Last year we announced our investment in making Firebase libraries more Kotlin-friendly with Firebase Kotlin extension (KTX) libraries. Since then we have seen increasing interest for Kotlin within the Firebase community. In this blog post, we’ll go over how developing with Kotlin can lead to fewer crashes; and how you can monitor your app’s stability with Firebase Crashlytics once your app has been released.
Users expect to have a seamless experience every time they use your app. Crashes can cause churn and poor reviews, and quality issues are one of the main causes of early app deletion. Android apps built with Kotlin have 20% fewer crashes, which is one of the reasons that over 70% of the Top 1000 apps on the Play store have adopted Kotlin. Using Kotlin allows you to reduce the chances of getting null pointer exceptions, which are the #1 type of crashes on Google Play.
Furthermore Kotlin extension libraries let you write cleaner code by reducing boilerplate and making it easier to take advantage of advanced Kotlin language features even when using libraries originally written in Java.
In addition to our Firebase KTX libraries, you can also use the coroutines Kotlin extension libraries by Jetbrains to write safer async code with Kotlin and Firebase:
dependencies { // Coroutines implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.3.9' // Coroutines extensions for the Tasks API implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-play-services:1.3.9' // Firestore Kotlin extensions implementation 'com.google.firebase:firebase-firestore-ktx:22.0.2' }
Consider this code to fetch a document from Firestore. This code uses the Firebase Android SDK and the Play services Tasks library, both of which are Java libraries:
fun getUser() { val query = FirebaseFirestore.getInstance() .collection("users").document("user123") // query.get() returns a Task, we attach a callback to get the result query.get().addOnSuccessListener { snap -> val user = snap.toObject(User::class.java) } }
By using the Kotlin extension libraries above we can make this code simpler, safer, and easier to read:
suspend fun getUser() { // Firebase.firestore is a convenient syntax from the firestore-ktx library val query = Firebase.firestore .collection("users").document("user123") // The kotlinx-coroutines-play-services library allows us to "await" the // result of a Task and avoid callbacks, which simplifies our control flow val snap = query.get().await() // The .toObject<T> function from the firestore-ktx library uses Kotlin's support // for advanced generics to avoid the need to pass a Class object val user = snap.toObject<User>() }
Example provided by Firebase GDE Rosario Pereira Fernandes
Once you’ve developed and released your app, Firebase Crashlytics helps you improve and monitor your app stability. With Crashlytics you can track, prioritize and fix stability issues that erode app quality, in real-time. For instance, custom logs and keys in Crashlytics provides you with information on the specific state of your app leading up to a crash and gives context on why a crash occurred. With this level of in-depth insight, you can uncover the root causes of crashes more quickly before they affect a large number of your users.
For further analysis of your Crashlytics data and to segment your user data, you can also export all your crash data to BigQuery in real-time. For example, you can determine emerging crashes in new code, or see the top crash issues for the day to help you prioritize and fix them faster. You can also use our Data Studio template to easily visualize this data with custom dashboards. Data Studio dashboards are easy to collaborate on and share so your team can work more efficiently; even your team members who aren't comfortable with SQL can easily work around BigQuery data sets.
These are just a few examples of the ways you can improve your app stability with Firebase, Kotlin Extensions and Crashlytics. It’s easy to get started with Crashlytics and Firebase Kotlin Extension libraries, and as always if you need help please feel free to reach out to us through our Community Slack.
Happy developing!
We know that Kotlin is the future of Android and that Kotlin developers want clean, idiomatic APIs when they use Firebase in their apps. For the past year, we've been releasing Firebase Kotlin extension (KTX) libraries alongside our Android Java SDKs to give Kotlin developers the best of both worlds.
Today, we're happy to announce that these KTX libraries are out of Beta and recommended for all Firebase developers using Kotlin in their Android apps!
So what does this mean for you?
To get started with our KTX libraries, look for the -ktx suffix in the "Kotlin+KTX" section of our available Android libraries. As an example, let's see what it looks like to set up Remote Config with and without the KTX library.
-ktx
app/build.gradle (before)
implementation 'com.google.firebase:firebase-config:19.1.2'
MainActivity.kt (before)
val remoteConfig = FirebaseRemoteConfig.getInstance() val configSettings = FirebaseRemoteConfigSettings.Builder() .setMinimumFetchIntervalInSeconds(3600) .setFetchTimeoutInSeconds(60) .build() remoteConfig.setConfigSettingsAsync(configSettings)
app/build.gradle (after)
// The -ktx library has a dependency on the firebase-config library implementation 'com.google.firebase:firebase-config-ktx:19.1.2'
MainActivity.kt (after)
// New global "Firebase" class val remoteConfig = Firebase.remoteConfig // New settings builder syntax val configSettings = remoteConfigSettings { minimumFetchIntervalInSeconds = 3600 fetchTimeoutInSeconds = 60 } remoteConfig.setConfigSettingsAsync(configSettings)
And the KTX libraries that we have available today are just the beginning, as we're working hard to add coverage for all Firebase products and add new Kotlin-focused features in the near future!
We wouldn't have been able to release these KTX libraries without the help of all the Kotlin enthusiasts in the Firebase community. We'd like to give a special shout out to Rosário Pereira Fernandes who contributed so much excellent code and documentation to the KTX effort.
If you have feedback or want to contribute, you can find us on GitHub.
