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/*
* -\-\-
* Mobius
* --
* Copyright (c) 2017-2018 Spotify AB
* --
* 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 com.spotify.mobius.rx3;
import static com.spotify.mobius.internal_util.Preconditions.checkNotNull;
import com.spotify.mobius.ConnectionException;
import com.spotify.mobius.Mobius;
import com.spotify.mobius.MobiusLoop;
import com.spotify.mobius.Update;
import io.reactivex.rxjava3.core.Observable;
import io.reactivex.rxjava3.core.ObservableTransformer;
import io.reactivex.rxjava3.core.Scheduler;
import io.reactivex.rxjava3.functions.Action;
import io.reactivex.rxjava3.functions.Consumer;
import io.reactivex.rxjava3.functions.Function;
import io.reactivex.rxjava3.plugins.RxJavaPlugins;
import java.util.HashMap;
import java.util.Map;
import java.util.Set;
/** Factory methods for wrapping Mobius core classes in observable transformers. */
public final class RxMobius {
private RxMobius() {
// prevent instantiation
}
/**
* Create an observable transformer that starts from a given model.
*
* Every time the resulting observable is subscribed to, a new MobiusLoop will be started from
* the given model.
*
* @param loopFactory gets invoked for each subscription, to create a new MobiusLoop instance
* @param startModel the starting point for each new loop
* @param the model type
* @param the event type
* @param the effect type
* @return a transformer from event to model that you can connect to your UI
*/
public static ObservableTransformer loopFrom(
final MobiusLoop.Factory loopFactory, final M startModel) {
return new RxMobiusLoop<>(loopFactory, startModel, null);
}
/**
* Create an observable transformer that starts from a given model and given effects.
*
* Every time the resulting observable is subscribed to, a new MobiusLoop will be started from
* the given model and the given effects.
*
* @param loopFactory gets invoked for each subscription, to create a new MobiusLoop instance
* @param startModel the starting point for each new loop
* @param startEffects the starting effects for each new loop
* @param the model type
* @param the event type
* @param the effect type
* @return a transformer from event to model that you can connect to your UI
*/
public static ObservableTransformer loopFrom(
final MobiusLoop.Factory loopFactory,
final M startModel,
final Set startEffects) {
return new RxMobiusLoop<>(loopFactory, startModel, startEffects);
}
/**
* Create a {@link MobiusLoop.Builder} to help you configure a MobiusLoop before starting it.
*
* Once done configuring the loop you can start the loop using {@link
* MobiusLoop.Factory#startFrom(Object)}.
*
* @param update the {@link Update} function of the loop
* @param effectHandler the {@link ObservableTransformer} effect handler of the loop
* @param the model type
* @param the event type
* @param the effect type
* @return a {@link MobiusLoop.Builder} instance that you can further configure before starting
* the loop
*/
public static MobiusLoop.Builder loop(
Update update, ObservableTransformer effectHandler) {
return Mobius.loop(update, RxConnectables.fromTransformer(effectHandler));
}
/**
* Create an {@link RxMobius.SubtypeEffectHandlerBuilder} for handling effects based on their
* type.
*
* @param the effect type
* @param the event type
*/
public static RxMobius.SubtypeEffectHandlerBuilder subtypeEffectHandler() {
return new RxMobius.SubtypeEffectHandlerBuilder<>();
}
/**
* Builder for a type-routing effect handler.
*
* Register handlers for different subtypes of F using the add(...) methods, and call {@link
* #build()} to create an instance of the effect handler. You can then create a loop with the
* router as the effect handler using {@link #loop(Update, ObservableTransformer)}.
*
*
The handler will look at the type of each incoming effect object and try to find a
* registered handler for that particular subtype of F. If a handler is found, it will be given
* the effect object, otherwise an exception will be thrown.
*
*
All the classes that the effect router know about must have a common type F. Note that
* instances of the builder are mutable and not thread-safe.
*/
public static class SubtypeEffectHandlerBuilder {
private final Map, ObservableTransformer> effectPerformerMap = new HashMap<>();
private SubtypeEffectHandlerBuilder.OnErrorFunction<
ObservableTransformer, Consumer>
onErrorFunction = SubtypeEffectHandlerBuilder::defaultOnError;
private SubtypeEffectHandlerBuilder() {}
/**
* Add an {@link ObservableTransformer} for handling effects of a given type. The handler will
* receive all effect objects that extend the given class.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param effectHandler the effect handler for the given effect class
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addTransformer(
final Class effectClass, final ObservableTransformer effectHandler) {
checkNotNull(effectClass);
checkNotNull(effectHandler);
for (Class cls : effectPerformerMap.keySet()) {
if (cls.isAssignableFrom(effectClass) || effectClass.isAssignableFrom(cls)) {
throw new IllegalArgumentException(
"Effect classes may not be assignable to each other, collision found: "
+ effectClass.getSimpleName()
+ " <-> "
+ cls.getSimpleName());
}
}
effectPerformerMap.put(
effectClass,
(Observable effects) ->
effects
.ofType(effectClass)
.compose(effectHandler)
.doOnError(onErrorFunction.apply(effectHandler)));
return this;
}
/**
* Add a {@link Function} for handling effects of a given type. The function will be invoked
* once for every received effect object that extends the given class. The returned event will
* be forwarded to the Mobius loop.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param function the function that should be invoked for the effect
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addFunction(
final Class effectClass, final Function function) {
checkNotNull(effectClass);
checkNotNull(function);
return addTransformer(effectClass, Transformers.fromFunction(function));
}
/**
* Add a {@link Function} for handling effects of a given type. The function will be invoked
* once for every received effect object that extends the given class. The returned event will
* be forwarded to the Mobius loop.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param function the function that should be invoked for the effect
* @param scheduler the scheduler that should be used when invoking the function
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addFunction(
final Class effectClass, final Function function, Scheduler scheduler) {
checkNotNull(effectClass);
checkNotNull(function);
return addTransformer(effectClass, Transformers.fromFunction(function, scheduler));
}
/**
* Add an {@link Action} for handling effects of a given type. The action will be invoked once
* for every received effect object that extends the given class.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param action the action that should be invoked for the effect
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addAction(
final Class effectClass, final Action action) {
checkNotNull(effectClass);
checkNotNull(action);
return addTransformer(effectClass, Transformers.fromAction(action));
}
/**
* Add an {@link Action} for handling effects of a given type. The action will be invoked once
* for every received effect object that extends the given class.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param action the action that should be invoked for the effect
* @param scheduler the scheduler that should be used to invoke the action
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addAction(
final Class effectClass, final Action action, Scheduler scheduler) {
checkNotNull(effectClass);
checkNotNull(action);
return addTransformer(effectClass, Transformers.fromAction(action, scheduler));
}
/**
* Add an {@link Consumer} for handling effects of a given type. The consumer will be invoked
* once for every received effect object that extends the given class.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param consumer the consumer that should be invoked for the effect
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addConsumer(
final Class effectClass, final Consumer consumer) {
checkNotNull(effectClass);
checkNotNull(consumer);
return addTransformer(effectClass, Transformers.fromConsumer(consumer));
}
/**
* Add an {@link Consumer} for handling effects of a given type. The consumer will be invoked
* once for every received effect object that extends the given class.
*
* Adding handlers for two effect classes where one is a super-class of the other is
* considered a collision and is not allowed. Registering the same class twice is also
* considered a collision.
*
* @param effectClass the class to handle
* @param consumer the consumer that should be invoked for the effect
* @param scheduler the scheduler that should be used to invoke the consumer
* @param the effect class as a type parameter
* @return this builder
* @throws IllegalArgumentException if there is a handler collision
*/
public RxMobius.SubtypeEffectHandlerBuilder addConsumer(
final Class effectClass, final Consumer consumer, Scheduler scheduler) {
checkNotNull(effectClass);
checkNotNull(consumer);
return addTransformer(effectClass, Transformers.fromConsumer(consumer, scheduler));
}
/**
* Optionally set a shared error handler in case a handler throws an uncaught exception.
*
* The default is to use {@link RxJavaPlugins#onError(Throwable)}. Note that any exception
* thrown by a handler is a fatal error and this method doesn't enable safe error handling, only
* configurable crash reporting.
*
* @param function a function that gets told which sub-transformer failed and should return an
* appropriate handler for exceptions thrown.
*/
public RxMobius.SubtypeEffectHandlerBuilder withFatalErrorHandler(
final Function, Consumer> function) {
checkNotNull(function);
this.onErrorFunction =
new OnErrorFunction, Consumer>() {
@Override
public Consumer apply(ObservableTransformer effectHandler) {
try {
return function.apply(effectHandler);
} catch (Throwable e) {
throw new RuntimeException(
"FATAL: fatal error handler threw exception for effect handler: "
+ effectHandler,
e);
}
}
};
return this;
}
public ObservableTransformer build() {
return new MobiusEffectRouter<>(effectPerformerMap.keySet(), effectPerformerMap.values());
}
private static Consumer defaultOnError(
final ObservableTransformer effectHandler) {
return new Consumer() {
@Override
public void accept(Throwable throwable) throws Throwable {
RxJavaPlugins.onError(
new ConnectionException(
"in effect handler: " + effectHandler.getClass().toString(), throwable));
}
};
}
private interface OnErrorFunction extends Function {
// override in order to remove 'throws Exception'
@Override
R apply(T t);
}
}
}