How to use LocalBroadcastManager

Question

How to use locate LocalBroadcastManager as described in google docs and Service broadcast doc   I tried to google it  but there is no code available to start with   The documents say that I should use it if I want to do broadcast internally with in my app s process but I don t know where to look for this   Any help comment   Update  I know how to use Broadcasts but don t know how to get LocalBroadcastManager available in my project

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In Eclipse  eventually I had to add Compatibility Support Library by right-clicking on my project and selecting      Android Tools -  Add Support Library   Once it was added  then I was able to use LocalBroadcastManager class in my code

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I d rather like to answer comprehensively    LocalbroadcastManager included in android 3 0 and above so you have to use support library v4 for early releases  see instructions here Create a broadcast receiver   private BroadcastReceiver onNotice  new BroadcastReceiver           Override     public void onReceive Context context  Intent intent               intent can contain anydata         Log d  sohail   onReceive called            tv setText  Broadcast received                 Register your receiver in onResume of activity like   protected void onResume             super onResume             IntentFilter iff  new IntentFilter MyIntentService ACTION           LocalBroadcastManager getInstance this  registerReceiver onNotice  iff            MyIntentService ACTION is just a public static string defined in MyIntentService   unRegister receiver in onPause   protected void onPause       super onPause      LocalBroadcastManager getInstance this  unregisterReceiver onNotice      Now whenever a localbroadcast is sent from applications  activity or service  onReceive of onNotice will be called       Edit  You can read complete tutorial here LocalBroadcastManager  Intra application message passing

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By declaring one in your AndroidManifest xml file with the  tag  also called static     lt receiver android name   YourBrodcastReceiverClass   android exported  true  gt   lt intent-filter gt       lt  -- The actions you wish to listen to  below is an example -- gt       lt action android name  android intent action BOOT COMPLETED   gt   lt  intent-filter gt     You will notice that the broadcast receiver declared above has a property of exported    true     This attribute tells the receiver that it can receive broadcasts from outside the scope of the application  2  Or dynamically by registering an instance with registerReceiver  what is known as context registered   public abstract Intent registerReceiver  BroadcastReceiver receiver               IntentFilter filter    public void onReceive Context context  Intent intent      Implement your logic here     There are three ways to send broadcasts  The sendOrderedBroadcast method  makes sure to send broadcasts to only one receiver at a time  Each broadcast can in turn  pass along data to the one following it  or to stop the propagation of the broadcast to the receivers that follow  The sendBroadcast is similar to the method mentioned above  with one difference  All broadcast receivers receive the message and do not depend on one another  The LocalBroadcastManager sendBroadcast method only sends broadcasts to receivers defined inside your application and does not exceed the scope of your application

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An example of an Activity and a Service implementing a LocalBroadcastManager can be found in the developer docs  I personally found it very useful   EDIT  The link has since then been removed from the site  but the data is the following  https   github com carrot-garden android maven-android-plugin-samples blob master support4demos src com example android supportv4 content LocalServiceBroadcaster java

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localbroadcastmanager is deprecated  use implementations of the observable pattern instead   androidx localbroadcastmanager is being deprecated in version 1 1 0  Reason  LocalBroadcastManager is an application-wide event bus and embraces layer violations in your app  any component may listen to events from any other component      It inherits unnecessary use-case limitations of system BroadcastManager  developers have to use Intent even though objects live in only one process and never leave it  For this same reason  it doesn   t follow feature-wise BroadcastManager    These add up to a confusing developer experience   Replacement  You can replace usage of LocalBroadcastManager with other implementations of the observable pattern  Depending on your use case  suitable options may be LiveData or reactive streams   Advantage of LiveData  You can extend a LiveData object using the singleton pattern to wrap system services so that they can be shared in your app  The LiveData object connects to the system service once  and then any observer that needs the resource can just watch the LiveData object     public class MyFragment extends Fragment        Override     public void onActivityCreated Bundle savedInstanceState            super onActivityCreated savedInstanceState           LiveData lt BigDecimal gt  myPriceListener                myPriceListener observe this  price - gt                   Update the UI                        The observe   method passes the fragment  which is an instance of LifecycleOwner  as the first argument  Doing so denotes that this observer is bound to the Lifecycle object associated with the owner  meaning    If the Lifecycle object is not in an active state  then the observer isn t called even if the value changes  After the Lifecycle object is destroyed  the observer is automatically removed   The fact that LiveData objects are lifecycle-aware means that you can share them between multiple activities  fragments  and services

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On Receiving end       First register LocalBroadcast Receiver Then handle incoming intent data in onReceive      Override   protected void onCreate Bundle savedInstanceState          super onCreate savedInstanceState          LocalBroadcastManager lbm   LocalBroadcastManager getInstance this         lbm registerReceiver receiver  new IntentFilter  filter string            public BroadcastReceiver receiver   new BroadcastReceiver            Override       public void onReceive Context context  Intent intent              if  intent    null                  String str   intent getStringExtra  key                     get all your data from intent and do what you want                              On Sending End      Intent intent   new Intent  filter string       intent putExtra  key    My Data          put your all data using put extra      LocalBroadcastManager getInstance this  sendBroadcast intent

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enter code here if  createSuccses                           val userDataChange Intent BRODCAST USER DATA CHANGE                          LocalBroadcastManager getInstance this  sendBroadcast                              userDataChange                                                   enableSpinner false                          finish

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I am an iOS dev  so I made a solution similar to NotificationCenter  object NotificationCenter       var observers  MutableMap lt String  MutableList lt NotificationObserver gt  gt    mutableMapOf        fun addObserver observer  NotificationObserver  notificationName  NotificationName            var os   observers notificationName value          if  os    null                os   mutableListOf lt NotificationObserver gt                observers notificationName value    os                   os add observer             fun removeObserver observer  NotificationObserver  notificationName  NotificationName            val os   observers notificationName value          if  os    null                os remove observer                       fun removeObserver observer NotificationObserver            observers forEach   name  mutableList - gt              if  mutableList contains observer                     mutableList remove observer                                     fun postNotification notificationName  NotificationName  obj  Any             val os   observers notificationName value          if  os    null                os forEach  observer - gt                  observer onNotification notificationName obj                                   interface NotificationObserver       fun onNotification name  NotificationName obj Any      enum class NotificationName val value  String        onPlayerStatReceived  quot on player stat received quot               Some class that want to observe notification must conform to observer protocol  class MainActivity   AppCompatActivity    NotificationObserver       override fun onCreate savedInstanceState  Bundle                         NotificationCenter addObserver this NotificationName onPlayerStatReceived            override fun onDestroy                         super onDestroy           NotificationCenter removeObserver this                     override fun onNotification name  NotificationName  obj  Any             when  name                NotificationName onPlayerStatReceived - gt                    Log d tag   quot onPlayerStatReceived quot                             else - gt  Log e tag   quot Notification not handled quot                    Finally  post some notification to observers  NotificationCenter postNotification NotificationName onPlayerStatReceived null

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Kotlin version of using LocalBroadcastManager  Please check the below code for registering  sending and receiving the broadcast message  class MainActivity   AppCompatActivity         override fun onCreate savedInstanceState  Bundle             super onCreate savedInstanceState          setContentView R layout activity main              register broadcast manager         val localBroadcastManager   LocalBroadcastManager getInstance this          localBroadcastManager registerReceiver receiver  IntentFilter  quot your action quot                  broadcast receiver     var receiver  BroadcastReceiver   object   BroadcastReceiver             override fun onReceive context  Context   intent  Intent                 if  intent    null                    val str   intent getStringExtra  quot key quot                                                                  Send broadcast method             fun sendBroadcast             val intent   Intent  quot your action quot           intent putExtra  quot key quot    quot Your data quot           LocalBroadcastManager getInstance this  sendBroadcast intent              override fun onDestroy                Unregister broadcast         LocalBroadcastManager getInstance this  unregisterReceiver receiver          super onDestroy

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How to change your global broadcast to LocalBroadcast  1  Create Instance  LocalBroadcastManager localBroadcastManager   LocalBroadcastManager getInstance this     2  For registering BroadcastReceiver     Replace   registerReceiver new YourReceiver   new IntentFilter  YourAction          With   localBroadcastManager registerReceiver new YourReceiver   new IntentFilter  YourAction       3  For sending broadcast message     Replace   sendBroadcast intent        With   localBroadcastManager sendBroadcast intent     4  For unregistering  broadcast message     Replace   unregisterReceiver mybroadcast        With   localBroadcastManager unregisterReceiver mybroadcast

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When you ll play enough with LocalBroadcastReceiver I ll suggest you to give Green Robot s EventBus a try - you will definitely realize the difference and usefulness of it compared to LBR  Less code  customizable about receiver s thread  UI Bg   checking receivers availability  sticky events  events could be used as data delivery etc

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I ll answer this anyway  Just in case someone needs it    ReceiverActivity java  An activity that watches for notifications for the event named  custom-event-name     Override public void onCreate Bundle savedInstanceState                 Register to receive messages       We are registering an observer  mMessageReceiver  to receive Intents      with actions named  custom-event-name     LocalBroadcastManager getInstance this  registerReceiver mMessageReceiver        new IntentFilter  custom-event-name           Our handler for received Intents  This will be called whenever an Intent    with an action named  custom-event-name  is broadcasted  private BroadcastReceiver mMessageReceiver   new BroadcastReceiver        Override   public void onReceive Context context  Intent intent           Get extra data included in the Intent     String message   intent getStringExtra  message        Log d  receiver    Got message      message            Override protected void onDestroy          Unregister since the activity is about to be closed    LocalBroadcastManager getInstance this  unregisterReceiver mMessageReceiver     super onDestroy        SenderActivity java  The second activity that sends broadcasts notifications    Override public void onCreate Bundle savedInstanceState                 Every time a button is clicked  we want to broadcast a notification    findViewById R id button send  setOnClickListener new View OnClickListener          Override     public void onClick View v          sendMessage                      Send an Intent with an action named  custom-event-name   The Intent sent should     be received by the ReceiverActivity  private void sendMessage       Log d  sender    Broadcasting message      Intent intent   new Intent  custom-event-name         You can also include some extra data    intent putExtra  message    This is my message       LocalBroadcastManager getInstance this  sendBroadcast intent       With the code above  every time the button R id button send is clicked  an Intent is broadcasted and is received by mMessageReceiver in ReceiverActivity   The debug output should look like this   01-16 10 35 42 413  D sender 356   Broadcasting message 01-16 10 35 42 421  D receiver 356   Got message  This is my message

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we can also use interface for same as broadcastManger here i am sharing the testd code for broadcastManager but by interface   first make an interface like   public interface MyInterface        void GetName String name       2-this is the first class that need implementation   public class First implements MyInterface       MyInterface interfc          public static void main String   args          First f new First                Second s new Second          f initIterface s         f GetName  Paddy          private void initIterface MyInterface interfc       this interfc interfc        public void GetName String name        System out println  first   name       interfc GetName name             3-here is the the second class that implement the same interface whose method call automatically  public class Second implements MyInterface     public void GetName String name         System out println  Second  name            so by this approach we can use the interface functioning same as broadcastManager

[android] How to use LocalBroadcastManager?

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