Get value from mutablelivedata. I could not find documentation for same.

Get value from mutablelivedata None of the following work Jun 8, 2019 · Consider the following ways to expose MutableLiveData: Method A class ThisViewModel : ViewModel() { private val _someData = MutableLiveData(true) val someData: LiveData&lt;Boolean&gt; Apr 12, 2020 · It is not intuitive to set the value but get the LiveData with the value in it. If I were doing it the first way, I’d name the function “update” instead of “get” since the function isn’t directly returning something, but rather is updating the LiveData with the most put to date Dec 9, 2024 · A quick tutorial on the differences between the value property and emit function of a MutableStateFlow in Kotlin. postValue (selectedSender), _receiverListItems should be notified of that change. If you add an observer, it will get a value once the observer has triggered once. La clase MutableLiveData expone los métodos setValue(T) y postValue(T) de forma pública; debes usarlos si necesitas editar el valor almacenado en un objeto LiveData. Here’s how it works: Define LiveData in ViewModel: class MyViewModel : ViewModel() { val liveData = MutableLiveData<String>() } 2. Sep 9, 2017 · Although what I did was to subclass LiveData and have a private inner MutableLiveData so there is no way that any outside classes can change the value of my LiveData to null. Oct 10, 2022 · _error. Feb 10, 2025 · The value "b" would be set at first and later the main thread would override it with the value "a". user - MutableLiveData does not observe whatever object you pass as initial value to its public constructor The value observed is MutableLiveData. If I set up an onClick () in the main activity to respond to a button click I can get the onObserver () to run and display data that I set in the onClick (). Transformations/MediatorLiveData: Use these when you need to perform transformations or merge Mar 25, 2022 · I am calling an increaseCount(id: String) method from a composable to increase the value of a parameter in a LiveData List of objects. value property to update its content, and similarly, MutableStateFlow also allows value updates directly through its . LiveData is a handy Apr 14, 2020 · In Android Kotlin Fundamentals, the code mentions of using a backing property to encapsulate the MutableLiveData in ViewModel so that only the ViewModel itself can change said mutable value. Feb 3, 2024 · MutableLiveData: Opt for MutableLiveData when you need to modify the value within the ViewModel. But in a specific case I want to add an item. I need to add an element to the first position of the array and tried with &quot Feb 20, 2021 · I am trying to get an object from a MutableLiveData<Resource<ObjectIWant>> to a var hereIwantTheObject : ObjectIWant in my HomeFragment, apparently use the Resource class is the recomme private var _studentsTemp = MutableLiveData<MutableList<Student>>() val studentsTemp: LiveData<MutableList<Student>> get() = _studentsTemp init { _studentsTemp. when ViewModel is created i. This is a problem with the test environment setup as @CommonsWare suggested in his comments earlier in this . 0-alpha01' It's a shame they haven't updated MediatorLiveData to reflect that, though. You'd have to cast it to LiveData, which you could be done with a backing property. That is if you need to update yourself the value, but in this case Room takes care of that. Jun 4, 2017 · Room always returns Null value while using LiveData but returns proper value when we are not wrapping the value with live data. valueOf (l/1000)); without ever instanstiating the liveData Change this MutableLiveData<String> liveData; to MutableLiveData<String> liveData = new MutableLiveData<> (); – blongho CommentedSep 2, 2021 at 9:14 Apr 30, 2019 · The main difference between LiveData and MutableLiveData is: you can change the value of MutableLiveData but LiveData does not allow you to change it's value LiveData only allows you to observe its value. As we can see in the diagram, the ViewModel and inner layers don't differ. MutableLiveData is a LiveData subclass that allows value modification using setValue(T) or postValue(T), commonly utilized in ViewModel for observer interactions. form Jun 21, 2018 · Binding is what you do at the beginning to gather the MutableLiveData (what you are doing in loadData), but after you've done that once you shouldn't do it again. Jun 11, 2022 · I don't quite understand the behavior of MutableLiveData or I can't find the proper documentation. Kindly help us to resolve this. Feb 24, 2021 · val selectedLiveData by lazy { MutableLiveData<List<Core>>() } I don't want to trigger the observers so I am not assigning the value as I just want to remove a single element from the liveData list and only trigger when adding. We need this class because it makes it easier to handle the data inside View … Feb 10, 2025 · The value "b" would be set at first and later the main thread would override it with the value "a". MutableLiveData. value = getAddressList() } return AddressList } but I get the following error: IllegalStateException: Cannot invoke setValue on a background thread Is there a way to make it work with coroutines? Jan 24, 2022 · I wrote the following MediatorLiveData class that takes a list of LiveData objects and watches them all for changes, then applies a given function to compute the summary each time a value changes: MutableLiveData in Android architecture plays a crucial role in managing UI-related data in a lifecycle-conscious way. Why is the mutablelivedata retaining its old value even after the observer activity is destroyed? However, every time I need to change a single value of class to trigger Livedata to notify a fragment, I need to tediously get previous value of a class stored in LiveData and then change a value in that class, and than update whole LiveData. Jun 5, 2020 · private var itemMutableList: MutableLiveData<List<ItemItem>> = MutableLiveData() Now in your response function assign value to it: Dec 14, 2023 · MutableLiveData: Exposes methods like setValue, postValue, and getValue to modify the value. postValue(null) //Error Cannot set non-nullable LiveData value to null [NullSafeMutableLiveData] parameter String of _error is obviously nullable, am I doing something wrong? Nov 16, 2019 · When you enter two values and then press the plus button then result will be visible. It is not intuitive to get first then only follow by set, but that’s the way preferred. You can vote up the ones you like or vote down the ones you don't like, and go to the original project or source file by following the links above each example. map { it * 0 Jun 12, 2020 · It's not clear from the code that a value ever will be set on cachedResendOtpResponse, since we don't know exactly what OtpUseCase. selectedSkillPoints. However, when I log the value of the _sender, I get null. Dec 13, 2018 · val myVariable = MutableLiveData<ArrayList<String>>() Well, now you only have to pass the constructor of the empty list within the type parentheses so that your variable does not remain with a Null value. Seems to me like you could do the same thing with just a private MutableLiveData for the Contact ID string, and a public Transformations. How can I ensure that after updating a single field in class, I would update whole LiveData object? Dec 22, 2017 · I need to get an Observer event when the item is added to the List of LiveData. This is where we can take the help of LiveData, to automatically update the view whenever there is any change in data. Following swim-lane diagram explains the overview of the data flow. The following examples show how to use androidx. Jun 19, 2020 · if you want to get User then sure, but if you want to get LiveData<User> to display stuff suspend is not necessary You can actually "await" for live data inside coroutine it is a workaround, there might be better options: Feb 10, 2025 · The MutableLiveData class exposes the setValue(T) and postValue(T) methods publicly and you must use these if you need to edit the value stored in a LiveData object. MutableLiveData value get cleared when try to filter data from its value too frequently Asked 4 years, 7 months ago Modified 4 years, 7 months ago Viewed 90 times Aug 29, 2019 · I tried writing a helper class like so that uses an underlying MediatorLiveData to set the value, but it looks like my onChanged callback is never called: class MutableLiveDataWithInitialValue<T> extends MutableLiveData<T> { Dec 26, 2021 · This is just an initial value for the MutableLiveData object, but MutableLiveData is not observing currentUser nor Datasource. when init block runs in View Model. Object)' on a null object reference Asked 7 years, 2 months ago In your current code, any external class can modify the score and word variables using the value property, for example using viewModel. So, let's get started. Jul 18, 2021 · com. However, when I test the code to see that the value has actually been assigned, the test fails stating that the value is null. 1 value/sec) and we don't have to wait for all 5 values to get returned to us as a result. Observers in Fragments: class MyFragment : Fragment() { private lateinit var MutableLiveData You can use LiveData independently from Room, but to do so you must manage data updates. Oct 30, 2019 · Finally, I could understand what's causing the exception. To do this, I used toMutab Dec 27, 2024 · Jetpack Compose simplifies UI creation, but integrating it with MVVM (Model-View-ViewModel) architecture involves changes compared to XML-based systems. As workaround I can create another entity (POJO class) without LiveData and use it for validation. value. This is synchronous update where main thread calls setValue. The document says that the page will only be updated when the value of State changes. postValue(true) foo. How to do the same with MutableStateFlow that became a modern alternative to it? Currently I made a workable work-around but it has a cascade design and boilerplate code. Oct 19, 2021 · You could just return List<CategoriesModel> from your repository. But I need help. But as far as I understand the event receives only when I replace the old list with a new one. Jun 23, 2024 · LiveData vs MutableStateFlow in Android Kotlin: A Comprehensive Comparison In Android development, managing state and handling data changes efficiently is crucial for building responsive and Oct 22, 2018 · This is all nice, but be aware! val foo = MutableLiveData<Boolean>() // this foo. MVVM LiveData Data Binding Up until now, we’ve used Data Binding to update the View from the ViewModel. lifecycle:lifecycle-extensions:2. i cannot get the data to the onObserver () in my main activity. Because I used to get it from the list and could do Sep 10, 2020 · Initially, the value the LiveData holds for bonusNumber is 1 as it should be (based on the init block), but when the button is pressed to display a random number 0 is displayed after the button is pressed to generate the random number, instead of an actual random number between 1 and whatever the user entered in the EditText. LiveData does not have a value unless it has an observer. launch { AddressList. It inherits from LiveData and provides methods like setValue() and postValue() to update the data. @Suppress("UNCHECKED_CAST") Jun 21, 2024 · Example: Updating 100 Observers Imagine you have 100 fragments observing the same LiveData. They are usually used together. Feb 6, 2023 · So, using flows we can get each value after it is ready to be emitted (i. You may check out the related API usage on the sidebar. Sample untested ViewModel code: Jan 5, 2021 · If we’re going to get such data only once and avoid duplication events after configuration changes, we can use the SingleLiveEvent<T> instead of the MutableLiveData<T>. I could not find documentation for same. Jan 21, 2019 · MutableLiveData is a subclass of LiveData that provides a setter method for the underlying value; we cannot set the value on a LiveData instance directly. Nov 28, 2019 · I have a LiveData variable that I want to assign a value to after receiving a response from a HTTP request. . We will look at the difference between these two methods. Feb 11, 2019 · I observed that MutableLiveData triggers onChanged of an observer even if the same object instance is provided to its setValue method. To actually change that stored value, you need a MutableLiveData - this has the setValue (and similar) functions that allow you to Dec 28, 2021 · When changing the data on the Main thread, use the MutableLiveData class's setValue method, and when changing the LiveData on the background thread, use the MutableLiveData class's postValue method GeekTip: So, in essence, it is requesting that the main thread set the new updated value and then notify the observers. I tried to reverse the 2 fragments but still the same problem. Observers: Observers are interfaces (like Observer or LifecycleObserver) that define how components react to data changes. Understanding the lifecycle of LiveData and its observers is key to solving this issue. so MutableLiveData is used to record the changed value and LiveData is used to notify the UI about the change Jul 23, 2025 · Note: Here we are using MutableLiveData right. If you give SharedFlow a replay value of 0, new Activities and Fragments that observe it will not get the previous value, only newly posted values. getValue() is null I have to call api for data and insert in into the database which will eventually call the onChange() method from where I will get the data. Here is class MutableLiveData of Android. Apr 21, 2020 · Livedata: Setvalue vs Postvalue In an app processes run both on main as well as background threads. Jun 3, 2023 · In the realm of Android development, LiveData has emerged as a valuable tool for building reactive and data-driven applications. I assign this value inside the launch {} scope. Why We Need LiveData and MutableLiveData: Jul 12, 2018 · There are two ways that make change value of MutableLiveData. postValue (String. Some Android developers recommend switching from LiveData to Flows anyway to better decouple data from views. myapplication D/TAG: androidx. Por lo general, MutableLiveData se usa en ViewModel y, luego, ViewModel solo expone objetos LiveData inmutables a los observadores. postValue(null) //Error Cannot set non-nullable LiveData value to null [NullSafeMutableLiveData] parameter String of _error is obviously nullable, am I doing something wrong? Dec 14, 2023 · With MutableLiveData, we use the . での変更を監視するオブザーバー メソッドを追加する方法 レイアウト ファイル内にバインディング式を記述する方法 作成するアプリの Aug 3, 2022 · We’ve already implemented MVVM using Data Binding and covered LiveData and Data Binding in separate tutorials. In other words, if you Sep 17, 2019 · Now when the activity gets destroyed and then created again, i still get the old value from repository unless i fetch the new one manually. Sep 24, 2024 · In the CounterViewModel, we have defined a count property of type MutableLiveData<Int> with an initial value of 0. score. Jun 8, 2020 · I need to change the value of MutableLiveData in my ViewModel, but I can't make it because the value is equal to null, I think need to establish an observer change it inside that, but I don't know Sep 8, 2021 · Type mismatch: inferred type is DecimalFormat but MutableLiveData<String> was expected appears within the when statement when setting the new value for sharedViewModel. Jun 16, 2020 · In fact, the function returns immediately the LiveData (with a null value as content) and then Room using a background thread executes the query and updates the LiveData. How can I get _receiverListItems value dependent on _sender value? android kotlin android-livedata observers mutablelivedata asked Nov 6, 2022 at 21:48 Khalida Discover the best practices for setting the value of `MutableLiveData Boolean ` in Kotlin and how to handle null cases effectively!---This video is based on Jun 14, 2022 · The code in the observer will only run when propertyItemLiveData pushes a new value, or if it already has a value when you first observe it. value = listOf() GlobalScope. However, when I load the 2nd page and I add the additional items to the list, the callback is not triggered. Sep 12, 2022 · In this post I want to cover on where/how to make API calls on a Jetpack compose screen. But what is difference between setValue() & postValue() in MutableLiveData. MutableLiveData allows you to directly modify the held value. switchMap which reacts on changes to Mar 13, 2018 · MutableLiveData<List<SearchResult>> When I do the initial load and set the variable to a new list, it triggers a callback on the binding adapter that loads the data into the recyclerview. Jul 12, 2018 · MutableLiveData has been updated and now it has a constructor that accepts an initial value :) From what I can see, the constructor is available starting from this version: implementation 'androidx. How to get an element from MutableLiveData to get its fields . May 17, 2022 · Android Kotlin Live Data & Mutable Live Data Example Live data or Mutable Live Data is an observable data holder class. example. Then, whenever that value changes, every registered observer will be called again with the new value. But from the docs: As soon as an app component is in the STARTED state, it receives the most recent value from the LiveData objects it’s observing. Therefore, if you want to update the stored data, you must use MutableLiveData instead of LiveData. value property. But lets dive in, to understand how these two methods differ. But Because of that null value if and getting data from both database and api. Android’s LiveData can be observed and changed anywhere without a coroutine with its observeForever() . For example when I do Feb 25, 2019 · MutableLiveData sets value but getValue () returns null? Asked 6 years, 9 months ago Modified 6 years, 9 months ago Viewed 9k times Oct 14, 2022 · This topic is related to this one. If you called this method multiple times before a main thread executed a posted task, only the last value would be dispatched. With setValue, you can set the new value and after that, it calls all the active observers with new Dec 15, 2018 · if you want to update your favorite status on your view than you can have favorite variable as MutableLiveData and bind it with your view. Nov 15, 2018 · object AddressList: MutableLiveData<List<Address>>() fun getAddressesLiveData(): LiveData<List<Address>> { AddressList. Hence you’ll use MutableLiveData to update the value inside LiveData with the help of the following two options: setValue: sets the value instantly. We also have two methods, onIncrement and onDecrement, to update the count. To get rid of reading from livedata I would have to store items in ordinary variable, so I would have two variables with the same data: one List<Item>, and the other one MutableLiveData<List<Item>> and update both of them in above function to keep them in sync, but is it worth it? Aug 25, 2024 · MutableLiveData: It is mutable, meaning its value can be changed. value). You shouldn't do this, but just to prove the point, if you add an observer before accessing the value it should work: Oct 9, 2024 · _count. The fundamental problem is the data problem. We’ll see how LiveData makes it easy to update the UI from the ViewModel. value = true foo. view will get updated for every new value for favorite variable. Prerequisite. Dec 3, 2018 · The setter of the property has no relevance for your MutableLiveData, as its mutability within the object itself. None of the following work Jul 28, 2024 · Methods of MutableLiveData setValue (T value) : Sets a new value for the MutableLiveData and should be used on the main thread. Jul 23, 2018 · By UI controllers mean our ViewModel and LiveData class. We can see why by looking at the Java: But there’s a more pernicious problem. value = "value" and expose only an Nov 6, 2022 · When a new value is posted by doing _sender. Transformation class to monitor for individual fields. value (in your case sharedViewModel. value = _count. Jun 28, 2021 · For a framework solution, I suggest SharedFlow. setValue (java. setValue(): set the value and dispatch the value to all the active observers, must be called from main thread. It provides a streamlined way to observe and react to data changes Apr 5, 2020 · You can use emptyList<Int>() or listOf<Int>() to create the MutableLiveData avoiding the unchecked cast: val test: LiveData<List<Int>> get() = _test private var _test = MutableLiveData(emptyList<Int>()) If your code was just a sample of your real use case, remember you can always use . The value gets updated quite alright but the UI only shows the May 14, 2024 · In MutableLiveData we can observe and set the values using postValue () and setValue () methods. Internally MutableLiveData extends LiveData class and exposes the two methods publically which is setValue and getValue. value = mutableListOf<Student>() } Observer is only being called when the application starts i. lang. But if data changes in ViewModel it won't reflect its View. MutableLiveData: Exploring Value Setting Methods in Kotlin Hey friends hows going on?, few days ago I appreard for one Interview and there I was asked difference, use case and Aug 3, 2022 · I am using MutableLiveData to pass the value from my background task to my main activity for display on the screen. How can I get _receiverListItems value dependent on _sender value? android kotlin android-livedata observers mutablelivedata asked Nov 6, 2022 at 21:48 Khalida Aug 17, 2024 · Courtesy of Imgflip Problem #1: Null safety LiveData is not null safe! As you can see, you always have to check for null when you get the value. arch. Jun 16, 2019 · It is because of using MutableLiveData. toList() on your MutableList. In this blog, we will learn about LiveData and the methods that are used to update the value of the LiveData i. Dec 30, 2017 · For information, a simple MutableLiveData <String> (set & get) works in the first fragment of my ViewPager. This similarity in syntax simplifies the migration process, as it requires minimal changes in the way values are updated. With setValue, you can set the new value and after that, it calls all the active observers with new Jul 12, 2018 · There are two ways that make change value of MutableLiveData. Jun 14, 2022 · As soon as an app component is in the STARTED state, it receives the most recent value from the LiveData objects it’s observing. Even though we’ve declared this MutableLiveData<String> as being non-nullable, we’re able to set its value to null! Sep 10, 2021 · I want to add an item to a List of MutableLiveData in ViewModel. I need to add an element to the first position of the array and tried with &quot Jun 8, 2020 · I have a function 'A' in a ViewModel that retrieves data from firebase and I assign the value to a MutableLiveData<Int> (all of this is wrapped in onSuccessListener)and return it. Nov 24, 2020 · How can I fill the RecycleView from MutableLiveData<State<List>>. Feb 10, 2025 · The MutableLiveData class exposes the setValue(T) and postValue(T) methods publicly and you must use these if you need to edit the value stored in a LiveData object. This only occurs if the LiveData object to be observed has been set. Feb 20, 2021 · I am trying to get an object from a MutableLiveData<Resource<ObjectIWant>> to a var hereIwantTheObject : ObjectIWant in my HomeFragment, apparently use the Resource class is the recomme Dec 3, 2018 · The setter of the property has no relevance for your MutableLiveData, as its mutability within the object itself. lifecycle. Jun 14, 2022 · As soon as an app component is in the STARTED state, it receives the most recent value from the LiveData objects it’s observing. setValue () method and postValue () method. Mar 25, 2019 · Plain primitives and Strings are not observable by default so if you use them in your Data Binding layouts, their values will be used when the binding is created but subsequent changes to them Dec 20, 2021 · To get it working, I’ll have to modify the SafeMutableLiveData to also have a copy of MutableLiveData that get saved and restored as shown below. However, LiveData has no publicly available methods to update the stored data. List is read-only because it was initialized with listOf(). Today, we’ll use LiveData with Data Binding in our MVVM Android Application. Use postValue () only when updating LiveData from a background thread. Nov 29, 2023 · Android LiveData’s setValue () vs postValue () While working with LiveData we can use two different methods to update its value. Apr 3, 2024 · However, you typically use its subclass - MutableLiveData. None of the following work Jun 8, 2019 · Consider the following ways to expose MutableLiveData: Method A class ThisViewModel : ViewModel() { private val _someData = MutableLiveData(true) val someData: LiveData&lt;Boolean&gt; Aug 3, 2022 · We’ve already implemented MVVM using Data Binding and covered LiveData and Data Binding in separate tutorials. Jul 23, 2025 · Actually, If we want our views to directly communicate with ViewModel (Data source), we can do that simply without using LiveData. postValue in TypeConverter and not existing observer on the property. Sep 2, 2021 · java android viewmodel android-livedata edited Sep 2, 2021 at 15:30 Karunesh Palekar 2,34511323 asked Sep 2, 2021 at 9:02 Monsieur DanKar 12 You are calling liveData. val selectedLiveData by lazy { MutableLiveData<List<Core>>() } I don't want to trigger the observers so I am not assigning the value as I just want to remove a single element from the liveData list and only trigger when adding. Oct 12, 2023 · Specifically, you can use setValue(T value) for main thread operations or postValue(T value) for background thread operations. Jun 8, 2017 · I want to use livedataif sections. I also don't understand what the purpose of cachedResendOtpResponse is. minus(1) } } Types of LiveData: MutableLiveData: A subclass of LiveData that allows modification of the data it holds. It is very bad for a state to be uninitialized. e. You can use androidx. I will be glad to see an example of the code on kotlin to solve my problem Thanks! Updated: My problem is that I can't bind the object. The MutableLiveData class adds two public methods that allow you to set the value of a LiveData object: setValue アプリで LiveData と MutableLiveData を使用する方法 ViewModel に保存されているデータを LiveData でカプセル化する方法 LiveData. Jul 5, 2023 · LiveData vs. Aug 24, 2020 · Synchronous vs Asynchronous Update LiveData doesn’t have public methods to update its value. Nov 22, 2018 · The MutableLiveData class exposes the setValue (T) and postValue (T) methods publicly and you must use these if you need to edit the value stored in a LiveData object. If I were doing it the first way, I’d name the function “update” instead of “get” since the function isn’t directly returning something, but rather is updating the LiveData with the most put to date Feb 13, 2025 · Always expose LiveData instead of MutableLiveData to prevent modification from UI components. Jan 10, 2018 · BTW it is important to me to keep this data in the separate object and not use primary values like Strings in my ViewModel. At that point you get your value. What is MutableLiveData: MutableLiveData is also a LiveData. value?. Edit: they finally did it! MediatorLiveData has a constructor that accepts MutableLiveData is a class in Android's Lifecycle library that represents a data holder with observable lifecycle-aware properties. But that’s the way it works. It might not matter in the app you’re developing in this project, but in a production app, you want control over the data in the ViewModel objects. Feb 21, 2018 · Attempt to invoke virtual method 'void android. However, if I replace the list with a new list containing both the old and new items, the callback Aug 5, 2021 · I tried three ways to no avail, such as: LiveData, MutableLiveData, mutableStateListOf, MutableStateFlow According to the test, I found that the value has changed, but the interface is not updated. So, we didn’t use any MediatorLiveData here as our use case is covered by the MutableLiveData. val Sep 11, 2020 · _displayCheckBox is a MutableLiveData<Boolean>, I hope to set it as adverse. value = false // and that foo. This can lead to potential data inconsistencies if not used carefully. Dec 16, 2020 · _error. They implement methods like onChanged(T value) to handle updates. postValue(T value) method from background thread. Usually MutableLiveData is used in the ViewModel and then the ViewModel only exposes immutable LiveData objects to the observers. //Fragment#onCreateView - scenario1 val newValue = "newValue" Nov 16, 2019 · When you enter two values and then press the plus button then result will be visible. private val _exampleData = MutableLiveData<String>() val exampleData: LiveData<String> get() = _exampleData You can change the value privately with _exampleData. In an essence the traditional UI system and and compose differs on where do we invoke the remote/async API vs how the data delivered to us. MutableLiveData@12c1fa8 I am trying to log out the value but it simply doesn't happen, same occurs when I display it as a toast in my Main Activity Sep 9, 2017 · Although what I did was to subclass LiveData and have a private inner MutableLiveData so there is no way that any outside classes can change the value of my LiveData to null. However, developers often encounter a scenario where MutableLiveData sets a value successfully, yet retrieving it using getValue () returns null. Now, forget about MutableLiveData in your case. value!! can't work well, how can I fix it? Code A p Oct 22, 2018 · This is all nice, but be aware! val foo = MutableLiveData<Boolean>() // this foo. This blog focuses on understanding how to 49 You can use MutableLiveData<T>. value = !_displayCheckBox. but the question is why? because there is already LiveData is available, MutableLiveData extends LiveData class and two functions setValue () and postValue () are publicly available for use. lifecyle. I tried inserting the new data but it is not reflecting as expected. We use background thread for processes like data fetch or running some service for which we do Dec 27, 2019 · The type is said to be String, but the value property access (which is getValue() in Java) still returns a nullable value. Apr 27, 2023 · A LiveData stores a single value, and pushes updates to observers. resendOTP does. @Test fun mutableStateFlow() { val bl = MutableStateFlow(3) val bp = bl. Now I want to have the returned data stored in a ViewModel, but the problem is that in order to get said value, I need to observe the LiveData object returned from my data fetching class. Queries Oct 18, 2017 · Whereas, in MutableLiveData - Android Developer Documentation, you can see that, MutableLiveData extends LiveData internally and also the two magic methods of LiveData is publicly available in this and they are setValue() & postValue(). But It seems that _displayCheckBox. When the LiveData value changes, all these fragments need to be notified and update their UI. I have tried another option which is to use runBlocking {} scope instead of launch {} scope and my test case Jun 22, 2022 · How to create Kotlin List, how to add, update, replace, remove items in mutable List, iterate over List, combine Lists, reverse, find items in Kotlin List . Used within the ViewModel to update data. 1. Differ Jan 8, 2024 · But the first way with MutableLiveData is likely more appropriate because it will preserve what was fetched if the activity is destroyed and recreated, such as after a screen rotation. postValue(false) Both this and that sets the live data value to true and then to false, so you probably expect, if observing foo, you’ll get your code to run twice, once with true and once with false. Looks like when the Observer is set to a ViewModel it takes some time to get initialized and in the meantime, if we are trying to setValue to a LiveData, it throws the NullPointerException as the ViewModel is not initialized yet. When something observe s it, that Observer will be called if the LiveData currently has a value. khy hdt rojvntoz aqvci lmeg ptthprg fyhevrj ybuf bqone newtyf qghj fwef qyv kbyzuq ril