 |
3. - Moduleco, an object oriented modular
Framework,
3.1. What is a framework ?
(c) advantages and constraints of this approach
|
   |
Advantages
Very few code lines are necessary to develop new models
and services …
Implies specialisation and modularity Difficulties
:
-
the framework must predict as perfectly as possible future
evolutions
-
the framework must be able to evolve by way of adaptations…
Constraints
To use the names and methods as expected by the framework.
As a consequence, further developments depend on :
-
the structure of the framework
-
the knowledge of the possibility to redefine methods and
variables
-
Knowledge of the « entry point »
As seen earlier, a framework represents the common and shared part
of many applications. It delimits all the possible applications that can
be made by extension. But thanks to the inheritance feature of OO and the
redefinition of methods, it is (almost) always possible to specialise and
add very new behaviours. If these new behaviours are considered as general
enough, it is possible to change the framework, while integrating the new classes,
methods. A framework is the stable part of common applications, but
is never frozen.
The powerful advantages of frameworks are compensated by some constraints.
In order to use them efficiently you would not simply have to know their
functions (as for classical libraries) you also need to know their structure
(inheritance hierarchy) and most of their "entry points", i.e. the methods
the frameworks allows (or expect) to be redefined.
A good framework is somewhere between a "black box" component, where
you just have to know its interface (functions), and a "white box"
component, where you need to know everything inside the component to be
able to use it. A framework is in some way a kind of "grey box"...
In the following, we will present the main classes and entry points
of Moduleco.
Denis.Phan@enst-bretagne.fr,
Antoine
Beugnard@enst-bretagne.fr