_ref = mysql_num_rows($rscheck_ord_ref);
if($totalRows_rscheck_ord_ref < 0){
$valid = false; // <-- Note the use of a boolean primitive.
} else {
$valid = true;
}
echo json_encode($valid);

Answer 2

This problem seems to be plaguing remote validation scripters and the jQuery documentation on the matter is clearly lacking.
I notice you are using jQuery 1.5.2: from what I understand (and found from experience) you must use the jQuery callback that is sent to the remote script with $_REQUEST with versions after 1.4, AND jQuery is expecting "true" or "false" as a STRING. Here is an example, confirmed working on multiple forms (I'm using jQuery 1.7.1):
if($totalRows_rscheck_ord_ref < 0){
header('Content-type: application/json');
$valid = 'false'; // <---yes, Validate is expecting a string
$result = $_REQUEST['callback'].'('.$check.')';
echo $result;
} else {
header('Content-type: application/json');
$valid = 'true'; // <---yes, Validate is expecting a string
$result = $_REQUEST['callback'].'('.$check.')';
echo $result;
}
I found this answer here (in the answers section), randomly, and have since stopped pulling out my hair. Hope this helps someone.

Answer 3

To add to Andrew Whitaker's response above, I must stress that you are sure that the response is strictly JSON and that there are no other content types being returned. I was having the same issue with my script, and everything appeared to be set properly - including using json_encode(). After some troubleshooting with Firebug's NET tab, I was able to determine that PHP notices were being sent back to the browser converting the data from JSON to text/html. After I turned the errors off, all was well.

Answer 4

//check_validate.php
<?php
// some logic here
echo json_encode(true);
?>