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Head First Design Pattern Question

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Head First Design Pattern Question

(http://benreichelt.net/blog/2005/5/23/Head-First-Design-Pattern-Question/)

Published May 23 2005, 09:42 PM by breichelt

Comments

Thomas Eyde said:

Isn't Decorator some kind of a last resort? Something you use when you need to change what's already there, but you can't do the way you want?

In this context, Decorator makes sense in the coffe shop, because they are expanding an existing architecture. If the pizza shop is starting from scratch, then you don't have that limitation.

I am guessing on the pizza shop, as I haven't bought the book yet, only read the sample chapter.

# May 24, 2005 3:44 AM

breichelt said:

Interesting, I have to go back and look at that chapter again, its been awhile since I read that one, I'll report back :-)

# May 24, 2005 5:40 AM

first: i love the book, great way to introduce patterns to a developer...

second: i think it was merely an example of the factory pattern. straight up. just as in actual development, there are also a million ways to describe the same thing.

# May 24, 2005 6:41 AM

darrell said:

I think Thomas is right about the "last-resort" thing. Decorator ends up having tons of wrappers, and in their example you'd have to do a lot of work to re-order the coffee decorators to say "double-mocha" whereas if you had developed it differently, double-mocha is easy.

# May 24, 2005 7:45 AM

Jason said:

You could use a decorator pattern to encapsulate the pizza toppings if you wanted to.

The point of the factory is that the assembling of the class is encapsulated by the factory, so you could swap one factory for another.

# June 20, 2005 11:43 AM