PHP variable scoping - php

Question

I'm having some trouble with variable scoping in PHP. Here's the structure of my code--
<?php
$loader = new ELLoad();
$sessionid = '';
$method = $_REQUEST['m'];
if (strcasecmp($method, "getfile") == 0) {
global $loader;
$loader->load($file['text']);
global $sessionid;
$sessionid = $loader->getSessionId();
}
if (strcasecmp($method, "extract") == 0) {
$extractor = new ELExtract();
global $sessionid;
$extractor->extract($sessionid); //$session id for some reason is still ' ' here
}
The sequence of the requests from the client is always load followed by extract. Can anyone tell me why my $sessionid variable may not be getting updated right?

Answer 1

$sessionid is still '', because It's not change if first condition == false
Improvement of your code:
$loader = new ELLoad();
$sessionid = $loader->getSessionId();
$method = $_REQUEST['m'];
if (strcasecmp($method, "getfile") == 0) {
$loader->load($file['text']);
// do more stuff
}
else if (strcasecmp($method, "extract") == 0) {
$extractor = new ELExtract();
$extractor->extract($sessionid);
// do more stuff
}
Also It's better to use $_GET or $_POST depend on your case, instead of $_REQUEST and finally using else if in separate and repeated conditions.

Answer 2

You don't have to declared global $... unless you're in a function. A block (if, while, ...) have the same scope than the line just before.
I don't know what you want to do, but you have to keep you $sessionid content in a real session, like:
<?php
session_start();
$loader = new ELLoad();
$_SESSION['id'] = '';
$method = $_REQUEST['m'];
if (strcasecmp($method, "getfile") == 0) {
$loader->load($file['text']);
$_SESSION['id'] = $loader->getSessionId();
}
if (strcasecmp($method, "extract") == 0) {
$extractor = new ELExtract();
$extractor->extract($_SESSION['id']); //$session id for some reason is still ' ' here
}