rx.operators.OperatorOnErrorResumeNextViaFunction Maven / Gradle / Ivy
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/**
* Copyright 2014 Netflix, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package rx.operators;
import rx.Observable;
import rx.Observable.Operator;
import rx.Subscriber;
import rx.functions.Func1;
/**
* Instruct an Observable to pass control to another Observable (the return value of a function)
* rather than invoking onError if it encounters an error.
*
* 
*
* By default, when an Observable encounters an error that prevents it from emitting the expected
* item to its Observer, the Observable invokes its Observer's onError method, and
* then quits without invoking any more of its Observer's methods. The onErrorResumeNext operation
* changes this behavior. If you pass a function that returns an Observable (resumeFunction) to
* onErrorResumeNext, if the source Observable encounters an error, instead of invoking its
* Observer's onError method, it will instead relinquish control to this new
* Observable, which will invoke the Observer's onNext method if it is able to do so.
* In such a case, because no Observable necessarily invokes onError, the Observer may
* never know that an error happened.
*
* You can use this to prevent errors from propagating or to supply fallback data should errors be
* encountered.
*/
public final class OperatorOnErrorResumeNextViaFunction implements Operator {
private final Func1> resumeFunction;
public OperatorOnErrorResumeNextViaFunction(Func1> f) {
this.resumeFunction = f;
}
@Override
public Subscriber call(final Subscriber child) {
return new Subscriber(child) {
@Override
public void onCompleted() {
child.onCompleted();
}
@Override
public void onError(Throwable e) {
try {
Observable resume = resumeFunction.call(e);
resume.subscribe(child);
} catch (Throwable e2) {
child.onError(e2);
}
}
@Override
public void onNext(T t) {
child.onNext(t);
}
};
}
}