Simple Question

[Fandu_Nagesh]

Hi Gurus
I want to know the details of White box reuse and Black box reuse ?....Whts they makes difference in design?

Regards
Nagesh

[galathaea]

Black box reuse ise the distribution of compiled components for implementation into a larger development construction, whereas white box reuse indicate the actual distribution of source code to include into a software project. This article (http://e-serv.ebizq.net/dvt/fay_1.html) explains in more detail the relative benefits.

[Fandu_Nagesh]

Thank you Galathea...
Actualy I was reading the MSDN, for OOP concept. While reading I Interface based programming , I came through these words...at that time I could not get the clear idea about the meaning of these two.....
The linked article is more informative to understand the concept...
Thank you
Regards
Nagesh

[TheCPUWizard]

Slightly longer answer.

"Black Box".. You have knowledge of WHAT is does, but not HOW it does it. A pure interface class is a decent example.

"White Box".. You have FULL knowledge about everything. Galathaea example of source code is a good one.

These terms are used in both reuse and testing methodologies.

There are also many "Gray Box" issues...You have partial knowledge of "how". This can be as simple as a DLL Vendor stating that "Object X uses a CMap to hold its data". You now have some knowledge of how and can tune your usage to optimize on this. There is a risk as the vendor may later make an internal change (i.e. no public methods change).

In the testing area, this idealy resolves to:

"Black Box Testing"..Test every method under all possible conditions.

"White Box Testing"..Make sure every code path is executed, all variables are tested for over/under flow, etc.

Hope this helps..

[Fandu_Nagesh]

Hi CPUWizard
Thank you, Actully the small informative para. helped me to clear all those confusions.....you kept the idea in simple words...its more helpful. Even Galthea's example is good...
Thanx you Guru...
Reagrds
Nagesh