AJAX, JSON, jQuery, and PHP - php

Question

I know there are alot of different questions about this but none of them seem to pertain to me. I have an ajax request as follows:
var responsePacket;
$.ajax({
dataType: 'json',
type:'POST',
data:{
"updatePacket":{
"job":"name-update",
"firstName":firstName,
"lastName":lastName
}
},
processData: false,
url:'modify.php',
success: function(json){
console.log(json);
responsePacket = json;
if(responsePacket.updateStatus==true){
genAlertAlignAndShow('Name Successfully Updated', false, 4000);
}
else{
genErrorAlignAndShow('Name Update Failed!', false, 4000);
}
}
})
And my PHP on the other end are as follows:
$updatePacket = json_decode($_POST['updatePacket'], true);
//and I access variables from the JSON Object like this:
$job = $updatePacket['job'];
In response to the AJAX, the PHP file will punch out a simple JSON object, and yes my headers are set to application/json. This is how I a output a JSON response, I have tested it and it appears to get back to the AJAX Request when I rig it to return a static response:
$responsePacket = array("updateStatus"=>true);
echo json_encode($responsePacket);
But Here Is The Problem
As you can see I output the data to the console, but all it says is null which I have deduced is indicative of the JSON not getting to the PHP correctly. So, is there a proper way to create JSON Objects and prepare an AJAX request that will get the data to the PHP script intact.
I have been grappling with this problem for about 3 hours now, ANY suggestions are welcome.

Answer 1

I believe $_POST['updatePacket'] is not actually a json string. Try to access it like this instead:
$updatePacket = $_POST['updatePacket'];
$job = $updatePacket['job'];
No need to json_decode() it. From the json_decode() manual (return value):
NULL is returned if the json cannot be decoded...
Give it a try. As mentioned in the comments, var_dump($_POST); should be the first thing you try, to ensure you're getting what you think you are.

Answer 2

I figured it out. Here is my AJAX Requst:
$.post('modify.php', { job: "name-update", lastName: lastName }, function(data){
console.log(data);
})
The Problem:
When declaring data for an AJAX Post request putting quotes on the variable names will make the variables inaccessible to the receiving script.

Answer 3

You can easily make the time consuming issue of getting form data in a clean way with jquery, or javascript alone.
All you need to do is .serialize() the data. An example is here.
$( "form" ).on( "submit", function( event ) {
event.preventDefault();
console.log( $( this ).serialize() );
});
Once it is done you can transform a string that looks like this.
"param1=someVal&param2=someOtherVal"
with this
$params = array();
parse_str($_GET, $params);
with this usage you also want to filter the data and you should do this prior to the above.
http://php.net/manual/en/function.filter-input.php
Do this is less time consuming then listing each one individually in your ajax. You can also create a function to do this so you aren't continually writing ajax boilerplate code.

Answer 4

You are doing it wrong. You don't send a JSON object to the server, you send key/value pairs. And it's what jQuery expects. Do it like this instead:
data: {
"job": "name-update",
"firstName": firstName,
"lastName": lastName
},
and access the values like this:
$job = $_POST['job'];