Why I haven’t seen your channel before. Top quality content. Looking forward to learn topics coordinators, architecture, unit tests, rxswift and anything you make :)
As few others commented, there is a slight disagreement on the use of VM. The primary purpose of all view patterns are for separating presentation logic away from business logic. So VM as the name suggests should contain only fields and logic specific to a view or set of views. The fields in VM should be subset of actual Model and logic in VM is mainly presentation oriented like formatting a date for the view or responding the change of a field in the view. The core business logic (that could include using network calls to achieve that) and full set of fields should be part of the Model.
IMO Networking can be called in the viewmodel, but the viewmodel shouldn't have actual implementation of networking. It should call some abstract services which have the networking injected. External services can fetch the model itself. Then, like you said, all the viewmodel does is convert the model to data that the view can render. So the viewmodel doesn't technically contain the networking either, and neither should the model... since the abstract service itself might be fetching the model.
As per MVVM view should not be aware about model however when you explained about protocol the closure, it was returning array of flight object to the View in this case view is dependent on model. I was explaining the exactly what you mentioned in one of the Apple interview however interviewer told me as per MVVM view should not be aware about model. What is your thought on it?
Great video as always. One question I was having is that what's the use case for the model to communicate back to the ViewModel? I understand that View Model is responsible for say making the network call and update the model but didn't come up with a use case where the model changes (without VM's involvement) and needs to communicate back to the VM.
Awesome explanation brother 👏👏. You please keep posting all videos related to Swift iOS . I have great hope that many of us get benefitted from your explanation and questions you ask in every step🙂. We need a gem like you in every learning curves😊
At 9:50 you talk about the folder structure. As an alternative I suggest keeping the 3 folders Views, viewModels and Models, while keeping the folder structure of the viewModels folder flat. Any hierarchy will be found in the Views folder and the corresponding view model for a view can be found easily. I suggest defining each view model in an extension of it's view. What do you think?
Really nice video with a lot of good points that other videos on the topic missed. I do have a few issues with it. Calling MV* patterns architecture seems wrong to me. They are patterns designed to solve a specific issue. They are not themself the architecture of the app, seeing them as architecture is what causes people to try to cram all code into one of the letters of the acronym which is not the point with the patterns, it's is also what lead to strange bastard patterns like MVC-N and MVVM-C. MV* patterns are a great tool and they do participate inf the architecture but, they are not THE architecture. Also, you talk like 100% test coverage in itself is a goal, while you should strive for good coverage, the coverage itself is not a way to measure quality as the tests cold be testing absolutely nothing.
This! I think this is why it's so hard to bring architecture as a topic on companies, because all the tutorials or learning content treats MVP or mvvm as architecture, so something like Clean Architecture becomes something that seems a theoretical ideal and people usually don't see what the point even is! Also it seems this video doesn't fully showcase dependency inversion, as it's using singletons left and right and not showing how to fully take advantage of the pattern! One could also argue that the view should not ask for the VM for data but just use the published properties, but here there's a bunch of exposed methods
May you please keep xcode version compatible with 12.4 (12D4e) in next videos, there is some people still cannot upgrade to latest version of OS/Xcode.
Can we use "Color" in ViewModel, because it needs SwiftUI to be imported in ViewModel. I have some logic related to color to be implemented in ViewModel. How can I do it without using SwiftUI in ViewModel?
Some blogs are saying we can create the view model as an extension of content view in SwiftUI and create a @State variable of view model in content view to receive the viewmodel updates. Is it a good practice ?
Hi Pallav Thank you for the wonderful videos. I have one question why did you make the protocol as type of any object? Just to use weak? If this is the case then how a struct will implement that protocol? and in case if implement then how it can be reference type? 🤯
Protocal can be use any type. By deafult they are Any. To restrict the use struct and enum. We should use anyobject. Anyobject is reference type. Then any reference make stronge recycle count to make the. weak.
Hi Great Tutorial, I have a confusion in UIKit when using MVVM and dependency injection while sending data to DetailViewController. Can you please provide me any code snippet for that. Or share link if you have any tutorial on it. Thanks in advance!
Thanks for another great video dude! You mentioned, we only keep business logic in VM. How about some other app logic such as date components, calculator formula etc? I know you also mentioned those should be a separated class but how do we call them, from VM or VC?
Those utility methods can be extensions of their classes (eg. Date), or static functions may be, so that you can directly call them without instance. Some people prefer having a singleton (say Helper) or global functions for these stuff. If you want to have an instance, you can have it injected through some method.
Excellent content, wish we had your videos earlier but nevertheless its a brilliant content.. keep on publishing videos.. Best Wishes !!! I had a query, Dependancy Injection - With help of Sw-Inject how it can be used & implemented ? Would love to have a video on the same. Many Thanks !!!!
Hi i have a question,can the viewmodel layer be reusable for multiple view layer? Or everytime you create a new view controller you always have to create the new viewmodel even though it have the same use case with the existing viewmodel file
We can test network calls by writing stubs. By creating fake URLSession, overriding resume method of URLSessionDataTask, and returning dummy response from it. I'll try covering it. Thanks for the suggestion 🙂
The whole point of SwiftUI is that it's declarative and driven by state. You shouldn't be using delegates. Also why are you creating box listeners when you're using combine?
The way you explain complex things in simpler terms is just awesome. You videos are very unique and helpful. Thanks for sharing this.
I am in search for this resource last few days. But haven’t seen here until this. Thank you!
Glad that you found the video useful 🙂
Why I haven’t seen your channel before. Top quality content. Looking forward to learn topics coordinators, architecture, unit tests, rxswift and anything you make :)
Excellent explanation, without any unnecessary details!
Best explanation I have ever heard about MVVM. You cleared all my doubts Thank you.
I just discovered your channel recently. Nothing more to say, than 11 out of 10. Really top of the line content. I appreciate your effort very much.
Thank you Ron. Glad that you liked the content 🙂
This is a very detailed video about MVVM that i think no other youtuber did. Thank you.
Brief but covered all possible questions. Easy to understand. Great explanation and great work. Thanks for this video.
As few others commented, there is a slight disagreement on the use of VM. The primary purpose of all view patterns are for separating presentation logic away from business logic. So VM as the name suggests should contain only fields and logic specific to a view or set of views. The fields in VM should be subset of actual Model and logic in VM is mainly presentation oriented like formatting a date for the view or responding the change of a field in the view. The core business logic (that could include using network calls to achieve that) and full set of fields should be part of the Model.
IMO Networking can be called in the viewmodel, but the viewmodel shouldn't have actual implementation of networking. It should call some abstract services which have the networking injected. External services can fetch the model itself. Then, like you said, all the viewmodel does is convert the model to data that the view can render. So the viewmodel doesn't technically contain the networking either, and neither should the model... since the abstract service itself might be fetching the model.
Thanks for the interesting Tutorial. You explian it in a easy and straight way.Keep it up!!. Thank you!
Top class explanation of ViewModel and Dependency Injection. I really wonder how did I miss this..
Great Video, easy and clean explanation.
very beneficial.. Thanks a lot.. Keep posting
this explains very well awesome video and thanks for clearing my concepts about dependency injection and testCases.
As per MVVM view should not be aware about model however when you explained about protocol the closure, it was returning array of flight object to the View in this case view is dependent on model.
I was explaining the exactly what you mentioned in one of the Apple interview however interviewer told me as per MVVM view should not be aware about model.
What is your thought on it?
Well explained, I really liked it the way you explained the MVVM pattern 🔥
Thanks Shashi 🙂
Superb man...loved your explaination
Top-quality contents. Carry on and help us.
Cool tut. Great work brother.
Very well Explained. Thank you
Very well explained !! Thanks
Again as always its awesome and detailed explanation :)
Thanks Puneet 🙂
Awesome video...finally gt to understand.. Thanks !!
Glad that you found it useful, thanks 🙂
awesome one so far!
very good tutorial, thank you for your explanation.
Can you also explain a comparisons and best practices between MVC, MVP and MVVM. So that we will have full clarity about Architectural Patterns..
Great video as always. One question I was having is that what's the use case for the model to communicate back to the ViewModel? I understand that View Model is responsible for say making the network call and update the model but didn't come up with a use case where the model changes (without VM's involvement) and needs to communicate back to the VM.
Awesome explanation brother 👏👏. You please keep posting all videos related to Swift iOS . I have great hope that many of us get benefitted from your explanation and questions you ask in every step🙂. We need a gem like you in every learning curves😊
At 9:50 you talk about the folder structure. As an alternative I suggest keeping the 3 folders Views, viewModels and Models, while keeping the folder structure of the viewModels folder flat. Any hierarchy will be found in the Views folder and the corresponding view model for a view can be found easily. I suggest defining each view model in an extension of it's view. What do you think?
Your videos r really helpful, thank you 🙏
So detailed explanation. Thanks for sharing
Glad that you liked the video. Thanks🙂
one of the best videos
Can you make a video on clean architecture with MVVM.
Thanks for the suggestion Sharad, I’ll try to cover it 🙂
Don’t have anything concrete on Clean as of now. I’ll let you know whenever I’ll cover it.
Great video!! Thanks
Thanks Ankit 🙂
Thank you for the informative video. Can you please create a video for implementing unit tests for API calls
thanks for this detailed explanation✌️
Thanks Akash, glad that you like it 🙂
Can you please tell us
1. how to identify when to use MVC or MVVM?
2. WhY we use MVVM over MVC?
Thanks.
Hi, it would be great if you create a video on MVVM issues on SwiftUI
Thank for the lecture . I download the project but I am not able to run it . can you please explain to run the project ?
Really nice video with a lot of good points that other videos on the topic missed. I do have a few issues with it. Calling MV* patterns architecture seems wrong to me. They are patterns designed to solve a specific issue. They are not themself the architecture of the app, seeing them as architecture is what causes people to try to cram all code into one of the letters of the acronym which is not the point with the patterns, it's is also what lead to strange bastard patterns like MVC-N and MVVM-C. MV* patterns are a great tool and they do participate inf the architecture but, they are not THE architecture. Also, you talk like 100% test coverage in itself is a goal, while you should strive for good coverage, the coverage itself is not a way to measure quality as the tests cold be testing absolutely nothing.
This!
I think this is why it's so hard to bring architecture as a topic on companies, because all the tutorials or learning content treats MVP or mvvm as architecture, so something like Clean Architecture becomes something that seems a theoretical ideal and people usually don't see what the point even is!
Also it seems this video doesn't fully showcase dependency inversion, as it's using singletons left and right and not showing how to fully take advantage of the pattern!
One could also argue that the view should not ask for the VM for data but just use the published properties, but here there's a bunch of exposed methods
Awesome explanation MAN!
BTW, the source code link was expired, could you help to check and update it?
please make a video on solid principles in swift.
May you please keep xcode version compatible with 12.4 (12D4e) in next videos, there is some people still cannot upgrade to latest version of OS/Xcode.
Can we use "Color" in ViewModel, because it needs SwiftUI to be imported in ViewModel. I have some logic related to color to be implemented in ViewModel. How can I do it without using SwiftUI in ViewModel?
Some blogs are saying we can create the view model as an extension of content view in SwiftUI and create a @State variable of view model in content view to receive the viewmodel updates. Is it a good practice ?
Great video. Please also make a video explaining the implementation of RIBs architecture aswell. Thanks in Advance.
Great video
Hi Pallav
Thank you for the wonderful videos.
I have one question why did you make the protocol as type of any object? Just to use weak?
If this is the case then how a struct will implement that protocol? and in case if implement then how it can be reference type? 🤯
Protocal can be use any type. By deafult they are Any. To restrict the use struct and enum. We should use anyobject. Anyobject is reference type. Then any reference make stronge recycle count to make the. weak.
Hi Great Tutorial, I have a confusion in UIKit when using MVVM and dependency injection while sending data to DetailViewController. Can you please provide me any code snippet for that. Or share link if you have any tutorial on it. Thanks in advance!
Thanks Pallav 👌🏻
Thanks for another great video dude! You mentioned, we only keep business logic in VM. How about some other app logic such as date components, calculator formula etc? I know you also mentioned those should be a separated class but how do we call them, from VM or VC?
Those utility methods can be extensions of their classes (eg. Date), or static functions may be, so that you can directly call them without instance. Some people prefer having a singleton (say Helper) or global functions for these stuff. If you want to have an instance, you can have it injected through some method.
Thank you bro.
Hi bro where should I use presentation logic
Excellent content, wish we had your videos earlier but nevertheless its a brilliant content.. keep on publishing videos.. Best Wishes !!!
I had a query,
Dependancy Injection - With help of Sw-Inject how it can be used & implemented ? Would love to have a video on the same.
Many Thanks !!!!
great job . Keep going.
Thanks 🙂
Thank you for the great, well explained video on MVVM and dependency injection. I am wondering if you can make a video on Apple's device check api.
Thanks!
Will you make vedio about databuilding in MVVM for us please
Thanks for the suggestion Lokesh. I'll try to cover it soon. 🙂
Thank you
Hi i have a question,can the viewmodel layer be reusable for multiple view layer? Or everytime you create a new view controller you always have to create the new viewmodel even though it have the same use case with the existing viewmodel file
One of the purposes of mvvm is to have a reusable viewmodel and model.
This is good but how to test network call?
We can test network calls by writing stubs. By creating fake URLSession, overriding resume method of URLSessionDataTask, and returning dummy response from it. I'll try covering it. Thanks for the suggestion 🙂
Pallav with your experience, I think you should make a udemy coarse targeting ios interview.
Thanks for the suggestion Pradeep. I'll look for doing that 🙂
Combine is a powerful thing, shame Apple not updating it at all.
I'm new to Combine. What needs to be updated?
Where’s the server code?
Hi Pallav, can you make a video on LLD in iOS. It would be a great help :)
Thanks for the suggestion Rajat. I’ll try covering it 🙂
1:35 struggle begins 🤭😀 🤣🤣
nice
Out of 25 mins video you explained starting 15 mins on combine and protocol. Content is good but need to concentrate on actual stuff
Business logic should be a part of the model.
The whole point of SwiftUI is that it's declarative and driven by state. You shouldn't be using delegates. Also why are you creating box listeners when you're using combine?
Thank you