Serialized AJAX $_POST is not empty but single $_REQUEST is empty - php

Question

I'm making an AJAX Call like this:
$( "#submit_jobs_preview" ).click(function(e) {
var postData = $('#new_job_form').serialize();
var formURL = "ajax.xxx.php";
$.ajax({
type: 'POST',
url: formURL,
data: {submit_jobs_preview: postData },
success: function(data){
alert(data);
}
});
e.preventDefault(); //STOP default actio
});
In php i echo:
echo $_POST['submit_jobs_preview'];
This $_POST shows all values i put in my form correctly like this:
new_job_city=Berlin&new_job_name=Manager etc.
But if i want a single $_REQUEST from this $_POST like this:
if($_POST['submit_jobs_preview']){
echo $city = mysql_real_escape_string($_REQUEST['new_job_city']);
}
the alert is empty.
Why is that?
UPDATE
Full return of data:
XHR Loaded (autocomplete.php - 200 OK - 105.99994659423828ms - 354B) VM2106:3
new_job_city=Halle&new_job_job=Flugbegleiter&new_job_other_job=&job_zielgruppe=Auszubildende&new_job_phone=4921663965439&new_job_email=kleefeld%40dsc-medien.de&new_job_detailhead=F%C3%BCr+unser+zentrales+Marketing+mit+Sitz+in+der+Hauptverwaltung+in+der+City+von+D%C3%BCsseldorf+suchen+wir+zum+n%C3%A4chstm%C3%B6glichen+Termin+eine%2Fn&new_job_time=Vollzeit&teilzeit_std=&new_job_tasks=&new_job_profile=&new_job_advantage=&new_job_creatorId=1&new_job_creationDate=1390569795&new_job_scope=Airport+Service&new_job_niederlassung=7&new_job_active=0

Answer 1

You don't need to use {submit_jobs_preview: postData } if it is not necessary. I will give you another hint. Use following ajax;
$( "#submit_jobs_preview" ).click(function(e) {
var postData = $('#new_job_form').serialize();
var formURL = "ajax.xxx.php";
$.ajax({
type: 'POST',
url: formURL,
data: postData,
success: function(data){
alert(data);
}
});
e.preventDefault(); //STOP default actio
});
and on php side;
if($_POST['new_job_city']){
echo $city = mysql_real_escape_string($_REQUEST['new_job_city']);
}
In this case you can use field names directly.
Another hint:
You can put a hidden value on your form like,
<input type="hidden" name="submit_jobs_preview" value="true"/>
and js side will be same as above in my answer, and in php side you can check like;
if($_POST['submit_jobs_preview']){
echo $city = mysql_real_escape_string($_REQUEST['new_job_city']);
}
As you can see, you can send your post value as hidden field and make your check

Answer 2

$_POST['submit_jobs_preview'] holds a string and nothing else so you just can't access it that way. Use parse_str() to unserialize $_POST['submit_jobs_preview']. That way you can access its properties.
$_POST['submit_jobs_preview']['new_job_city']