Using $this inside a static function fails

This is the correct way

public static function userNameAvailibility()
{
     $result = self::getsomthin();
}

Use self:: instead of $this-> for static methods.

See: PHP Static Methods Tutorial for more info :)

You can't use $this inside a static function, because static functions are independent of any instantiated object. Try making the function not static.

Edit: By definition, static methods can be called without any instantiated object, and thus there is no meaningful use of $this inside a static method.

Only static functions can be called within the static function using self:: if your class contains non static function which you want to use then you can declare the instance of the same class and use it.

<?php
class some_class{
function nonStatic() {
    //.....  Some code ....   
    }
 Static function isStatic(){
    $someClassObject = new some_class;
    $someClassObject->nonStatic();
    } 
}
?>

The accessor this refers to the current instance of the class. As static methods does not run off the instance, using this is barred. So one need to call the method directly here. The static method can not access anything in the scope of the instance, but access everything in the class scope outside instance scope.

It's a pity PHP doesn't show a descriptive enough error. You can not use $this-> inside a static function, but rather use self:: if you have to call a function inside the same class