Decorator Design Pattern 

Learn in One Videos for Every Programming Language Subscribe to Bookmark them: bit.ly/2FWQZTx C++ : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Rub-JsjMhWY.html Python : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-N4mEzFDjqtA.html Java : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-n-xAqcBCws4.html PHP : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-7TF00hJI78Y.html MySQL : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-yPu6qV5byu4.html JavaScript : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-fju9ii8YsGs.html C# : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-lisiwUZJXqQ.html HTML5 : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-kDyJN7qQETA.html CSS3 : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CUxH_rWSI1k.html JQuery : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-BWXggB-T1jQ.html TypeScript : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE--PR_XqW9JJU.html ECMAScript : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Jakoi0G8lBg.html Swift : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-dKaojOZ-az8.html R : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-s3FozVfd7q4.html Haskell : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-02_H3LjqMr8.html Handlebars : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4HuAnM6b2d8.html Bootstrap : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-gqOEoUR5RHg.html Rust : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-U1EFgCNLDB8.html Matlab : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-NSSTkkKRabI.html Arduino : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-QO_Jlz1qpDw.html Crystal : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DxFP-Wjqtsc.html Emacs : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Iagbv974GlQ.html Clojure : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ciGyHkDuPAE.html Shell : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-hwrnmQumtPw.html Perl : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-WEghIXs8F6c.html Perl6 : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-l0zPwhgWTgM.html Elixir : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-pBNOavRoNL0.html D : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-rwZFTnf9bDU.html Fortran : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-__2UgFNYgf8.html LaTeX : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-VhmkLrOjLsw.html F# : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-c7eNDJN758U.html Kotlin : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-H_oGi8uuDpA.html Erlang : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-IEhwc2q1zG4.html Groovy : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-B98jc8hdu9g.html Scala : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-DzFt0YkZo8M.html Lua : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-iMacxZQMPXs.html Ruby : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-Dji9ALCgfpM.html Go : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-CF9S4QZuV30.html Objective C : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-5esQqZIJ83g.html Prolog : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-SykxWpFwMGs.html LISP : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-ymSq4wHrqyU.html Express : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-xDCKcNBFsuI.html Jade : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-l5AXcXAP4r8.html Sass : ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-wz3kElLbEHE.html

Move the "adding dough" to plain pizza class then the video is perfect!

10 years later and this video is still one of the easiest to follow and best videos on a design pattern I've seen so far! Thank you!

I'm happy they have been able to help you :) I decided a long time ago that I wanted to make long videos, but I also wanted them to be interesting and keep the viewers attention. I'm starting to really like the final results as of late. It has been very fulfilling to work at improving my teaching style. Thanks for giving the videos a look!

You're very welcome :) I'm doing my best to cover the more complicated topics in programming. I'm glad people are finding them useful

Thank you :) I'm working from 6 different books to make this tutorial. I'll cover everything in the GOF book, but probably in completely different ways. I'm glad you are enjoying the tutorial

Thank you for taking the time to tell me I was able to help :) That is very much appreciated!

It is very nice to be able to clear up a subject when others haven't helped! Thank you :)

You're very welcome :) Think of those classes that extend ToppingDecorator as if they are layering on functionality to the Pizza composite field in the ToppingDecorator object. So, first you create the Pizza object and then add additional functionality to getDescription and getCost using the toppings. Here is another tutorial on decorator that may help further newthinktank. com/2013/02/code-refactoring-16/

Thank you for watching :) I'm glad to help

I have all of the diagrams on my site. There is a link in the description for the video. I hope it helps

You're very welcome :) Thank you for checking them out

I'm just happy that you find it useful :) Thanks for the kind words. It is just a fun hobby of mine and I expect nothing in return

Thank you :) I like covering niche topics that everyone else avoids

Thank you :) I do my best to cover complicated topics in easy to understand ways. I'm glad you liked it

I love this, thank you so much! It really helps to hear this concepts from someone rather that read boring books a thousand times for each pattern. It's really cool that you do this without expecting money or any type of retribution what so ever.

You're very welcome :) Yes you could do what you described. It is really my fault because I didn't make an example that required the added flexibility this pattern provides. I tried to come up with a simple example of the pattern and in doing so I didn't get the best example. Sorry about that

Bro, trust me, never find such great tutor where I can understand the design pattern so easily. You are the champ dude.

I read this pattern in Gang of Four today, was trying to figure out what the main method would end up looking like, very glad I found this video. None of my classes for my B.S. CompSci covered this stuff and I'm finding it very important for my job now.

I probably could have come up with a more specific optimized way to present this pattern. The ToppingDecorator could have been more simplified and then the ingredients could have done most anything. In videos I have to find an example that both demonstrates the pattern while keeping everything as simple as possible. Sometimes I get a great example and other times not so much. Sorry about that

Thank you very much :) I love covering niche topics that others ignore

You're very welcome :) Im glad you enjoyed it

I'm confused by your question. ToppingDecorator provides those methods to the classes that extend it

Man I'm hungry

That was a brilliant example demonstrating the decorator pattern . Thanks a million!

You're very welcome :) I'm happy they are helping

Thanks, it's a great video explaining the concept very well. One thing that bothers me about commonly used patterns in Java is that they are often un-intuitive and do not reflect the real world as well as they could. I think the Decorator pattern is one of these. For example at 12:00 you have this line: ``` Pizza basicPizza = new TomatoSauce(new Mozzarella(new PlainPizza())); ``` I would intuitively interpret as making Mozzarella from PlainPizza and then making TomatoSauce from Mozzarella. The example below achieves the same results without decomposition and with a lot less boiler plate code, just by changing the mental model to something more intuitive and representative of real life. Are there any advantages to using the Decorator Pattern in situations like this? ``` List toppings = ArrayList(); toppings.add(new Topping("TomatoSauce", 0.35)); toppings.add(new Topping("Mozzarella", 0.5)); ToppedPizza ready = new ToppedPizza(new PlainPizza(), toppings); ``` I'm sure there are cases where Decorators are needed but I often see programmers using certain patterns to fit the solution into the their mental model when they should be reframing their mental model to match real life. What are your thoughts / experiences regarding this?

I am a Senior Developer, I watched these videos from Derek 6 years ago, and yes I am watching them again :) #lifeOfDeveloper

Your videos are so great! I always recommend them to my friends taking the Software Design Pattern class at my university. Well done!

Thank you :) I'm glad you enjoy them

Thanks Derek for explaining decorator design pattern in such simple way... Hats off... cheers!!!

You have saved my ass. Exam in one week and I was not getting any of this until I discovered your videos. Hero!!!

Thank you very much :) It is very nice of you to say that!

Thank you :) I did my best and I'm glad you liked it

Yes I slipped up a bit. Thanks for pointing that out

Thank you so much for the excellent videos Derek, This is helping me a great deal in prepping for my CS exam! You are my hero!

When I start thinking about using a design pattern I normally first ask if I can accomplish making the code more readable in some other way. If I can't think of another way I use the pattern. You'll find with experience that more often then not you'll use patterns rarely. The positives in knowing them are that you'll start to find other unique ways of solving problems while writing easier to understand code.

Excellent. Thank you so much!!!!! I have read the Gang of Four book, but it is so long that the trees get lost in the forest. Your Decorator is so clear and logical. Bravo!

That's funny :) Thank you for the compliment. I'm glad you are enjoying them.

Thank you :) I'm very happy that I'm able to help.

First of all thank you very much. This is the best design pattern tutorials i have ever seen. We demand some more stuff from you in future :).

I always first see the running time of ur tutorials before playing. Then I feel like "ohh... so after 13 minutes the "future-me" would have learnt decorator pattern! Cool!!" Its better than counting the pages on a book n thinking "well... need to read 30 more pages to learn decorator pattern.. ahh forget it. will do later" I recently switched organization for almost double the salary (+ better work). And I owe u a big thanks since your videos were a very big help to me.

8 Years latter and still useful, thanks for the high quality video!

Thank you :) Im very happy that you enjoyed it

Hey Derek, i'm just going to reaffirm what others have been saying on your videos all along: thank you so much for this incredible resource for learning about design patterns. Your videos are of such incredible help while studying, both because of your excellent explanations, as well as the nature of the medium (we can replay a segment we don't understand however many times we want) and the commented code that you provide. I am a big believer of a future for internet with micro-transactions, so i just went and donated you 5 bucks. It is not much, i am a student after all, but the content you provide warrants a gesture from me :)

Thank you :) it was fun to cover this topic

are you sure you wanna have "Adding dough" in Mozarella class ? (10:00)

Hey man, i just gotta tell you that I love your videos and I love you. 3rd year of uni, and you still manage to help me through all the questions I have. Last semester you helped me out with Data Structures now you're helping me out with design patterns. Thank you once again, please keep this up!

Amazing! I'm from Ukraine, but your tutorial in English is easier than any of I could find in native language! Thanks!

Fantastic tutorial, very well presented and easy to understand. Wish more tutorials were as high quality as this one! :)

you're the master; never has anyone or any article or tutorial hit home design patterns to the point in such short and concise manner.

You can always override the PlainPizza class, add a topping of medium, large, Xtra large, etc. You could have all toppings have the same price and then just override the description. The rule extend what differs between toppings will steer you in the right direction

Sure I will cover the top 23 patterns described by the GOF

This is the best example to get the idea of decorator design pattern. Thanks Derek. :)

Thank you :) God bless you as well

You are a most excellent teacher. I usually have problems learning new (especially programming) concepts, but you made it very easy for me to understand. Your explanation is crystal clear. =)

Why? Why do you have a video about anything I look for? I love you bro.

Very Helpful tutorial, my first project in my Object Oriented Programming course just so happens to be creating a pizza ordering system where toppings are added using a decorator design pattern so this video was exactly what I needed! Thanks so much!

Headfirst design patterns explains things similarly but using drinks instead of pizza. You did a much better job of explaining it than the book did though.

man thanks, a year trying to understand this pattern xD it was so easy

Derek, your tutorials are the best! Highly respected!

Derek, You're the best man! The range of topics you have on your channel makes me wonder if there were a team of 4-5 different experts, but its just you, unbelievable. I would love to donate on your site once i have my paycheck. For this video, like others i do have some issues with code or the way it could've been done, but i understand the focus here is understanding the pattern and not the code that is written, Thumbs UP!!, You're awesome!

For those who don't know about SOLID principles, I recommend reading up on it. "Clean Architecture" by Robert Martin is a really good resource for this but you can just Wiki it. This design pattern is very powerful in that it directly tries to comply with the S(single responsibility) and O(open/close) of SOLID.

Thank you :) I pay no attention to video count, views, or anything else. You guys seem to inform me on that stuff

Thanks a lot for providing the code. Sometimes I don't quite get things through verbal explanations, but seeing you implement it and then thoroughly going through the code afterward really helped it click. Also, I think at the end of your tutorials that involve coding, you should do one final overview of what just happened when you run the program. In this video for example, I think you could've taken us through how the objects were being wrapped.

Awesome. Much better explanation than HeadFirstDesignPatterns. Hats off.

The UML association in the diagram is *composition*, not aggregation. Aggregation uses an empty diamond.

I keep rewatching these series of design patterns in java. So far it helped me make my apps less violent and less complicated. Also, I love pizza! My thanks for your effort Derek. Kind Regards...

You are very kind :) You're very welcome

I took a short cut. You are correct that I should have defined a Dough class like I did with TomatoSauce. I was just being a bit lazy. Sorry about that

Thanks Derek just having this topic on my OOP Class.. and it helps a lot. Cheers mate.

It's nearly 1 AM and I'm hungry because of you, thanks

Great! You're very welcome :)

Every video from this course helps me to obtain clear understanding of dedicated pattern. Nice work! One remark about Decorator Pattern. You've forgot to implement decorators for meat stuff and olives to obtain perfect pizza :)

Great video on the Decorator pattern Derek! Loved it!

Thank you, but you don't have to do that. I'm not one of the guys that asks people to like and favorite everything. The fact that you find them useful is enough for me :)

learning for my software engineering course for university right now and have to learn all of these by heart and these videos are very helpfull thank you

You're very welcome :)

You should be hired as a tutor at my college. You just saved me 5 hours to say the least, while providing me with information in the most appropriate way. And this is not the first time...

Sorry, but I'm not sure what you are trying to do. Send me a message on youtube, or and email derekbanas@verizon.net

Absolutely the best I have ever seen in video programming tutorials! You are doing a fantastic job!

He sounds a little bit like Andy from The Office (Ed Helms)

Incredibly easy to learn !!!! THANK YOU !

Thanks for the video .. They are really helpful .. Rather than reading the GangOfFour book this is much precise and better to be done over a weekend

Hey Derek, correct me if I'm wrong. So the basic difference between Abstract Factory design pattern and Decorator design pattern is: 1. When you can create an object many different "definite" ways, use "Abstract factory design pattern". Also disadvantage is, you have to create a factory for every possible combination. More of a static factory. 2.When you can create an object many different "indefinite" ways, use "Decorator design pattern". Here you can dynamically combine any possible combinations. More of a dynamic factory.

Very nice. All your tutorials are great, thanks!

Awsome tutorials, I'm preparing for my exam with your videos!! The examples are excellent

Thank you :) i did my best with them. I found an answer for your question that I agree with here: stackoverflow. com/questions/2166632/can-you-remove-a-decorator

Excellent, concise yet easy to understand. Thanks you!

Good Stuff! All the design patterns are well explained. Thanks! :)

This is superb place for learning design pattern. Thanks Derek..

The pizza example used in this video is very effective in understanding Decorator Pattern. The method of inheritance as described in the video is static and will not allow for changes in the code. Hence, it is important to use design patterns because good code is easily manageable and changeable. Using design patterns will allow the client to easily add new toppings to pizza, change the cost of each topping without having to make major changes in the code. An advantage of using decorator pattern particularly is that it uses the code already written and just extends it for additional functionality. The detailed coding example is very helpful in understanding how the decorator pattern functions. Though thespeaker makes an error while coding where he refers to methods as classes which might confuse new programmers.

Thank you so much! Clear explanation, I love you!

no wories, i just wantes to say something really :-) your lectures are very good

This video is 1000 times better than how my teacher tried to explain it to us, why thanks ;)

My Best channel to learn OOP and DP Great job guys

That's funny :) I'm glad you liked it

"Concrete Pizza" Sounds Delicious ;) 5:01

Great video! When I think about creating a pizza class with many different kinds of toppings, I might choose the builder pattern instead, so that my code for adding toppings can be linearly written instead of in the form of nested constructors. Are there any advantages of the decorator pattern over the builder pattern here?

Great Videos! very well explained, great examples, just great, thank you very much!