POST data to permanent json file using PHP - php

Question

using a url, my idea is that any user can post data. For example via
http://myweb.com/index.php?name=Peter&surname=Brown
Using the "jedwards" answer, present here, I am able to create a json and save it to a file.
<?
/* This needs to be at the top of your file, without ANYTHING above it */
session_start();
/* ... */
if(!array_key_exists('entries', $_SESSION))
{
$_SESSION['entries'] = array();
}
$_SESSION['entries'][] = array("name" => $_GET["name"], "surname" => $_GET["surname"]);
$json_string = json_encode($_SESSION['entries']);
My problem is that this is not permanent amongst different session or user. It works only on the same session. On different session the json built start from the beginning.

Answer 1

First of all, don't use GET requests to change the state of the server. GET is only supposed to read (or.. um.. GET) data from the server.
In order to change data, use POST. It's more fitted, slightly more secure, and is great when transferring larger amounts of data.
Now, for the problem at hand. For a more permenant solution, the best option is to enforce user registration, and save the required data on a database, with a reference to the user's ID.

Answer 2

Yes because sessions, as the name imply, are only temporary (and sort of local). When the browser is closed it's gone. Depending on what your demands are you'll have to choose between using a database or textfiles on the server.
Cookies or sessions is not made for this kind of data.

Answer 3

Well if you are looking for a rudimentary solution, see below. If not, use a database as suggested in the other answers.
<?
/* This needs to be at the top of your file, without ANYTHING above it */
session_start();
/* ... */
$file = sys_get_temp_dir() . '/entries.json';
$data = file_get_contents($file);
$entries = (!empty($data)) ? json_decode($data) : array();
$entries[] = array("name" => $_GET["name"], "surname" => $_GET["surname"]);
file_put_contents($file,json_encode($entries),FILE_APPEND);