/**
* 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.internal.operators;
import rx.*;
import rx.
Observable.
OnSubscribe;
import rx.exceptions.
Exceptions;
import rx.functions.
Func0;
import rx.observers.
Subscribers;
/**
* Do not create the Observable until an Observer subscribes; create a fresh Observable on each
* subscription.
* <p>
* <img width="640" src="https://github.com/ReactiveX/RxJava/wiki/images/rx-operators/defer.png" alt="">
* <p>
* Pass defer an Observable factory function (a function that generates Observables), and defer will
* return an Observable that will call this function to generate its Observable sequence afresh
* each time a new Observer subscribes.
* @param <T> the value type
*/
public final class
OnSubscribeDefer<T> implements
OnSubscribe<T> {
final
Func0<? extends
Observable<? extends T>>
observableFactory;
public
OnSubscribeDefer(
Func0<? extends
Observable<? extends T>>
observableFactory) {
this.
observableFactory =
observableFactory;
}
@
Override
public void
call(final
Subscriber<? super T>
s) {
Observable<? extends T>
o;
try {
o =
observableFactory.
call();
} catch (
Throwable t) {
Exceptions.
throwOrReport(
t,
s);
return;
}
o.
unsafeSubscribe(
Subscribers.
wrap(
s));
}
}