PHP $_GET with Ajax/Jquery Request
Question
I am trying to set a variable $id=$_GET["categoryID"]. I cannot get it to work. I believe it has to do with the the Ajax request. But I don't know how I have to format it so that it will work in conjunction with that request. I need the variable for a mysql query. Any help is greatly appreciated. This is over my head and have been struggling with it for days. I have tried both GET and POST. Thanks.
I have distilled the page down to this...
<!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>Test $_GET</title>
</head>
<body>
<?php
if(isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest') {
$id = $_GET["categoryID"];
//$id=3;
}
?>
print_r($_GET) = <?php print_r($_GET); ?>
<br />
print_r($id) = <?php print_r($id); ?>
</body>
</html>
Here is the resulting page....
<!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>Test $_GET</title>
</head>
<body>
print_r($_GET) = Array
(
[categoryID] => 1001
)
<br />
print_r($id) =
</body>
</html>
Here is the whole page....
<?php
if (@$_REQUEST['ajax']) {
$link = $nm33;
if ($link == false)
trigger_error('Connect failed - ' . mysql_error(), E_USER_ERROR);
$connected = mysql_select_db('nm', $link);
if ($connected) {
//How do I set $id = $_GET["categoryID"] It fails to set the variable.
$id =$_GET["categoryID"];
// $id=1;
// It will work as $id=1
$results = mysql_query('select * from selectMenu where categoryID= \'' . $id . '\' AND category="' . strtolower(mysql_real_escape_string(strip_tags($_REQUEST['category']))) . '"');
//////////
$json = array();
while (is_resource($results) && $row = mysql_fetch_object($results)) {
//$json[] = '{"id" : "' . $row->id . '", "label" : "' . $row->label . '"}';
$json[] = '"' . $row->label . '"';
}
echo '[' . implode(',', $json) . ']';
die(); // filthy exit, but does fine for our example.
} else {
user_error("Failed to select the database");
}
}
?>
<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>
<script src="js/select-chain.js" type="text/javascript" charset="utf-8"></script>
<script type="text/javascript">
<!--
$(function () {
var cat = $('#categorySelect');
var el = $('#elementSelect');
var attr = $('#attributeSelect');
el.selectChain({
target: attr,
url: 'select-menu.php',
data: { ajax: true, anotherval: "anotherAction" }
});
// note that we're assigning in reverse order
// to allow the chaining change trigger to work
cat.selectChain({
target: el,
url: 'select-menu.php',
data: { ajax: true }
}).trigger('change');
});
//-->
</script>
<link href="selectMenu.css" rel="stylesheet" type="text/css" />
<form action="performance-models.php" method="get">
<select name="category" class="dropdown" id="categorySelect">
<option selected="selected">Select Your Vehicle</option>
<?php do { ?>
<option> <?php echo $row_rsMake['make']; ?></option>
<?php } while ($row_rsMake = mysql_fetch_assoc($rsMake)); ?>
</select>
<select name="model" class="dropdown" id="elementSelect">
<option selected="selected">Select Model</option>
<option>[none selected]</option>
</select>
<select name="appYear" class="dropdown" id="attributeSelect" >
<option selected="selected"> </option>
<option>[none selected]</option>
</select>
<input type="submit" value="Go">
</form>
<p><br />
<br />
print_r($_GET) = <?php print_r($_GET); ?> <br />
print_r($_REQUEST) = <?php print_r($_REQUEST); ?><br />
echo $_REQUEST['categoryID'] <?php echo $_REQUEST['categoryID'];?>
</p>
Here is select-chain.js
(function ($) {
$.fn.selectChain = function (options) {
var defaults = {
key: "id",
value: "label"
};
var settings = $.extend({}, defaults, options);
if (!(settings.target instanceof $)) settings.target = $(settings.target);
return this.each(function () {
var $$ = $(this);
$$.change(function () {
var data = null;
if (typeof settings.data == 'string') {
data = settings.data + '&' + this.name + '=' + $$.val();
} else if (typeof settings.data == 'object') {
data = settings.data;
data['category'] = $$.val();
data['model'] = $$.val();
data['year'] = $$.val();
}
settings.target.empty();
$.ajax({
url: settings.url,
data: data,
type: (settings.type || 'get'),
dataType: 'json',
success: function (j) {
var options = [], i = 0, o = null;
for (i = 0; i < j.length; i++) {
// required to get around IE bug (http://support.microsoft.com/?scid=kb%3Ben-us%3B276228)
o = document.createElement("OPTION");
o.value = typeof j[i] == 'object' ? j[i][settings.key] : j[i];
o.text = typeof j[i] == 'object' ? j[i][settings.value] : j[i];
settings.target.get(0).options[i] = o;
}
// hand control back to browser for a moment
setTimeout(function () {
settings.target
.find('option:first')
.attr('selected', 'selected')
.parent('select')
.trigger('change');
}, 0);
},
error: function (xhr, desc, er) {
// add whatever debug you want here.
alert("an error occurred here");
}
});
});
});
};
})(jQuery);
4 answers
solution1
3 2012-05-10 17:17:36
A $_GET parameter is passed in the URL so for this;
The parameter $_GET['q'] would be equal to 'search'
So when you perform your AJAX request you need to specify the parameters in the URL.
EDIT :
Try getting rid of your HTTP_X_REQUESTED_WITH statements. The request is probably safe enough without those kind of checks. Just simplify it to:
if ( isset( $_GET["categoryID"] ) ) {
$id = $_GET["categoryID"];
}
solution2
1 2012-05-10 17:31:16
There is no need for:
if(isset($_SERVER['HTTP_X_REQUESTED_WITH']) && strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) == 'xmlhttprequest')
You can just use:
$id = isset($_GET["categoryID"]) ? intval($_GET["categoryID"]) : 0;
Which is the same as (but shorter...):
if (isset($_GET["categoryID"]))
{
$id = intval($_GET["categoryID"]);
}
else
{
$id = 0;
}
If you want to check if a request was made via ajax, you would have to rewrite your script as the whole header section would not be needed. Instead you could call this script from your page, set a variable in the page itself and if that variable is not set in the script, it's an ajax call. Obviously this is just a simple example.
Edit: The plugin does not mention what the default type of the request is, but that could very well be POST so you could try to add type: "post" to the options of selectChain .
And to make sure that your response is well-formed json (when you get there...) I would also recommend you use json_encode , so:
echo json_encode($json);
die(); // filthy exit, but does fine for our example.
Edit 2: I just noticed another problem: Nowhere is the categoryID being added to the data section in the ajax:
- You are requesting / posting to (???) :
select-menu.php(notice, no query string!) - The data you are sending is:
{ ajax: true, anotherval: "anotherAction" }or{ ajax: true}
So there is no way that categoryID is ever going to show up in select-menu.php .
The most logical thing to do, would be to add the selected category to the data section:
data: { "ajax": true, "anotherval": "anotherAction", "categoryID": cat }
and:
data: { "ajax": true, "categoryID": cat }
solution3
0 2012-05-10 17:24:41
With jQuery you can use jQuery.get() or add a type='GET' parameter to jQuery.ajax() . Some example:
jQuery(function($) {
$.ajax({
url : 'your-page.php',
type : 'GET',
data : {
'paramName' => 'paramValue',
'foo' => 'bar'
},
success : function(data) {
// do something in the callback function
}
});
});
solution4
0 2012-05-10 17:25:42
You need to pass the value in the jQuery.get() :
$.get('yourphppage.php', { categoryID : 1234 }, function(data) {
alert(data);
});
In your php just echo right back your cateogryId to see if it is working
<?php echo $_GET['categorID'] ?>
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