I'm recently getting a bit confused with interfaces and abstract classes and I feel I dont fully grasp it like I thought I did. I think I'm using them incorrectly. I'll describe what I'm doing at the moment, the problem I have faced, and then hopefully it be clear what I'm doing wrong if anything.
I wanted to write some classes that do some parsing of xml. I have different user types that have different parsing requirements.
My logic went as follows.
All parsers share a "parse" function in common and must have at least this function so I made an Interface with this function defined named IParse;
I start out with 2 user types, user type A and user type B. User type A & B share some basic functions but user type B has slightly more functions than A so I put the functions to parse what they share in an abstract class that both will extend called "ParseBase".
So now I have
// Interface
public interface IParser
{
function parse(xml:XML):void;
}
// Base Class
public class ParseBase()
{
public function getbasicdata():void{}
public function getmorebasicdata():void{}
}
//User type A
public class userTypeA extends ParseBase implement IParse
{
public function parse(xml:XML):void
{
getbasicdata()
getmorebasicdata()
}
}
//user type B
public class userTypeB extends ParseBase implement IParse
{
public function parse(xml:XML):void
{
getbasicdata()
getmorebasicdata()
}
public function extraFunctionForB():void
{
}
public function anotherExtraFunctionForB():void
{
}
}
The problem I have come up against now which leads me believe that I'm doing something wrong is as follows.
Lets say I want to add another function UserTypeB. I go and write a new public function in that class. Then In my implementation I use a switch to check what Usertype to create.
Var userParser:IParser
if(a)
{
userParser= new userTypeA();
}else if(b)
{
userParser= new userTypeB();
}
If i then try to access that new function I can't see it in my code hinting. The only function names I see are the functions defined in the interface.
What am I doing wrong?