Decoupled android app communication with EventBus

Rashi Karanpuria
2 min readApr 12, 2017

While creating an app which had a lot of in app communication in use, I used broadcast receivers with bundles and parcelables. It quickly grew into a lot of code which was tightly coupled and hard to keep track of. Not to mention the time spent removing error cases due to activity and fragment lifecycle events.
So I decided to find a better way out for this, I came across a post about loose coupled in app communication using EventBus and I decided to give it try.

EventBus is an open-source library for Android using the publisher/subscriber pattern for loose coupling.

The event bus :
• simplifies the communication between app components.
• decouples event senders and receivers.
• helps avoid complex and error-prone dependencies and life cycle issues in activities & fragments.
• can be used with services. Awesome!
• makes your code super simple.
• is a tiny library which is way faster.
• has advanced features like delivery threads, subscriber priorities, etc.

Wait, there is more:
• annotation based api.
• Main and background thread delivery.
• event and subscriber inheritance.
• configurable to your requirements.
• sticky events.

And after you are all impressed and ready to move to the first tutorial you can put your hands on, hold on it just takes 3 steps.

1. Define events:

public class LocationEvent {    Location location;    public LocationEvent(Location location) {
this.location = location;
}
public Location getLocation() {
return location;
}
}

2. Prepare subscribers: Declare and annotate your subscribing method, optionally specify a thread mode:

@Subscribe
public void onLocationEvent(LocationEvent event) {
/* Do what you need to */
};

Register and unregister your subscriber. For example in an Activity (depends on component

Rashi Karanpuria

Software Engineer @ Google | Author of Kotlin Programming Cookbook | www.rashikaranpuria.com