Build a json in php from POST data - php

Question

I need to update a json list of object via url post data. For example, with url:
http://myweb.com/index.php?name=Peter&surname=Brown
in php, using get method:
$name = $_GET["name"];
$surname = $_GET["surname"];
$json = array();
$json["nombre"] = $name;
$json["lat"] = $lat;
$data[] = $json;
$json_end= json_encode($data);
and json_end efectively is done like I want:
[{"name":"Peter","surname":"Brown"}]
My question is about how I can do it incrementing the json, in order to build an array like:
[{"name":"Peter","surname":"Brown"}]
[{"name":"newname","surname":"newsurname"}]
// and so on
each time user use the url with new parameters.
Do I need to write to a file, or to database? Any tips will be apreciated.
The idea is to be able that any user can add some dat using url. I tried to store the json to a fiel but the storing is durable only along the current session.

Answer 1

<?
/* 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']);
This would produce a single JSON. However I don't know whether you meant to or not, but your output is a series of separate JSONs. You could do this by replacing the last line above with:
$json_string = '';
foreach($_SESSION['entries'] as $entry){
$json_string.= json_encode($entry) . "\n";
}
You would also probably want a way to reset/empty the array. In which case I'd change the if test from:
if(!array_key_exists('entries', $_SESSION))
to:
if(!array_key_exists('entries', $_SESSION) || array_key_exists('reset', $_GET))
Which you could use by visiting
http://myweb.com/index.php?reset
Edit: If somewhere you add the following code:
foreach($_SESSION['entries'] as $id=>$entry){
printf("%2d: %s\n", $id, json_encode($entry));
}
You'll get a list of the json elements enumerated by their respective keys. For example, it might look like:
0: "[{\"name\":\"Peter\",\"surname\":\"Brown\"}]"
1: "[{\"name\":\"newname\",\"surname\":\"newsurname\"}]"
2: "[{\"name\":\"George\",\"surname\":\"Washington\"}]"
3: "[{\"name\":\"John\",\"surname\":\"Adams\"}]"
If you then add the following code:
if(array_key_exists('del', $_GET) && is_numeric($_GET['del']))
{
$key = (int)$_GET['del'];
if(array_key_exists($key, $_SESSION['entries']))
{
unset($_SESSION['entries'][$key]);
}
else
{
printf('<strong>ERROR: $_GET['del'] = %d but $_SESSION['entries'][%d] doesn't exist.</strong>', $key, $key);
}
}
you'll be able to delete individual json entries by specifying id as the del GET parameter.
For example,
http://myweb.com/index.php?del=2
would delete the entry corresponding to '[{"name":"George","surname":"Washington"}]';
And the remaining entries would be:
0: "[{\"name\":\"Peter\",\"surname\":\"Brown\"}]"
1: "[{\"name\":\"newname\",\"surname\":\"newsurname\"}]"
3: "[{\"name\":\"John\",\"surname\":\"Adams\"}]"
4: "[{\"name\":\"Thomas\",\"surname\":\"Jefferson\"}]"

Answer 2

Just make a nested array of users:
$data = array (
0 => array("name"=>"Peter","surname"=>"Brown"),
1 => array("name"=>"newname","surname"=>"newsurname")
);
echo json_encode($data);
// [{"name":"Peter","surname":"Brown"},{"name":"newname","surname":"newsurname"}]

Answer 3

I think it would be easiest to store the data in a session, something like this:
<?php
session_start();
if (isset($_GET['name'])) {
$_SESSION['json'][] = $_GET;
}
echo json_encode($_SESSION['json']);
?>
Edit: You may want to filter the $_GET array before storing it in the session so that you don't store values that aren't meant to be stored.
Edit: Of course, if you want to save this data for more than one session you would need to use files or a database (or perhaps a cookie). It all depends on what you want to do with the information.