rx.quasar

Class BlockingObservable<T>

java.lang.Object

rx.quasar.BlockingObservable<T>

Type Parameters:

T -

public class BlockingObservable<T>
extends java.lang.Object

An extension of Observable that provides blocking operators, compatible with both threads and fibers.

You construct a BlockingObservable from an Observable with from(Observable).

The documentation for this interface makes use of a form of marble diagram that has been modified to illustrate blocking operators. The following legend explains these marble diagrams:

For more information see the Blocking Observable Operators page at the RxJava Wiki.

Method Summary

Methods

Modifier and Type	Method and Description
T	first() Returns the first item emitted by a specified Observable, or IllegalArgumentException if source contains no elements.
T	first(rx.functions.Func1<? super T,java.lang.Boolean> predicate) Returns the first item emitted by a specified Observable that matches a predicate, or IllegalArgumentException if no such item is emitted.
T	firstOrDefault(T defaultValue) Returns the first item emitted by a specified Observable, or a default value if no items are emitted.
T	firstOrDefault(T defaultValue, rx.functions.Func1<? super T,java.lang.Boolean> predicate) Returns the first item emitted by a specified Observable that matches a predicate, or a default value if no such items are emitted.
void	forEach(rx.functions.Action1<? super T> onNext) Invoke a method on each item emitted by the Observable; block until the Observable completes.
static <T> BlockingObservable<T>	from(rx.Observable<? extends T> o) Convert an Observable into a BlockingObservable.
T	last() Returns the last item emitted by a specified Observable, or throws IllegalArgumentException if it emits no items.
T	last(rx.functions.Func1<? super T,java.lang.Boolean> predicate) Returns the last item emitted by a specified Observable that matches a predicate, or throws IllegalArgumentException if it emits no such items.
T	lastOrDefault(T defaultValue) Returns the last item emitted by a specified Observable, or a default value if no items are emitted.
T	lastOrDefault(T defaultValue, rx.functions.Func1<? super T,java.lang.Boolean> predicate) Returns the last item emitted by a specified Observable that matches a predicate, or a default value if no such items are emitted.
co.paralleluniverse.strands.channels.ReceivePort<T>	latest() Returns the latest item emitted by the underlying Observable, waiting if necessary for one to become available.
co.paralleluniverse.strands.channels.ReceivePort<T>	mostRecent(T initialValue) Returns an Iterable that always returns the item most recently emitted by an Observable.
co.paralleluniverse.strands.channels.ReceivePort<T>	next() Returns an Iterable that blocks until the Observable emits another item, then returns that item.
T	single() If the Observable completes after emitting a single item, return that item, otherwise throw an IllegalArgumentException.
T	single(rx.functions.Func1<? super T,java.lang.Boolean> predicate) If the Observable completes after emitting a single item that matches a given predicate, return that item, otherwise throw an IllegalArgumentException.
T	singleOrDefault(T defaultValue) If the Observable completes after emitting a single item, return that item; if it emits more than one item, throw an IllegalArgumentException; if it emits no items, return a default value.
T	singleOrDefault(T defaultValue, rx.functions.Func1<? super T,java.lang.Boolean> predicate) If the Observable completes after emitting a single item that matches a predicate, return that item; if it emits more than one such item, throw an IllegalArgumentException; if it emits no items, return a default value.
co.paralleluniverse.strands.channels.ReceivePort<T>	toChannel() Returns an ReceivePort that receives all items emitted by a specified Observable.
java.util.concurrent.Future<T>	toFuture() Returns a Future representing the single value emitted by an Observable.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

from

public static <T> BlockingObservable<T> from(rx.Observable<? extends T> o)

Convert an Observable into a BlockingObservable.

forEach

@Suspendable
public void forEach(rx.functions.Action1<? super T> onNext)

Invoke a method on each item emitted by the Observable; block until the Observable completes.

NOTE: This will block even if the Observable is asynchronous.

This is similar to Observable.subscribe(Subscriber), but it blocks. Because it blocks it does not need the Observer.onCompleted() or Observer.onError(Throwable) methods.

Parameters:

onNext - the Action1 to invoke for every item emitted by the Observable

Throws:

java.lang.RuntimeException - if an error occurs

See Also:

RxJava Wiki: forEach()

toChannel

public co.paralleluniverse.strands.channels.ReceivePort<T> toChannel()

Returns an ReceivePort that receives all items emitted by a specified Observable.

Returns:

an ReceivePort that receives all items emitted by a specified Observable.

first

@Suspendable
public T first()

Returns the first item emitted by a specified Observable, or IllegalArgumentException if source contains no elements.

Returns:

the first item emitted by the source Observable

Throws:

java.lang.IllegalArgumentException - if source contains no elements

See Also:

RxJava Wiki: first(), MSDN: Observable.First

first

@Suspendable
public T first(rx.functions.Func1<? super T,java.lang.Boolean> predicate)

Returns the first item emitted by a specified Observable that matches a predicate, or IllegalArgumentException if no such item is emitted.

Parameters:

predicate - a predicate function to evaluate items emitted by the Observable

Returns:

the first item emitted by the Observable that matches the predicate

Throws:

java.lang.IllegalArgumentException - if no such items are emitted

See Also:

RxJava Wiki: first(), MSDN: Observable.First

firstOrDefault

@Suspendable
public T firstOrDefault(T defaultValue)

Returns the first item emitted by a specified Observable, or a default value if no items are emitted.

Parameters:

defaultValue - a default value to return if the Observable emits no items

Returns:

the first item emitted by the Observable, or the default value if no items are emitted

See Also:

RxJava Wiki: firstOrDefault(), MSDN: Observable.FirstOrDefault

firstOrDefault

@Suspendable
public T firstOrDefault(T defaultValue,
                           rx.functions.Func1<? super T,java.lang.Boolean> predicate)

Returns the first item emitted by a specified Observable that matches a predicate, or a default value if no such items are emitted.

Parameters:

defaultValue - a default value to return if the Observable emits no matching items

predicate - a predicate function to evaluate items emitted by the Observable

Returns:

the first item emitted by the Observable that matches the predicate, or the default value if no matching items are emitted

See Also:

RxJava Wiki: firstOrDefault(), MSDN: Observable.FirstOrDefault

last

@Suspendable
public T last()

Returns the last item emitted by a specified Observable, or throws IllegalArgumentException if it emits no items.

Returns:

the last item emitted by the source Observable

Throws:

java.lang.IllegalArgumentException - if source contains no elements

See Also:

RxJava Wiki: last(), MSDN: Observable.Last

last

@Suspendable
public T last(rx.functions.Func1<? super T,java.lang.Boolean> predicate)

Returns the last item emitted by a specified Observable that matches a predicate, or throws IllegalArgumentException if it emits no such items.

Parameters:

predicate - a predicate function to evaluate items emitted by the Observable

Returns:

the last item emitted by the Observable that matches the predicate

Throws:

java.lang.IllegalArgumentException - if no such items are emitted

See Also:

RxJava Wiki: last(), MSDN: Observable.Last

lastOrDefault

@Suspendable
public T lastOrDefault(T defaultValue)

Returns the last item emitted by a specified Observable, or a default value if no items are emitted.

Parameters:

defaultValue - a default value to return if the Observable emits no items

Returns:

the last item emitted by the Observable, or the default value if no items are emitted

See Also:

RxJava Wiki: lastOrDefault(), MSDN: Observable.LastOrDefault

lastOrDefault

@Suspendable
public T lastOrDefault(T defaultValue,
                          rx.functions.Func1<? super T,java.lang.Boolean> predicate)

Returns the last item emitted by a specified Observable that matches a predicate, or a default value if no such items are emitted.

Parameters:

defaultValue - a default value to return if the Observable emits no matching items

predicate - a predicate function to evaluate items emitted by the Observable

Returns:

the last item emitted by the Observable that matches the predicate, or the default value if no matching items are emitted

See Also:

RxJava Wiki: lastOrDefault(), MSDN: Observable.LastOrDefault

mostRecent

public co.paralleluniverse.strands.channels.ReceivePort<T> mostRecent(T initialValue)

Returns an Iterable that always returns the item most recently emitted by an Observable.

Parameters:

initialValue - the initial value that will be yielded by the Iterable sequence if the Observable has not yet emitted an item

Returns:

an Iterable that on each iteration returns the item that the Observable has most recently emitted

See Also:

RxJava wiki: mostRecent(), MSDN: Observable.MostRecent

next

public co.paralleluniverse.strands.channels.ReceivePort<T> next()

Returns an Iterable that blocks until the Observable emits another item, then returns that item.

Returns:

an Iterable that blocks upon each iteration until the Observable emits a new item, whereupon the Iterable returns that item

See Also:

RxJava Wiki: next(), MSDN: Observable.Next

latest

public co.paralleluniverse.strands.channels.ReceivePort<T> latest()

Returns the latest item emitted by the underlying Observable, waiting if necessary for one to become available.

If the underlying Observable produces items faster than the Iterator.next() takes them, onNext events might be skipped, but onError or onCompleted events are not.

Note also that an onNext() directly followed by onCompleted() might hide the onNext() event.

Returns:

the receive port

See Also:

RxJava wiki: latest(), MSDN: Observable.Latest

single

@Suspendable
public T single()

If the Observable completes after emitting a single item, return that item, otherwise throw an IllegalArgumentException.

Returns:

the single item emitted by the Observable

See Also:

RxJava Wiki: single(), MSDN: Observable.Single

single

@Suspendable
public T single(rx.functions.Func1<? super T,java.lang.Boolean> predicate)

If the Observable completes after emitting a single item that matches a given predicate, return that item, otherwise throw an IllegalArgumentException.

Parameters:

predicate - a predicate function to evaluate items emitted by the Observable

Returns:

the single item emitted by the source Observable that matches the predicate

See Also:

RxJava Wiki: single(), MSDN: Observable.Single

singleOrDefault

@Suspendable
public T singleOrDefault(T defaultValue)

If the Observable completes after emitting a single item, return that item; if it emits more than one item, throw an IllegalArgumentException; if it emits no items, return a default value.

Parameters:

defaultValue - a default value to return if the Observable emits no items

Returns:

the single item emitted by the Observable, or the default value if no items are emitted

See Also:

RxJava Wiki: singleOrDefault(), MSDN: Observable.SingleOrDefault

singleOrDefault

@Suspendable
public T singleOrDefault(T defaultValue,
                            rx.functions.Func1<? super T,java.lang.Boolean> predicate)

If the Observable completes after emitting a single item that matches a predicate, return that item; if it emits more than one such item, throw an IllegalArgumentException; if it emits no items, return a default value.

Parameters:

defaultValue - a default value to return if the Observable emits no matching items

predicate - a predicate function to evaluate items emitted by the Observable

Returns:

the single item emitted by the Observable that matches the predicate, or the default value if no such items are emitted

See Also:

RxJava Wiki: singleOrDefault(), MSDN: Observable.SingleOrDefault

toFuture

public java.util.concurrent.Future<T> toFuture()

Returns a Future representing the single value emitted by an Observable.

toFuture() throws an exception if the Observable emits more than one item. If the Observable may emit more than item, use toList().toFuture().

Returns:

a Future that expects a single item to be emitted by the source Observable

See Also:

RxJava Wiki: toFuture()