I am trying to get my head around error handling in rxjava. I thought if i combine a stream of observables for instance in a zip() function that errors emitted by the observables within the zip would break the sequence and bubble up to the subscriber onError function. However the only error caught there are the ones emmitted in the BiFunction. Errors emitted up the chain causes the system to crash. when i add onErrorReturn to the observable and return a fallback value the system still crashes. So for me that does not work as I expected. What am I missing?
private fun getOneThing (): Single<String> {
println("getOneThing")
if (isOneBadCondition) {
throw Exception() //causes crash
} else {
return Single.just("a string thing")
}
}
private fun getAnotherThing(): Single<Boolean> {
println("getAnotherThing")
if (isAnotherBadCondition) {
throw Exception() //causes crash
} else {
return Single.just(true)
}
}
private fun createSomethingElse (): Int {
println("createAnother")
if (isBadCondition) {
throw Exception() //is handled onError
} else {
return 2
}
}
fun errorHandlingTest() {
Single.zip(
getOneThing(), //if I add onErrorReturn here it is not called after error
getAnotherThing(), //if I add onErrorReturn here it is not called after error
BiFunction<String, Boolean, Int> { t1, t2 ->
createSomethingElse()
}
).subscribeBy(
onSuccess ={ println(it) },
onError={ it.printStackTrace() }) //only error thrown by createSomethingElse() are caught here
}