is PetShop 2.0 Anti pattern?

Hi,

I was seeing code of PetShop 2.0 and find is quite .. differnet design
and architecture ..

too much of clutter in classes .. order class using and Iorder and
Iorder using an orderInfo and same for product, is this good design
...is it MS design principles?

I just learning the nacks of application designing and architecture and
i dont know how should be my thinking process ..should i think in
Classes/object or what way.. ?

by the way i have joined these formums just few days back ..and i say
its simply superb you all experts out there trying to help people like
us.. SALUTES.


Comments Please

 

a large group of developers (especially the test first design) believe in
interface design, and that only interfaces should be used. Interfaces define
contracts, and classes implement contracts in this design model.

-- bruce (sqlwork.com)

 

I have read this line many times " Interface define Contracts" what
does this mean technically, can please explain me with an example, also
i want to know whether having interfaces for all your classes is good
idea?

Thanks in advance

 

Interfaces define contracts of service.
Interfaces do not define implementation details.

The specification of the contract of a component includes the
input/output behavior, invariance and dependencies to other components.

Architecturally, interfaces encapsulate nodes and provide clear access points.
A component or a service is visible exclusively through its interface.

If your class doesn't include a component or a service,
i.e., if its properties and/or methods can be called directly, it doesn't need an interface.

See :
http://discuss.develop.com/archives/wa.exe?A2=ind0203d&L=dotnet&D=1&T=0&F=&S=&P=93506
and :
http://scholar.lib.vt.edu/theses/av...d2.pdf#search=""interfaces define contracts""