| General Purpose
Classes Classes that place all
potentially required functionality into one
ancestor class belongs to this category. That
means methods are defined for any possible
functionality for that object. When the developer
use this class, he turns on and off the
functionality in one of the following ways:
 |
Call the method
with a lot of arguments with TRUE/FALSE
values. ( In the ancestor class, the code
uses IF...ELSEIF
statement to check the argument value and
acts accordingly ) |
|
Call separate
functions to turn on/off the
functionality and then calls the actual
method. ( In the ancestor class, boolean
instance variables are defined and in the
method’s code IF...ELSEIF
statement is used to check whether the
instance variable is turned on/off. ) |
A
typical example of a general purpose class is a
DataWindow with all the functionality as shown in
the following picture:
Fat
Ancestor DW UO with all the required functions.
There
are a few disadvantages with the general purpose
classes:
|
Fat ancestor
classes |
|
Potentially
unnecessary functionality in some
situations. For example, a method to add
a new record is not required when the
DataWindow is used for reporting purpose. |
|
