Cannot make non static method - FATAL ERROR - php

Question

I was working on a PHP web application. I used a new datagrid from gurrido.net and it worked well on the local but when I upload it to the server, I get the following error:
Fatal error: Cannot make non static method Base::getClassName() static
in class Singletons in /var/www/reskb/phpinc/Singletons.class.php on
line 84
In my old version where I didn't use the grid, I got it working. Here is my code of singletons.class.php file:
<?
class Singletons extends Base {
var $objects = array();
function getClassName() {
return 'Singletons';
}
function _instance() {
static $_instance = NULL;
if ($_instance == NULL) {
$className = Singletons::getClassName();
$_instance = new $className();
}
return $_instance;
}
function put($object) {
$self = Singletons::_instance();
$className = $object->getClassName();
$self->objects[$className] = $object;
}
function get($className) {
$self = Singletons::_instance();
if(!empty($self->objects[$className]))
return $self->objects[$className];
else return '';
}
}
Singletons::_instance();
?>

Answer 1

You should call function getClassName using object or define getClassName as static. –
<?php
class Singletons extends Base {
var $objects = array();
static function getClassName() {
return 'Singletons';
}
static function _instance() {
static $_instance = NULL;
if ($_instance == NULL) {
$className = Singletons::getClassName();
$_instance = new $className();
}
return $_instance;
}
function put($object) {
$self = Singletons::_instance();
$className = $object->getClassName();
$self->objects[$className] = $object;
}
function get($className) {
$self = Singletons::_instance();
if(!empty($self->objects[$className]))
return $self->objects[$className];
else return '';
}
}
Singletons::_instance();
?>

Answer 2

You're getting the error because you're trying to call your function statically when it isn't a static method (function).
You need to specify the function as static:
static function getClassName() {
return 'Singletons';
}
That goes for every method you'd like to call statically.

Answer 3

If you declare a function as abstract in an abstract super class, then attempt to define it as static in a child class, you will get a fatal error. You may want to think about the way your class hierarchy is structured, as your only option will be to remove the abstract function declaration from the super class.