You can make few optimizations : 1. Optimize the layouts - decrease the layout nesting as much as possible to increase the performance. 2. Remove one dependency (circle image view) since Glide provides an options to transform an image into circular one. 3. Avoid non-static or anonymous instances of AsyncTask - leads to memory leak. 4. Instead of NotifyDataSetChanged that will refresh the whole collection. You can just notify an item position or range that you are updating (NotifyItemInserted or NotifyItemRangeChanged). This will cause less ui calculations and drawing. Cheers!
Each time when I'm thinking about learning some new good stuff - you just upload new great video about it. Keep doing your fantastic job man, your tutorials are great!
Yet another high quality tutorial from you Mitch. I could not understand how MVVM works. The other tutorials go into details of databases and related topics. The result is MVVM basics are difficult to follow and implement. I did have to watch this tutorial five or six times to understand the MVVM concept. To test my understanding, the kotlin recyclerview tutorial (BlogPost) by you was used as a starting point. Following the instructions in this video and the source code for this tutorial, BlogPost source code was converted to the MVVM model used in this tutorial. Along the way I had to jump to google to solve problems when the intended kotlin code did not work as expected. The code I amended now works like this tutorial including adding new blogs by clicking the floating button. Many, many thanks for such a good tutorial. You are one of my go to channels for Android learning. Appreciate the time you take to post these tutorials.
Suggestion: enable "Show taps" on your emulator under developer options so the viewer can see exactly where you are pressing when you are demoing stuff.
I really like your idea to present complete examples. Many tutorials on the internet contains only fragments of the entire solution, and very often the code doesn't even compile. Very good job!
I absolutely love your tutorials. So easy to follow and understand. I love your clean and direct explanation of the topics. Great job! Thank you so much!
your video is incredible, it's my first time to deal with mvvm and all problems that have faced me, you already have put the answer for them in this video. thanks much,
Thanks for the tutorial, it was really helpful! One tiny detail you could change is that, when creating classes with the singleton pattern, the getInstance method should ideally be synchronized to avoid race conditions. Apart from that, excellent tutorial! :)
The hardest part in implementing MVVM is dealing with different data source like cache and local database and network, so your app can be useful even in situations like poor internet. I hope you use these different data sources in your upcoming tutorial
I'm going to do a rest API integration with MVVM. I'll prob add a cache too. Depends on how many members I get on my website. I can't spend too much time on a single course
Your style of teaching and the topic is very nice! But I have one issue: As far as I know the business logic doesn't belong to the viewmodels at all. In my opinion the viewmodels job is to prepare the data for the view and to route events between model and view so the view knows when the model changes and the view actions result in business logic calls on the model. That said - nice video! I did like it :)
I actually agree with you. It's best used as a "hub" to route the different business "events". That being said this is an introduction. In an actual implementation I would have repositories and other sources for data. My MVVM local database cache course is a good example. Here's the repo if your curious github.com/mitchtabian/Local-db-Cache-Retrofit-REST-API-MVVM
Other than ViewModel advantage,configuration change, what's the real benefit of using MVVM considering all the hassle and fuss involved in MVVM along with Retrofit? Assume I was to create a simple app that just makes network request using Volley without the need of worrying screen rotation, and DAO, what's the advantage we are getting for banging head learning complex architecture that can be achieved in just 10 liner code? It's no doubt good for complex projects though since it's well structured and Unit testing friendly. But what for a simple app?
The way you describe mvvm, it sounds exactly like mvc. The model is the same, the view is the same, the repository/ DAO/ data layer is the same, and the controller in MVC is a wrapper for the application's business logic. You say that the viewmodel in mvvm has the same responsibility. I am struggling to see the difference.
I just started learning MVVM so sorry if my question is stupid, at 23:49 you are making an example of what would be a server request, here you have a reference to `mIsUpdating` but is my understanding that I should have my api/db access code in the repository right? So If I make a server request on my Repository, how can I change `mIsUpdating`? I guess I could pass a reference of `mIsUpdating` to the repo but this is just me speculating I don't know if it's the best practice
I'm confused when you used Singleton Pattern, especially after reading this stackoverflow comment: "An Android Service (sub)class cannot be a singleton since the framework requires access to a default constructor for the class. The only reason I can think of for keeping a static reference to the (last) instance for which onStart was called is to simplify some internal code that may happen to reside in static methods. Considering that onStart was deprecated a long time ago (as of API level 5), this is most likely an example of bad coding style from early days of Android."
Google could have done far worse than to create an MVVM framework, but Google didn’t do anything for naming more grand than following naming as created by Microsoft for the ViewModel class, keeping in context MVVM is a Microsoft creation. Now, if only all the old Microsoft Windows GUI applications were self-consistent for how they were architected for the GUI code versus the rest, with keeping it separated...
I dont understand how the list in the adapter automatically changed. We just call notifydatasetchanged(), but doesn't add the new value to the list in adapter. But somehow when the list in livedata is updated, the list in adapter is updated too. How that's work? The list in adapter is just normal list and we doesn't update it too..
Hey Mitch, I am a fan of your tutorials! One question to you for this tutorial: is it a good way to make the repository as a singleton? If that is the way, the singleton instance will be always alive and the livedata inside won't ever be released. I know this makes sense to the demo scenario because it is pure a places app hence we expect the data to be alive for ever. however I think you can explain a little bit for the cases sometimes we don't want to make the repository as singleton, and it should be bind to the lifecycle owner? Just my 2 cents, I am a rookie to Android, especially to LiveData(Jetpack).
If only the MutableLiveData objects can change and I understand you can "observe" those changes, why would the regular LiveData have the observe method, if it does not change. Are we always supposed to use the MutableLiveData?
Mitch, why do we need to use postValue(), Instead you should have used setValue() itself, Since onpostexecute runs on the Main thread, setValue should be good enough right? please correct me if my understanding as wrong.
I have found a bug. Each time the app is restarted the dataSet is duplicated. To avoid this I have added dataSet.clear(); in the method setNicePlaces() Do you noticed this also? Why the array is saved?
Line 46 (28:24) - you are getting back the new list from the viewmodel everytime the observer knows about a change but you do nothing with the new list that you receive - so why bother notifying the adapter for any changes as you do nothing with these changes anyway?
Great work Mitch. But i have one doubt as per understanding ViewModel data should clear when we click back button in the mobile and activity is destoryed Right. Iam trying to reopen the app then recycler view Items going on increase. Is there any leak the program.
Awesome video , great Job my friend. Thanks for your smooth English and great explanation, I was really frustrated by Indian videos out there.. glg lglgl gl
They represent different ways to structure your code. MVC, MVP, MVVM. They all have different advantages/disadvantages. But personally I like MVVM for the reasons discussed in this video.
@@codingwithmitch I have seen MVP is used to make test driven development which widen the scope for JUNIT testing , but I never saw MVVM being used for test driven development. So my question is whether MVVM can also be used for TDD ?
I just done your demo example , it so simple i understood the concept cleanly . But when i tried to implement this with my Database related app its hard to handle , didn't work in my case. I have to minimize app and then reopen it then i see changes. Just waiting for you MVVM Retrofit tutorial to understood it clearly. Thanks for all.
I have a question here, it's about ViewModel. Should I have ViewModel per screen or per entity or per business module? For example, I have a user authentication module in my app(login/signup) and then profile page and dashboard page that shows user information. Now, should I create one single ViewModel that gives me all necessary methods like login, signup, logout, getUserDetails or should I have multiple like LoginPageViewModel (having only login method), SignUpPageViewModel (having only signup method), ProfilePageViewModel (having only getUserDetails) and so on? Also, if a page requires multiple objects like Users and Bookings then what? Should one ViewModel has both the getters or should I have 2 different ViewModels like DashboardUserViewModel and DashboardBookingsViewModels.
Thank you for the movie. One important comment: new nicePlace is added in MainActivityViewModel (and not in NicePlaceRepository). I would like to see how to run postValue from the NivePlaceRepository. Thank you.
Hey Mitch, with repositories, am I supposed to make a single repository for all network operations on my app or multiple repositories with network operations that are relevant to each other?
Sorry I didn't see this comment until now. I would make different repositories to keep it organized. Example: Suppose you had to query "User" account data and also "News" feed data from a server. I would make two repositories. UserRepository and NewsRepository. Each repository would contain all the methods for managing the data from the server.
Hey Mitch, i ve a question, why did you used different packages for classes in it. They could have been in one package. How does it help ? Thanks in advance
Hey Mitch! There's a problem. If I actually call an online API in setNicePlaces() method in Repository class, and set the value of dataset in the onResponse(), the LiveData doesn't update the UI with the received data. How should that be implemented? Please help !!!!
Using LiveData in repository seems like a memory leak. Even if activity that was using that data is finished, the last value is stuck in LiveData in a singleton class (repo) until the app process is killed. Repository may return heavy objects and in a big app you can get a lot of RAM wasted this way...
@@ZubayerAhmed Do not keep an instance of the data (the 'dataset' private field in the video) inside the repository class. When the user calls 'getDataset()' (in the example of the video, 'getNicePlaces()'), you get all the data from whatever source you are dealing with, wrap it in the appropriate class, and return it to the user.
Do we have to use live data if we are using viewmodel and mvvm ? Like I have some values of user name, address, age etc.. so how to store and retrieve them using viewmodel and mvvm ?
Change: mViewModel = ViewModelProviders.of(this).get(MainActivityViewModel.class); To: mViewModel = new ViewModelProvider(this).get(MainActivityViewModel.class);
hello mitch i was trying to fetch the data from firebase database using MVVM and following this lecture but it is not working,at the end mutableLivedata showing null,
You can make few optimizations :
1. Optimize the layouts - decrease the layout nesting as much as possible to increase the performance.
2. Remove one dependency (circle image view) since Glide provides an options to transform an image into circular one.
3. Avoid non-static or anonymous instances of AsyncTask - leads to memory leak.
4. Instead of NotifyDataSetChanged that will refresh the whole collection. You can just notify an item position or range that you are updating (NotifyItemInserted or NotifyItemRangeChanged). This will cause less ui calculations and drawing.
Cheers!
wow didn't knew there was notifyiteminserted or notifyitemchanged till now been almost 8 months in android thanks man
Any sources/references on how to use Glide to transform an image into a circular one?
For AsyncTask, it's better to give weak reference using interfaces rather than using non-static instances
@@arpitkumar4525 Glide.with(context)
.load(url)
.apply(RequestOptions.circleCropTransform())
.into(imageView);
@@ritvijsaxena7201 How would one achieve point 3)? Even the JSONObjectRequest class from Android uses anonymous instances/lambdas.
Each time when I'm thinking about learning some new good stuff - you just upload new great video about it. Keep doing your fantastic job man, your tutorials are great!
Yet another high quality tutorial from you Mitch. I could not understand how MVVM works. The other tutorials go into details of databases and related topics. The result is MVVM basics are difficult to follow and implement. I did have to watch this tutorial five or six times to understand the MVVM concept. To test my understanding, the kotlin recyclerview tutorial (BlogPost) by you was used as a starting point. Following the instructions in this video and the source code for this tutorial, BlogPost source code was converted to the MVVM model used in this tutorial. Along the way I had to jump to google to solve problems when the intended kotlin code did not work as expected. The code I amended now works like this tutorial including adding new blogs by clicking the floating button. Many, many thanks for such a good tutorial. You are one of my go to channels for Android learning. Appreciate the time you take to post these tutorials.
Logically clear, and it helps me understand MVVM better (Also the English speech is relatively easy so I can get your point well).
GOOD TUTORIAL.
So far the only tutorial on MVVM i eventually got working... i understood it better after watching this tutorial... thank you...
Finally found an awesome Android teacher .
Suggestion: enable "Show taps" on your emulator under developer options so the viewer can see exactly where you are pressing when you are demoing stuff.
I really like your idea to present complete examples. Many tutorials on the internet contains only fragments of the entire solution, and very often the code doesn't even compile. Very good job!
The best video for the beginners to understand the MVVM. Thank you
Wow, just wow, I can't even begin to explain how you've inspired me. Thank you. :)
Very good explanation and example, you used a simple problem to explain about live data with MVVM arch, congrats.
watched a lots of videos for mvvm but finally this one really taught me something thank you sir awesome explanation.
I absolutely love your tutorials. So easy to follow and understand. I love your clean and direct explanation of the topics. Great job! Thank you so much!
I also learned that if you need the application context in your viewmodel, just extend Androidviewmodel instead of ViewModel
Couldn't that lead to memory leaks? The whole point with the ViewModel is to avoid Context all together.
your video is incredible, it's my first time to deal with mvvm and all problems that have faced me, you already have put the answer for them in this video. thanks much,
Just applied your example to my app, and it works. Thank you!
I'm a big fan of your tutorials man, keep up with the good work !! (Y)
All courses should teach using the best practices
Look at that I implemented viewmodel into my app last night and this afternoon I see your video!
Hey Mitch, you’re doing a great job!
I’m sure with time you’ll have a ton of subscribers and views.
maaaan you just took a complicated subject and made it simple
thank you!!
Thanks for the tutorial, it was really helpful! One tiny detail you could change is that, when creating classes with the singleton pattern, the getInstance method should ideally be synchronized to avoid race conditions. Apart from that, excellent tutorial! :)
Great explanation. First minute watched and i know what its about. Havent seen any better explanation than that.
Thanks for tutorial , you have explained Android MVVM way easier than other tutorials on youtube.
Watch this next for a much better mvvm example codingwithmitch.com/courses/rest-api-mvvm-retrofit2/
After trying for about months ,I think finally got this!Thank you~!
The hardest part in implementing MVVM is dealing with different data source like cache and local database and network, so your app can be useful even in situations like poor internet. I hope you use these different data sources in your upcoming tutorial
I'm going to do a rest API integration with MVVM. I'll prob add a cache too. Depends on how many members I get on my website. I can't spend too much time on a single course
Most simple tutorial ever seen bro, Thank you very much. U helped me lot
You are creating really awsome content. We can feel that you are really putting your heart into it. I really really thank you. best of luck
This helped a lot in my understanding of MVVM. Hopefully I can build my own viewmodel soon
Awesome. Using your vids for my bachelor thesis.!!! thank you
much appreciated i always love your work man! you are a legend.
CONGRATS ON 30K my man!
I'm more of a MCVMPICVVM guy? It basically takes 2 years to write a simple app, but, it's worth the wait!
So glad I stumbled upon your tutorials! Thanks man!
Waiting so bad for your rest api + MVVM Project!!
The best Viewmodel video you can find, end!
Thank you for your clear and step by step explanation !
Your style of teaching and the topic is very nice!
But I have one issue: As far as I know the business logic doesn't belong to the viewmodels at all. In my opinion the viewmodels job is to prepare the data for the view and to route events between model and view so the view knows when the model changes and the view actions result in business logic calls on the model.
That said - nice video! I did like it :)
I actually agree with you. It's best used as a "hub" to route the different business "events".
That being said this is an introduction. In an actual implementation I would have repositories and other sources for data.
My MVVM local database cache course is a good example. Here's the repo if your curious github.com/mitchtabian/Local-db-Cache-Retrofit-REST-API-MVVM
.. th-cam.com/video/Y5ys6chK_wI/w-d-xo.html
Other than ViewModel advantage,configuration change, what's the real
benefit of using MVVM considering all the hassle and fuss involved in
MVVM along with Retrofit?
Assume I was to create a simple app that
just makes network request using Volley without the need of worrying
screen rotation, and DAO, what's the advantage we are getting for
banging head learning complex architecture that can be achieved in just
10 liner code? It's no doubt good for complex projects though since it's
well structured and Unit testing friendly. But what for a simple app?
Thats good info u are give to the world for free ... big love
Thanks for the demo of MVVM
Liked it a lot
thanks for that video, it was exactly what I was looking for. Excited for MVVM now :)
Really nice and well explained tutorial, notice that "ViewModelProviders" has been deprecated and now have to use "ViewModelProvider"only :)
This video is old
Glad I stumbled upon this. Great explanation!
Please continue this topic to adavance..🙏🖤
thank you, this is awesome. really eazy to follow and focus to the important point
you should also make the default constructor of NicePlaceRepository class private. in order to implement the proper singleton method.
Yes you're right
Hello i am from India, You are Amazing brother, Thank you...
Thanks
Thanks man. Very clear explanation.
Thank you for explaining difference mutablelivedata vs livedata. I am very confused when to used both of them because they are basically almost same.
dudee...Just excellent this is really what i want
The way you describe mvvm, it sounds exactly like mvc. The model is the same, the view is the same, the repository/ DAO/ data layer is the same, and the controller in MVC is a wrapper for the application's business logic. You say that the viewmodel in mvvm has the same responsibility. I am struggling to see the difference.
I just started learning MVVM so sorry if my question is stupid, at 23:49 you are making an example of what would be a server request, here you have a reference to `mIsUpdating` but is my understanding that I should have my api/db access code in the repository right? So If I make a server request on my Repository, how can I change `mIsUpdating`?
I guess I could pass a reference of `mIsUpdating` to the repo but this is just me speculating I don't know if it's the best practice
I'm confused when you used Singleton Pattern, especially after reading this stackoverflow comment:
"An Android Service (sub)class cannot be a singleton since the framework requires access to a default constructor for the class. The only reason I can think of for keeping a static reference to the (last) instance for which onStart was called is to simplify some internal code that may happen to reside in static methods.
Considering that onStart was deprecated a long time ago (as of API level 5), this is most likely an example of bad coding style from early days of Android."
Google could have done far worse than to create an MVVM framework, but Google didn’t do anything for naming more grand than following naming as created by Microsoft for the ViewModel class, keeping in context MVVM is a Microsoft creation.
Now, if only all the old Microsoft Windows GUI applications were self-consistent for how they were architected for the GUI code versus the rest, with keeping it separated...
I dont understand how the list in the adapter automatically changed. We just call notifydatasetchanged(), but doesn't add the new value to the list in adapter. But somehow when the list in livedata is updated, the list in adapter is updated too. How that's work? The list in adapter is just normal list and we doesn't update it too..
This one is awesome tutorial........ Please add local cache and retrofit both in your next tutorial..
Here it is: codingwithmitch.com/courses/android-local-database-cache-rest-api/
Hey Mitch, I am a fan of your tutorials! One question to you for this tutorial: is it a good way to make the repository as a singleton? If that is the way, the singleton instance will be always alive and the livedata inside won't ever be released. I know this makes sense to the demo scenario because it is pure a places app hence we expect the data to be alive for ever. however I think you can explain a little bit for the cases sometimes we don't want to make the repository as singleton, and it should be bind to the lifecycle owner? Just my 2 cents, I am a rookie to Android, especially to LiveData(Jetpack).
If only the MutableLiveData objects can change and I understand you can "observe" those changes, why would the regular LiveData have the observe method, if it does not change. Are we always supposed to use the MutableLiveData?
Add imageview inside card view and give card view radius of half of it's height and it will be circular imageview
Great video as always, and nice teaching keep it up!
Mitch, why do we need to use postValue(), Instead you should have used setValue() itself, Since onpostexecute runs on the Main thread, setValue should be good enough right? please correct me if my understanding as wrong.
Excellent explanation! Thanks
It was great. 🙏
and, so helpful. 🙏
Thanks, Dear Mitch
your video is very helpful and well thought out
5:57 The user is a datasource,too. Activity/Fragment editText.getText.toString is data.The user of the app is ALWAYS a Datasource
Loved the tutorial but I couldn't stop looking at the misspelling of Australia in the recycler app 😂
I have found a bug. Each time the app is restarted the dataSet is duplicated. To avoid this I have added dataSet.clear(); in the method setNicePlaces()
Do you noticed this also? Why the array is saved?
Line 46 (28:24) - you are getting back the new list from the viewmodel everytime the observer knows about a change but you do nothing with the new list that you receive - so why bother notifying the adapter for any changes as you do nothing with these changes anyway?
Great work Mitch.
But i have one doubt as per understanding ViewModel data should clear when we click back button in the mobile and activity is destoryed Right. Iam trying to reopen the app then recycler view Items going on increase. Is there any leak the program.
Great video. I'm gonna have to rewatch it a few times though. As someone new to design patterns it was hard to follow.
These are interesting tutorials. The Java is a little odd to follow, though. Are you going to make versions of these videos in Kotlin?
I am still confuse with the adapter you have not used data binding in the xml of recyclerView item
whaaaaaaaaaaat !!!! i made the right decision subscribing you man !!!!
Awesome video , great Job my friend. Thanks for your smooth English and great explanation, I was really frustrated by Indian videos out there.. glg lglgl gl
Yes I need this right now :) Please more
That sounds so great.
What are the differences between various Android architectures?
What is the proper ways to use them?
They represent different ways to structure your code. MVC, MVP, MVVM. They all have different advantages/disadvantages. But personally I like MVVM for the reasons discussed in this video.
@@codingwithmitch thank you so much sir.
MVP - addressed separation on concerns
MVVM - addressed data persistence that was lacked in MVP
@@theonlyarjun good way to put it
@@codingwithmitch I have seen MVP is used to make test driven development which widen the scope for JUNIT testing , but I never saw MVVM being used for test driven development. So my question is whether MVVM can also be used for TDD ?
I just done your demo example , it so simple i understood the concept cleanly . But when i tried to implement this with my Database related app its hard to handle , didn't work in my case. I have to minimize app and then reopen it then i see changes.
Just waiting for you MVVM Retrofit tutorial to understood it clearly. Thanks for all.
It's published codingwithmitch.com/courses/rest-api-mvvm-retrofit2/
I have a question here, it's about ViewModel. Should I have ViewModel per screen or per entity or per business module? For example, I have a user authentication module in my app(login/signup) and then profile page and dashboard page that shows user information. Now, should I create one single ViewModel that gives me all necessary methods like login, signup, logout, getUserDetails or should I have multiple like LoginPageViewModel (having only login method), SignUpPageViewModel (having only signup method), ProfilePageViewModel (having only getUserDetails) and so on?
Also, if a page requires multiple objects like Users and Bookings then what? Should one ViewModel has both the getters or should I have 2 different ViewModels like DashboardUserViewModel and DashboardBookingsViewModels.
The same question....
Thank you for the movie. One important comment: new nicePlace is added in MainActivityViewModel (and not in NicePlaceRepository). I would like to see how to run postValue from the NivePlaceRepository. Thank you.
Please use the dark theme for your IDE... very hard to watch the video during the night
Good video! But Android team didn’t come up with the name view model, Microsoft did lol
Can you still tell me any reason to chose MVP over MVVM?
.. th-cam.com/video/Y5ys6chK_wI/w-d-xo.html
Thanks again mitch!!
Thank you so much, this was more than helpful!
thank u for this tutorial. I have a question. If I want to update 'mIsUpdating' variable from the repository, what is the recommended way to do it?
Hey Mitch, with repositories, am I supposed to make a single repository for all network operations on my app or multiple repositories with network operations that are relevant to each other?
Sorry I didn't see this comment until now.
I would make different repositories to keep it organized.
Example:
Suppose you had to query "User" account data and also "News" feed data from a server. I would make two repositories. UserRepository and NewsRepository. Each repository would contain all the methods for managing the data from the server.
@@codingwithmitch thanks for replying! Makes sense. That's what I have been doing so far
Hey Mitch, i ve a question, why did you used different packages for classes in it. They could have been in one package. How does it help ? Thanks in advance
Is mAdapter != null in 46 row inside your activity? U init mAdapter only in 50 row....
Pretty awesome work.
Hey Mitch! There's a problem. If I actually call an online API in setNicePlaces() method in Repository class, and set the value of dataset in the onResponse(), the LiveData doesn't update the UI with the received data. How should that be implemented? Please help !!!!
Using LiveData in repository seems like a memory leak. Even if activity that was using that data is finished, the last value is stuck in LiveData in a singleton class (repo) until the app process is killed. Repository may return heavy objects and in a big app you can get a lot of RAM wasted this way...
Can you suggest what will be the exact implementation to avoid memory leak, I'm new to this
@@ZubayerAhmed Do not keep an instance of the data (the 'dataset' private field in the video) inside the repository class.
When the user calls 'getDataset()' (in the example of the video, 'getNicePlaces()'), you get all the data from whatever source you are dealing with, wrap it in the appropriate class, and return it to the user.
Do we have to use live data if we are using viewmodel and mvvm ? Like I have some values of user name, address, age etc.. so how to store and retrieve them using viewmodel and mvvm ?
Does data get automatically updated in the app when its updated on the server or we have to call api again to get the latest data from server?
Nicely explained, thanks!
Thank you.
thanks mitch, love it
You should watch the full course, you'll really love that. codingwithmitch.com/courses/rest-api-mvvm-retrofit2/
@@codingwithmitch of course mitch ;)
ViewModelProviders.of(context) is deprecated..what to use instead
Change:
mViewModel = ViewModelProviders.of(this).get(MainActivityViewModel.class);
To:
mViewModel = new ViewModelProvider(this).get(MainActivityViewModel.class);
Very good explanation
hello mitch i was trying to fetch the data from firebase database using MVVM and following this lecture but it is not working,at the end mutableLivedata showing null,