RxJava

Introduction

These are notes on RxJava which I have used with Android/Kotlin. To use with Android at the time you specify the following

dependencies {
...
    implementation 'io.reactivex.rxjava3:rxandroid:3.0.0'
    implementation 'io.reactivex.rxjava3:rxjava:3.0.13'
...
}

Observable Types

Singles

Single is an Observable which only emits one item or throws an error. Single emits only one value and applying some of the operator makes no sense. Like we don’t want to take value and collect it to a list.

interface SingleObserver<T> {
    void onSubscribe(Disposable d);
    void onSuccess(T value);
    void onError(Throwable error);
}

Completables

Because we are using java we have 3 types of observables,

• Completables
• Singles
• Maybes

This restricts the functions we need to implement.