Help! - Cannot access a global variable.
Suppose you have the following module. To your dismay, the value of the variable you think is global is not accessible:
$myvar = 'foo';
function example_something() {
global $myvar;
return $myvar; // returns NULL
}
Cause
From http://www.php.net/manual/en/function.include.php
When a file is included, the code it contains inherits the variable scope of the line on which the include occurs.
As module files are loaded by drupal_load, it follows that $myvar is a variable declared in the local scope of the function drupal_load.
Solution
Use the global keyword or $GLOBALS superglobal.
// Declare and initialize $myvar as an explicit global:
global $myvar;
$myvar = 'foo';
// Or use the superglobal:
$GLOBALS['myvar'] = 'foo';
function example_something() {
global $myvar;
return $myvar; // returns 'foo'
}