Need create and call method from many class types

[WojTec]

Hello, guys,

So, lets say what I have.

I have two classes:
- TClass1(TBaseClass)
- TClass2(BaseClass)

TClass1 and TClass2 extands TBaseClass, both are for different input data types. TClass1/TClass2 has LoadFromStream and SaveToStream.

Now, how to create and call methods with names that are common for any class TSomeOtherClass(TClass1/TClass2), like stream procedures?

Currently I have:

if class = someclass then someclass.loadfromstream
else if class = otherclass then otherclass.loadfromstream
else if class = yetanotherclass then yetanotherclass.loadfromstream

but in future I'll have too many classes to add if statement in few places in few units in program.

Could you help with this?