| Uploader: | Viketij |
| Date Added: | 14.03.2017 |
| File Size: | 18.25 Mb |
| Operating Systems: | Windows NT/2000/XP/2003/2003/7/8/10 MacOS 10/X |
| Downloads: | 45360 |
| Price: | Free* [*Free Regsitration Required] |
MK-Design-Pattern/Head First Design blogger.com at master · ksatria/MK-Design-Pattern · GitHub
DOWNLOAD PDF. Table of Contents (the real thing) Intro Your brain on Design Patterns. here your brain is doing you a favor by making sure the learning doesn’t stick. Your brain’s thinking, “Better leave room for more important things, like which wild animals to Estimated Reading Time: 8 mins Kumpulan file matakuliah Design Pattern. Contribute to ksatria/MK-Design-Pattern development by creating an account on GitHub and co-author of Design Patterns “‘Head First Design Patterns’ manages to mix fun, belly-laughs, insight, technical depth and great practical advice in one entertaining and thought provoking read. Whether you are new to design patterns, or have been using them for years, you are sure to get something from visiting Objectville.”
Head first design patterns pdf free download
This content was uploaded by our users and we assume good faith they have the permission to share this book.
If you own the copyright to this book and it is wrongfully on our website, we offer a simple DMCA procedure to remove your content from our site. Start by pressing the button below! Home Add Document Sign In Register. Head First Design Patterns Home Head First Design Patterns.
That was until I le Author: Elisabeth Freeman Eric Freeman Bert Bates Kathy Sierra. DOWNLOAD PDF. That was until I learned the power of extension at runtime, rather than at compile time. Now look at me! this is a new chapter 79 the starbuzz story Welcome to Starbuzz Coffee Starbuzz Coffee has made a name for itself as the fastest growing coffee shop around. When they first went into business they designed their classes like this stract class, Beverage is an abbe verages subclassed by all ff ee shop.
The getDescription method returns the description. Beverage description The cost method is abstract; subclassses need to define their own implementation. DarkRoast HouseBlend cost cost Decaf cost Espresso cost Each subclass implements cost to return the cost of the beverage. Starbuzz charges a bit for each of these, so they really need to get them built into their order system.
What happens when the price of milk goes up? What do they do when they add a new caramel topping? This is stupid; why do we need all these classes? Subclasses will still override costbut they will also head first design patterns pdf free download the super version so that they can calculate the total cost of the basic beverage plus the costs of the added condiments.
e boolean These get and setndthiments. needs to compute Each cost methobedverage and then the cost of the ents by calling the add in the condim tation of cost.
This is definitely the way to go. Sharpen your pencil What requirements or other factors might change that will impact this design? Price changes for condiments will force us head first design patterns pdf free download alter existing code. New condiments will force us to add new methods and alter the cost method in the superclass.
We may have new beverages. For some of these beverages iced tea? What if a customer wants a double mocha? rn: Your tu 84 Chapter 3 aw in this is s e As w pter 1, idea!
Cha ery bad av the decorator pattern Master and Student Head first design patterns pdf free download Grasshopper, it has been some time since our last meeting. Have you been deep in meditation on inheritance? Student: Yes, Master. Master: Ah yes, you have made some progress. So, tell me my student, how then will you achieve reuse if not through inheritance?
Master: Please, go on Student: When I inherit behavior by subclassing, that behavior is set statically at compile time. In addition, all subclasses must inherit the same behavior. Master: Very good, Grasshopper, you are beginning to see the power of composition. Student: Yes, it is possible for me to add multiple new responsibilities to objects through this technique, including responsibilities that were not even thought of by the designer of the superclass.
Master: What have you learned about the effect of composition on maintaining your code? Student: Well, that is what I was getting at. By dynamically composing objects, I can add new functionality by writing new code rather than altering existing code. Master: Very good. Enough for today, Grasshopper. I would like for you to go and meditate further on this topic Remember, code should be closed to change like the lotus flower in the evening, yet open to extension like the lotus flower in the morning.
you are here 4 85 the open-closed principle The Open-Closed Principle Grasshopper is on to one of the most important design principles: Design Principle Classes should be open for extension, head first design patterns pdf free download, but closed for modification. Feel free to extend our classes with any new behavior you like, head first design patterns pdf free download. If your needs or requirements change and we know they willjust go ahead and make your own extensions.
It must head first design patterns pdf free download closed to modification. Our goal is to allow classes to be easily extended to incorporate new behavior without modifying existing code. What do we get if we accomplish this? Designs that are resilient to change and flexible enough to take on new functionality to meet changing requirements. That sounds very contradictory. How can a design be both?
It certainly sounds contradictory at first. After all, the less modifiable something is, the harder it is to extend, right? Think about the Observer Pattern in Chapter by adding new Observers, we can extend the Subject at any time, without adding code to the Subject. Q: Okay, I understand Observable, but how do I generally design something to be extensible, yet closed for modification?
Making OO design flexible and open to extension without the modification of existing code takes time and effort. Following the Open-Closed Principle usually introduces new levels of abstraction, which adds complexity to our code. You want to concentrate on those areas that are most likely to change in your designs and apply the principles there. Q: How do I know which areas of change are more important? A: That is partly a matter of experience in designing OO systems and also a matter of the knowing the domain you are working in.
Looking at other examples will help you learn to identify areas of change in your own designs. A: While it may seem like a contradiction, there are techniques for allowing code to be extended without direct modification. Many of the patterns give us time tested designs that protect your code from being modified by supplying a means of extension. How can I make every part of my design follow the Open-Closed Principle?
Remember us? Starbuzz Coffee? Do you think you could use some of those design principles to actually help us? cost DarkRoast 2 t DarkRoaasnd has t a h t r e b Remem from Beverage mputes inherits method that co a cost of the drink. the cost The customer wants Mocha, so we create a Mocha object and wrap it around the DarkRoast.
Its ject is a decorisatdecorating, The Mocha obth object it type mirrors Beeverage. we mean it is cost cost DarkRoast Mocha 3 oo, st method tn treat co a s a h a ch o e ca So, M olymorphism w and through p wrapped in Mocha as any Beveragetoo because Mocha is a a Beverage, head first design patterns pdf free download, Beverage.
subtype of The customer also wants Whip, so we create a Whip decorator and wrap Mocha with it. So, a DarkRoast wrapped in Mocha and Whip is still a Beverage and we can do anything with it we can do with a DarkRoast, including call its cost method.
We do head first design patterns pdf free download by calling cost on the outermost decorator, Whip, and Whip is going to delegate computing the cost to the objects it decorates.
Once it gets a cost, it will add on the cost of the Whip. ge a few pa Mocha, head first design patterns pdf free download.
cost t. ß Decorators have the same supertype as the objects they decorate. ß You can use one or more decorators to wrap an object. ß Given that the decorator has the same supertype as the object it decorates, we can pass around a decorated object in place of the original wrapped object, head first design patterns pdf free download.
ß Objects can be decorated at any time, so we can decorate objects dynamically at runtime with as many decorators as we like. Decorators provide a flexible alternative to subclassing for extending functionality.
Each component can be used on its own, or wrapped by a decorator. It extends Component. ent the Decorators implem abstract same interfacemorponent they class as the co corate. th en on mp state of the co Decorators can add new methods; however, new behavior is typically added by doing computation before or after an existing method in the component. r Beverage acts asneou class. coffe Milk Whip Soy Mocha Beverage beverage Beverage beverage Beverage beverage Beverage beverage cost cost cost cost getDescription getDescription getDescription getDescription And here are our condiment decorators; notice they need to implement not only cost but also getDescription.
Sue: What do you mean? Mary: Look at the class diagram, head first design patterns pdf free download. The CondimentDecorator is extending the Beverage class.
What is the Decorator Pattern? (Software Design Patterns)
, time: 19:41Head first design patterns pdf free download
26/11/ · With Head First Design Patterns, 2nd Edition you’ll learn design principles and patterns in a way that won’t put you to sleep, so you can get out there to solve software design problems and speak the language of patterns with others on your team. blogger.coms: 7 Kumpulan file matakuliah Design Pattern. Contribute to ksatria/MK-Design-Pattern development by creating an account on GitHub Books. Contribute to ajitpal/BookBank development by creating an account on GitHub
No comments:
Post a Comment