I know this is something silly, but I can't figure it out. I found a few similar questions all in the context of an MVC framework. That's my case as well, as I am using CodeIgniter.
I have a file questions.php (that's included in a view):
require_once '../site_init.php';
var_dump($siteVars);
// shows null and a Notice: Undefined variable: siteVars
// but the ABSPATH constant is showing as defined!
var_dump(ABSPATH);
// shows string 'c:\wamp\www\sitename'
require '../site_init.php';
var_dump($siteVars);
// correctly dumps the content of siteVars array
and a file site_init.php that should be included everywhere as it holds my site-wide configuration values:
if ( !defined('ABSPATH') )
define('ABSPATH', dirname(__FILE__) . '/');
/** Site-wide sitevars */
$siteVars = array();
// set to true in develop environment
$siteVars['debug'] == false;
I know that The require_once statement is identical to require except PHP will check if the file has already been included, and if so, not include (require) it again however, when I am using require_once, I get a notice saying Undefined variable: siteVars, while using require, all works as expected. However, as you can see in the code above, the constant shows as defined, although they are both defined in the same file. PHP manual: Like superglobals, the scope of a constant is global. You can access constants anywhere in your script without regard to scope.
print_r(get_included_files()); shows site_init.php was included before the require_once, so I shouldn't have to require(_once) it again.
It must have something to do with variable scope. If I use global $siteVars, it works, without the need to require the file again, but can someone explain exactly why this happens? I am new to CodeIgniter. I can see there is only one entry point (the main index.php file) and that's the base file ($_SERVER['PHP_SELF']).
Ideally, I would also like to know how I can fix this without using global or require.
UPDATE: File structure seems to be the following (this is a project I am only working on, I am not the original developer):
controller welcome.php loads (include_once) a file X outside the CodeIgniter app folder structure (the CI app is the admin part of a larger site).
file X include_once site_init.php file
controller welcome.php loads the view $this->load->view('template', $data);
this is pretty much it. Hope this holds the key to a solution.
In CodeIgniter the only variables accessible in a view are passed to it from the controller. There should never be a reason to include anything in this way in COdeIgniter
Controller:
$d['title'] = 'title';
$this->load->view('main',$d);
View:
<?php print $title;?>
see Config Class http://www.codeigniter.com/user_guide/libraries/config.html for custom config values which could then be accessed in the controller and passed on to the view
This is a logical problem, the scope just helps you see it. Here's the key to it:
print_r(get_included_files());shows site_init.php was included before the require_once, so I shouldn't have to require(_once) it again.
This says that you've already included that file before, so require_once() doesn't do anything when you try it again. It's not that require_once() "doesn't load your variable", it just does what it should - avoid including a file that you've already loaded.
Obviously, require() doesn't care for that condition and it re-includes the script and hence imports the said variable in your current scope.
Anyway, including scripts again and again is a horrible method for getting data into your current scope. You should learn how to pass data around using function parameters.