[android-components](../../index.md) / [mozilla.components.feature.readerview](../index.md) / [ReaderViewFeature](index.md) / [registerMessageHandler](./register-message-handler.md)

# registerMessageHandler

`fun registerMessageHandler(session: `[`EngineSession`](../../mozilla.components.concept.engine/-engine-session/index.md)`, messageHandler: `[`MessageHandler`](../../mozilla.components.concept.engine.webextension/-message-handler/index.md)`): `[`Unit`](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin/-unit/index.html) [(source)](https://github.com/mozilla-mobile/android-components/blob/master/components/feature/readerview/src/main/java/mozilla/components/feature/readerview/ReaderViewFeature.kt#L306)