passing /retrieving data from jquery to php function - php

Question

I have actually read all related answers to my question but I need a clear and simple example on how to properly implement my code below.
myHome.php
jquery
var url = "computeArea.php";
var data = $('thisForm').serialize();
$.post(url,data,function(response)); // how do i get the area being returned from
computeArea function? i need to save the
return value to a javascript variable
computeArea.php
function computeArea ($data){ // do i need to parse $data to make it an array?
return $area;
}
im new to jquery and your help is very helpful. thank you!

Answer 1

You can do:
$.post(url,data,function(response){
alert(response)
});
ps: you are missing the . between $ and post.
In your php code you could do that:
echo json_encode($area);

Answer 2

Do a simple teste.
jQuery:
$.post("url/to/file.php",{variable_name: "hello"/*(we'll give this value to variable_name*/)},
function(response){
if(response>0)
alert('Something went wrong');
else
alert(response);
});
Now, on server side:
<?php
if(isset($_POST['variable_name']) && $_POST['variable_name']!=="")
echo $_POST['variable_name'];
else
echo 1;
?>

Answer 3

You are misunderstanding the use of post requests. This will not call the computeArea function in computeArea.php and pass data as its parameter:
var data = $('thisForm').serialize();
$.post(url,data,function(response));
You can do this instead for computeArea.php:
$data = $_POST['watever_you_are_serializing'];
// Do computations, etc.
$area = 123; // Contains computed area
echo $area; // Or json_encode($area);
If you need to call that function from computeArea.php, then you can create a new file for $.post request (eg. computeArea2.php) and include computeArea.php from there. It would be something like this:
include 'computeArea.php';
$data = $_POST['watever_you_are_serializing'];
echo computeArea($data);

Answer 4

Something along the lines of:
var url = "computeArea.php",
data = $('thisForm').serialize(),
new_variable;
$.post(url, data, function(response) {
new_variable = response;
});
Though I presume there's a bit more to your PHP script, as otherwise $area isn't defined anywhere.