Question

Let say i have this class

class Test
{

   method_a(){ return $this;}

   method_b(){ return $this;}

   method_c(){ return $this;}
}

$obj = new Test();
$obj->method_a()->method_b();
$obj->method_a()->method_c();
$obj->method_b()->method_c(); //i want to disallow this

How can i disallow method_b() chaining with method_c()

Edited:

Calling $obj->method_b() and follow by $obj->method_c() also disallow because i only want method_b chaining with method_a and method_c with other method

Answer 1

You could use a State Pattern and introduce State objects for each possible state in Test. When someone calls Method B, you change the state of Test internally to the StateB class and when someone calls Method C then you can raise an Exception.

See http://sourcemaking.com/design_patterns/state