Proxy Pattern - Design Patterns (ep 10)

[@eahmedshendy]

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

[@Icecrax]

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!

[@vipram91]

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

[@ChristopherOkhravi]

Hehehehe 😁😁

[@caoinismyname]

It really was someTHING! 😂

[@safvanp567]

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.

[@VictorQianYT]

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

[@GamerForeverChannel]

I cant see a thing

[@diego99799]

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

[@ChristopherOkhravi]

Thank you very much. That makes me happy to hear. I wish I could deliver more and faster. Gotta keep the balance with my day job :) But as I get the flow up I will hopefully be able to. Thank you very much for watching :)

[@emersontavera9362]

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.

[@frogspawn8]

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!

[@ewelinap491]

i've seen he is a proffessor for 8 years now ;)

[@davidegiancane4159]

The best Design Pattern playlist on KZbin! 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!

[@SGTR32]

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!

[@KenZhi-lk9qw]

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

[@ratulmahjabin9765]

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!

[@AmitSharma-vh7qv]

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

[@kiwalok8982]

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.

[@glebcherkashyn2357]

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

[@emmanuelasunomeh9949]

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.

[@Rappomon]

We need more people like you! Everything I search on KZbin 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!

[@Rappomon]

They could be a little shorter tho :D

[@Elenthiriel]

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

[@HarithAldabbagh]

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

[@arpitamandal1472]

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

[@startrek3779]

Excellent explanation! Thank you so much!

[@onurodabas8207]

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 :)

[@DailyStoicStepsOfficial]

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

[@mikhailbisserov8017]

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

[@crashedbboy]

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

[@nadnerb2178]

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.

[@rajsekharmahapatro]

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

[@SaurabhGuptaicecool]

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

[@97Patok]

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

[@christianlevesque9017]

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

[@pradeepsanju]

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

[@ChristopherOkhravi]

+pradeepsanju Glad to hear! I will. Thank you for the encouragement and thank you for watching :)

[@hazemgharib]

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

[@heisenburger311]

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!

[@ChristopherOkhravi]

Hah! :D :D :D

[@david44707]

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

[@dnyaneshbarkade538]

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

[@ChristopherOkhravi]

Haha thanks! I'm glad to hear :) Actually there are two cats but one of them seems to always be around when the camera is out :D Thanks for watching :)

[@mil3761]

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

[@aneeshjain3395]

Instead of book I prefer to watch this playlist again xD

[@utkarshgupta2909]

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

[@pietrodellanotte]

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!

[@shaunsmith8762]

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!!!

[@melbinthomas2199]

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

[@mathiasyeremiaaryadi9097]

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

[@andyk2181]

As an example, if you had a coordinate class then you would have methods getX() and getY(), but you could also have getMagnitude() and getAngle(), how the data was store, either in cartesian or polar coordinates, would be unknown to anyone using the class - in fact you could change it without affecting the public interface.

[@shankar7435]

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

[@dhananjaypal8498]

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

[@PA-vf5st]

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....

[@zahidkhankhan]

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

[@konzinovmaverick4539]

Someone would say ANOTHER ONE! Great Job Dude!

[@ChristopherOkhravi]

+konzinov maverick Yeeeeeeea they don't wanna see us win!

[@somunix]

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.. :)

[@michor10]

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!

[@EminoMeneko]

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.

[@alirezajazayerei2881]

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

[@CheapNLazyAdventures]

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.

[@swapnilkhole]

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!

[@mahmoudashraf117]

awesome example . thanks alot!

[@KirubaEbenezer]

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 KZbin star. People from India simply love Liza koshy. So they will love you too…...

[@ChristopherOkhravi]

Haha I’m sorry that I kept you up all night but I’m glad to hear you found the videos engaging! :) And I assume it was worth it since you stuck with it 😀 Thank you very very much for the encouragement and great suggestion. I will try my best! 😄😄

[@arvindeya]

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.

[@VishnuRadhakrishnaPillai]

Thanks Christopher Great Explanation

[@sailakshmimanthena4244]

you really helped me during my exams. thanks bro

[@petschi3473]

great! Thank you!

[@leonarddacosta7710]

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.

[@shepherd2436]

27:33 cute cat!!!

[@tonydunne1965]

A Very very good explainer

[@ericchou6503]

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

[@oeurnravuth9078]

You very good explanation. I like it so much!

[@ChristopherOkhravi]

Thanks! And thanks for watching :)

[@jordanshuriken]

Your videos are fantastic and informative!

[@lpatrasco]

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.

[@TheAlphaThug]

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

[@Levendo]

Thank you, these videos are super informative!

[@KratosKaiBia]

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

[@davidegiancane4159]

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

[@stanislavmachel5361]

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

[@martonkaable]

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

[@ChristopherOkhravi]

Awesome. I’m glad to hear :) Welcome :)

[@nemanjastankovic941]

Thanks a lot for this amazing explanation 🤓

[@Cheagong]

Perfectly explained, thank you!

[@domidodongo]

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

[@Blaskillo]

Awesome content, thanks

[@crankitsourav8686]

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 ??

[@ArjonJasonCastro]

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

[@stanverdiesen3334]

Nice video and still relevant. I do think it would be good if you emphasize that you make a trade off in 'execution' performance. You proposed solution would require a lot of memory in order to have a fast initial execution. (I presume that when the book metrics are determined, the book string is removed from the memory in the parser. ) I understand this is a example that might never happen, but I think that in most cases there will be a similar trade off which should be considered carefully. For the rest, love your videos!

[@igorlopatchin904]

Amazing video, thank you very much

[@Cezinha0Gusto]

Congratulations and thaks to share!

[@amank2410]

Nice explanation Christopher !

[@ChristopherOkhravi]

+Amann Thank you. I'm glad to hear it's useful. And thank you for watching :)

Again nice explanation. Thank you for share your knowledge :)

[@anjanishrivastava1273]

outstanding...I am great fan of you

[@ryanrichard4805]

Great video. Very informative.

[@oleksandr.pastukhov]

Christopher, thanks a lot, very nice explanation :)

[@ChristopherOkhravi]

And thank *you* for watching :)

[@amirrazaahad4576]

thanks a ton for this amazing video.................

[@masterbonzala]

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

[@kirillzlobin7135]

11:30 in JS there is a such thing, when you use getters it lloks like you are accessing a property, but in reality you can call a method in this moment.

[@tjgawhane]

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

[@frueskens]

you should use a thread save singleton in order to create the real book parser

[@moodyfilms4]

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!

[@jhon3991]

@Christopher Okhravi I am suprised that in the proxy class there is no member variable to record the result to avoid do the same caculation twice.

[@imedboufares2422]

Good explanation MAN , thank you

[@yahyadurrani5482]

brilliant mate, keep up the good work

[@JATR1X]

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.

[@ankitavyas7996]

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?

[@pradeep422]

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

[@AlexandreBlascoBraso]

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!

[@ChristopherOkhravi]

Episode 12 in the playlist 😊 Thanks for watching. kzbin.info/www/bejne/ooHWhH9slJyBeMk

[@AlexandreBlascoBraso]

Thanks I will take a look!@@ChristopherOkhravi

[@vi3ruSak]

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 !

[@narendrasinghrathore1012]

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