Using `$this` in an anonymous function in PHP pre 5.4.0

Question

The PHP manual states

It is not possible to use $this from anonymous function before PHP 5.4.0

on the anonymous

Answer 1

Don't always rely on PHP to pass objects by reference, when you are assigning a reference itself, the behavior is not the same as in most OO languages where the original pointer is modified.

your example:

$CI = $this;
$callback = function () use ($CI) {
$CI->public_method();
};

should be:

$CI = $this;
$callback = function () use (&$CI) {
$CI->public_method();
};

NOTE THE REFERENCE "&" and $CI should be assigned after final calls on it has been done, again else you might have unpredictable output, in PHP accessing a reference is not always the same as accessing the original class - if that makes sense.

http://php.net/manual/en/language.references.pass.php