LiveStream is a data holder class which can observe change of data in real-time and emit values too. Unlike other observables, LiveStream uses different approach. Here's emitter subscriber pattern. It's developed in Kotlin and fully compatible with Java.
LiveStream
is different than any other data observables. As compared to Android Architecture Component's LiveData
it's totally different. In LiveData
, you need to share the instance and then you need to add observer to listen for changes. It's useful in ViewModel
to share data.
LiveStream
is useful in background and UI data sharing. Here, you need to subscribe to data stream and just need to emit data values and subscribe data stream from anywhere in the application using multiple instances of LiveStream
.
For e.g. You have following classes in app-
- UI Class -
MainActivity
- Service Class -
BackgroundService
To share data in both classes, you will just need to add subscriber in UI class (MainActivity). In MainActivity, you'll subscribe to httpResponse
stream.
In BackgroundService
class, whenever you want to share data, you will just need to emit data on stream - httpResponse
.
Then, those who subscribed for httpResponse
data stream will be dispatched on value emission.
This library is fully compatible with Java. Here we've demonstrated using Kotlin.
Add below dependency in build.gradle
of your app module.
dependencies {
implementation 'dev.shreyaspatil:LiveStream-kt:0.2'
}
LiveStream
is a generic class. You can create instance as below.
private val liveStream = LiveStream<String>()
LiveStream
event will be dispatched when data is changed. See below code to add observer / subscriber.
Imagine, this code is in UI class of Android (e.g. MainActivity). Whenever value from background task (e.g. Service Class) is emitted, subscriber will listen live changes in data.
val observer = liveStream.subscribe("httpResponse") { response ->
showToast("This is HTTP response: $response")
}
LiveStream#subscribe()
method will return instance of StreamObserver
. This instance will be useful to unsubscribe from LiveStream
.
You can emit values in LiveData
from anywhere in the application. See below code.
To emit values from main thread, use LiveStream#set()
method.
val response = getResponse()
liveStream.set("httpResponse", response)
To emit values from other thread, use LiveStream#post()
method.
val response = getResponse()
liveStream.post("httpResponse", response)
To unsubscribe stream observer, use LiveStream#unsubscribe()
method. It has to pass instance of StreamObserver
which is obtained when you called subscribe()
method. See below code.
override fun onStop() {
super.onStop()
liveStream.unsubscribe(observer)
}
Sample code is available in /app
directory. Both Java & Kotlin code sample available.
If you want to contribute to this library, you're always welcome! See Contributing Guidelines.
If you need any help, you can connect with me.
Visit:- shreyaspatil.dev
MIT License
Copyright (c) 2020 Shreyas Patil
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