The community is missing someone like you. 2023 and we still enjoy such 37 min in a row.

Dude I really like how you repeat every one of your definitons at least twice... The first time to hear it and the second time to rethink it! You are a great teacher!

"Instead of calling the THING you want to call you call the THING which call the THING you want !!" Nice definition, liked it!

00:01 The proxy pattern provides a surrogate or placeholder for another object to control access to it. 01:56 Proxy pattern is used to control access to resources and solve access-related problems. 06:01 Proxy pattern adds additional behavior to control access to the underlying object. 07:58 Using a virtual proxy allows for additional behavior before making calls to an object. 12:12 Using methods is a flexible approach that allows for future changes. 14:13 Premature optimization can lead to inefficient code 17:59 Proxy pattern allows deferring the instantiation of the underlying book parser 19:42 Proxy pattern is used to create expensive objects on demand rather than immediately. 23:23 Proxy pattern is used to control access to an expensive operation. 25:11 The proxy pattern controls access to the real subject and follows the same interface. 28:44 The proxy pattern involves a proxy class that acts as a placeholder for another class, known as the real subject. 30:17 Create an instance variable that defaults to null for Lazy Book Parser Proxy. 33:58 The proxy pattern delays the instantiation of a concrete book parser until it is needed. 35:44 The proxy pattern allows instantiation of the book parser only when required, improving performance.

You are an effective and succinct communicator. You make learning infectious. Are you a professor or desiring to be? As online learning continues to become an educational alternative, and given the increasing university tuitions, online instructors like you are becoming a threat to the educational status quo. You have a gift and I believe it will take you very far in your career. EXCELSIOR!

My mood rises when I see new episode. Thanks a lot MAN!

I'm reading the Head first design patterns book, I used to think that I already had a good understanding of OOP, but that book changed everything, I realized I just knew the name of the tools and maybe how they were written in java, but I had no idea how to use them, after learning about design patterns marked a new start for me. I came here to have some help with the Proxy pattern and you were awesome, thank you, now I'll go ahead and start reading the chapter about the proxy pattern in the book, keep it up man, you are a great teacher.

Great video, but can you move ur camera slightly to the right next time so i can see the cat better? :P

The best Design Pattern playlist on KZfaq! Your explanation skills are very powerful...listening to you is funny and not boring! Thanks to you I'm gonna pass my exam on Design Pattern!

Bruh!!, I watched this before my final and you made it super easy to understand. Hours of reading on this pattern were pointless. Crystal clear explanation. Keep it up and two thumbs up!

The one reason I keep coming here is that he keeps repeating what he is teaching. That really helps to understand the topic better. Great contents!

Hi, I am a student from Taiwan, I really like your explanation, really help me a lot! Thanks!

open, smash 'like' button, watch - my algorithm for your videos. I call this pattern "gratitude". Thanks a lot for your great job!

I was completely lost, and i had to understand and learn design patterns. i found this channel, and now i get it all. thanks for your time and effort Chris.

We need more people like you! Everything I search on KZfaq for Object-oriented programming is either trival or just not helpful. Thanks to you I understood the patterns I needed to understand for my exam. Thanks!

I really like the effort you give while explaining the concept. you are very good teacher. Hard to find teacher like you

I completely lost track after that cute student walked into the class. :D

Great Job!! I have never seen any video that explains design patterns so clearly. Thank You for making my life easier to understand Design Patterns.

I am really upset i did not find your tutorials all these years on KZfaq when ever i searched for "design patterns with Java". But better late than never. Thanks dude.

I had astigmatism and I started wearing new glasses. I was happy to see everything clear. Until I watched this video: D.Even so thanks for your informative video :)

I just don't understand how do you manage to make it so simple... Thanks alot for this wonderful explanation... 😀

Man, your examples, just make it so easy, it was a nightmares before i know this playlist, thank you

Great video. Content and explanation were really useful, thanks! I know you mentioned the autofocus and are aware of it but just a suggestion: Perhaps avoid using autofocus all together? Use a deeper depth of field and set your focal point to 2/3rds of the distance from the whiteboard. After this is set, leave the focus for the entire video. There's no need for the camera to be constantly re-adjusting focus as you move your arm back and forth because that data is irrelevant to what the viewers need to see.

Bringing up the "Premature optimization" is brilliant 💡. Thanks!

This is by far the best explanation of the proxy pattern I've watched on youtube! Thank you!

114 likes, 0 dislike ... I'm really NOT surprise .. your explanations are perfect

Instead of book I prefer to watch this playlist again xD

I love your explanation that patterns have different intent even if implementation strategies match sometimes.

Hey Christopher, thanks for sharing these knowledge so generously, hope everything's well with you.

Your explanation of concepts and examples are easy to understand! I even treat it as a kind of relaxation! Though I fell asleep for times in this episode (maybe just because I watched it after dinner...), I found I was still keeping up with the pace of the video :) Thank you so much!

Learnt first 10 design patterns and done for now. Will come back later, maybe during the 2nd half of 2020.

maan, I've been watching these videos and writing notes all day long. Thanks.

Excellent explanation! Thank you so much!

As usual amazing explanation Chris. Keep up the good work. Thanks a lot.

I started to see your videos yesterday night 10PM. Now it’s morning. Amazing videos….. Keep it up. One suggestion will be, please take best of best book in each computer subject and do like this. I bet you, you will become the KZfaq star. People from India simply love Liza koshy. So they will love you too…...

It would have been pretty cool if you had talked a little bit about how virtual proxies can also override a client's method or property. This, in my opinion, makes virtual proxies super powerful (assuming, of course, that the language allows for it and that the client class has been defined appropriately) Thanks a lot for the great video!

Man I love your videos. You make things that were unclear to me looks like really super easy.

Group of Devs said design patterns are difficult till Christopher enters the room.

These videos are amazing. You should create a design pattern playlist for easier consumption

Hi Christopher, I must firstly say that you’re a great teacher. I’ve been feasting on your presentations on Design Patterns and enjoying every bit of it. I’ve looked at this particular tutorial 3 times but I couldn’t seem to grasp the concept properly then I found why: I think your example don’t quite fit the pattern. Here’s why: The base interface on the right, ie the Implementor needs to itself be a specialised form of the Abstraction hence the name Implementor. With this understanding the definition makes total sense “Decouple an abstraction from its implementation so that the two can vary independently”. In your example IResource would need to be a specialised version of View to fit the Bridge Pattern which makes no sense. My comment is not to take away from your work by the way, your work is awesome stuff. Let me know what you think. This is a really powerful pattern.

Hey Christopher, Thank you very much for making these videos. I know they’re a lot of work. You teach the way I think. If that makes sense. Brilliant job!!!

Christopher Okhravi, create more content. You explain very well and in depth !!

Chris, you're an awesome pedagogue !!! Thanks a lot !

I think what you mentioned around 11-12 minute is "encapsulation" , where you can access the field through method instead, by using setter and getter method. cmiiw

Man i'm here now, and with your help i'm trying to learn the design patterns. Just for info you talk so fast also with 0.75 play speed😂. Great work dude!

Someone would say ANOTHER ONE! Great Job Dude!

great video. Guess, who uses the proxy pattern heavily as you've said for the lazy initialization? of course, hibernate. When you declare explicitly that I'd like to have an object lazily initialized, hibernate obliges it by using proxy around it. So that ORM class is instantiated only when we 'really' want to do something on it, until then it is just hanging around there as a simple proxy class . Again, great video!

Hello Christopher, I like your videos and the way you explain it...I have been following your videos for my better understanding abt DP....Can I request you about including real business scenario where we can implement these DP's...Please have a 10 min of slot in your video abt telling us real scenarios where we can implement this DP....

Very well explained. we love your lectures and your cat.

Very, very good video. Thanks, I hate how many video's are decent, but you cannot understand the person who is speaking. You anunciate very well and you do a great job of driving home a point.

Thanks Christopher for you detailed view on patterns.. I really find them very informative and like the simple way you have explained these topics. Keep the good work .. Way to go.. :)

27:33 cute cat!!!

I love your work. Thanks a lot. Please continue this series

Regarding the performance vs readability, I tend to lean towards performance - within reason. I've encountered many times where someone wanted to significantly reduce performance for the sake of improving readability slightly. I hear the same thing a lot, "don't worry about performance until it's an issue," but that's one of the big problems in our society - people don't want to do anything that takes effort until there's an actual bonafide problem (and sometimes not even then). If you intentionally hinder the performance a small amount for the sake of readability and then do that 1000 times across a system, it can take a lot of unnecessary effort to identify which pieces need to be updated, which are the worst offenders, how to fix them, etc. It might be obvious which option is more performant vs readable when it is being written/reviewed, but 6 months, a year, 3 years later, that knowledge is probably lost.

8:04 NOOOOOOOOOOOOOOOOOOOOOOOOOO ! I did not have time to take notes !!!! 😱😱😱😱😱😱😱 No seriously this is good and I have OneNote opened to keep the important bits. About autofocus I'd say in the context in which you shoot, you'd probably better find a manual setting that works. Autofocus is dynamic and can misinterpret the subject at times. With a long enough depth of field you could not need to change anything at all and be sure the image is neat for the desired scene setup. The smaller the aperture the longer the depth of field but also the less light = greater likelihood to need external light.

Thanks for such a brilliant series on the design patterns. Would like to know more about improving application performance from developer's perspective, but in "Christopher Okhravian" style.

Your content is really good tho. I can't wait to see what more interesting things you're going to bring to the channel!

Thanks for the easy-to-understand explanation & cat though 😀

quite interesting and explain in an abstract way. which make it more interesting. appreciated your efforts keep it up buddy..

You are a great teacher .....Love from India .

you are AWSOME keep up the good work, it helped me so much. thank you

Awesome as always, you are a very good teacher! Just a question: what about the GoF patterns which the book "Head first" doesn't explain? Are you going to make some videos about them? I hope so, it would be great :D

Question: is it still appropriate to use proxy pattern when you own the original object implementation? It makes sense to proxy another library object to enhance or change it’s behavior. But does it make sense to proxy your own object that you could just modify instead of proxying? I know of the open-close principals. So proxying already existing object that I own the implementation of would obey the open-close principle but also would possibly create layers upon layers upon layers. Also, I’d like to hear more on dangers and gotchas of each pattern.

A real case where I have seen a proxy being used was when our architect made the system into three layers, we had a lot of sensitive code that we didn't want to edit, so some of the classes of the core of the application became proxies to to the data access layer, which otherwise would have been nothing but duplicate code in a separate assembly

Great video as always! small criticism: I think a better example would be to introduce a "setBookString" method instead of working with constructors. Since the constructor is not part of the IBookParser interface, we can not really rely on it when Proxying the BookParser class.

you really helped me during my exams. thanks bro

Cool! This is the first video I saw from you, but I immediately subscribed.

Best examples of Proxy pattern are Mockery(mocked objects or services) as used in unit testing.

Great Video!!

great! Thank you!

Well explained. Very clear. Now I understand the cat pattern... I mean proxy pattern.

Thanks for explaining proxy with such ease to understand. I have one thing in my mind that is LazyBookParserProxy is not thread safe while creating instance of RealBookParser, we may end up having multiple RealParser

Hey Christopher , Thank you very much for this great video series . According to the code that you have mentioned at last it seems same to singleton pattern.(one time creation object) Can you please brief me how this proxy pattern is difference from singleton pattern ??

I never thought of the Proxy pattern as having 3 different flavors, but I guess that makes sense. BTW, since you almost always run out of room on your whiteboard, maybe you should rehearse what you're going to write on the board so you know how much room you need. Either that or get a bigger whiteboard. :) At my least company we used to rehearse our sprint demos the day before, so we could iron out some of the wrinkles and prepare for the questions better.

Cat tail casually wagging like a boss. Just kidding, great video, thanks!

Thanks very much for these videos and I love your cat! :)

why the board is so blurry lol even tried in 1080p, unable to watch!!!!!!(until 20:00, rest is fine)

Thanks a lot! Christopher, it is the greate explanation, which I ever heart!

Proxy 1. remote 2. virtual 3. protection & 4. smart reference ?

You very good explanation. I like it so much!

Hello Chris, I love your videos, thanks. I would like to know if you have done the one where you explain the differences between decorator, facade, adapter and proxy. I did not find it. Thanks! Awesome content!

Hi Chris, I really like this video but I am a bit confused on one point. If I understand correctly, the purpose of the Virtual Proxy is to throttle the creation of the RealSubject so that it only happens when it is needed. However, if I call GetNumPages on LazyBookParser, the BookParser will be instantiated immediately if it does not exist. Where is the throttle in this situation? Otherwise, I really have enjoyed this video and others. Looking forward to watching the rest of the playlist and will be recommending to many others!

Thank you, these videos are super informative!

I really like your videos. Thanks a lot !!! They are really helpful!

Thanks Christopher Great Explanation

Thank you Chris, for amazing tutorials. Isn't this pattern very similar to singleton pattern, except that we create object on-demand through some method instead of constructor in singleton, or am I understanding this wrong?

Nice job. I think using properties is OK though. If you chose to use a method, and then decided that you need to add a parameter, you will still need to change the callers... unless of course you use default parameters and you know that the default parameters are OK for any existing callers. My understanding is that you do not want to make your member variables public, but accessing them through properties is fine.

Your videos are fantastic and informative!

A Very very good explainer

Great video. But how could you tell if you are accessing a Field or a Method? A method always has a parentheses () and you can therefore tell that it is a method and not a field.

Perfectly explained, thank you!

Great series. What is the solution if there is an unspeakable number methods on the real service, assuming the language doesn't have a magic method.

awesome example . thanks alot!

It is a good design that you use methods acessors so that if you change it later, you will just simply change its concrete object implementing the same method interface

Awesome content, thanks

brilliant mate, keep up the good work

So, this is a way to model smart pointers(c++) ? You put an address of an object O1 in pointer(reference) and then you can wrap that pointer in another object(proxy) so that you can control access(number of accesses, protection, etc.) to O1 ? By the way, great video !

Christopher, thanks a lot, very nice explanation :)

These videos speak to my mind. If that's a good thing I don't know but I like it. It works! :D Also, give the cat some lasagna and maybe the cat will stop playing with the auto focus?

Great explanation ! just one doubt : if the proxy has a member of type real object, why does it need to inherit in interface ? in other words : what purpose exactly the interface serves ?