com.spotify.mobius

Class Next<M,F>

java.lang.Object

com.spotify.mobius.Next<M,F>

public abstract class Next<M,F>
extends java.lang.Object

This class represents the result of calling an Update function.

Upon calling an Update function with an Event and Model, a Next object will be returned that contains the new Model (if there is one) and Effect objects that describe which side-effects should take place.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Next()

Method Summary

Modifier and Type	Method and Description
static <M,F> Next<M,F>	dispatch(java.util.Set<? extends F> effects) Create a Next that doesn't update the model but dispatches the supplied effects.
abstract java.util.Set<F>	effects() Get the effects of this Next.
boolean	hasEffects() Check if this Next contains effects.
boolean	hasModel() Check if this Next contains a model.
void	ifHasModel(Consumer<M> consumer) If the model is present, call the given consumer with it, otherwise do nothing.
protected abstract M	model() Get the model of this Next, if it has one.
M	modelOrElse(M fallbackModel) Try to get the model from this Next, with a fallback if there isn't one.
M	modelUnsafe() Get the model of this Next.
static <M,F> Next<M,F>	next(M model) Create a Next that updates the model but dispatches no effects.
static <M,F> Next<M,F>	next(M model, java.util.Set<? extends F> effects) Create a Next that updates the model and dispatches the supplied set of effects.
static <M,F> Next<M,F>	noChange() Create an empty Next that doesn't update the model or dispatch effects.

Methods inherited from class java.lang.Object

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

Constructor Detail

Next

protected Next()

Method Detail

model

@Nullable
protected abstract M model()

Get the model of this Next, if it has one. Might return null.

hasModel

public final boolean hasModel()

Check if this Next contains a model.

effects

@Nonnull
public abstract java.util.Set<F> effects()

Get the effects of this Next.

Will return an empty set if there are no effects.

hasEffects

public final boolean hasEffects()

Check if this Next contains effects.

modelOrElse

@Nonnull
public M modelOrElse(M fallbackModel)

Try to get the model from this Next, with a fallback if there isn't one.

Parameters:

fallbackModel - the default model to use if the Next doesn't have a model

modelUnsafe

@Nonnull
public M modelUnsafe()

Get the model of this Next. This version is unsafe - if this next doesn't have a model, calling this method will cause an exception to be thrown.

In almost all cases you should use modelOrElse(M) or ifHasModel(com.spotify.mobius.functions.Consumer<M>) instead.

Throws:

java.util.NoSuchElementException - if this Next has no model

ifHasModel

public void ifHasModel(Consumer<M> consumer)

If the model is present, call the given consumer with it, otherwise do nothing.

next

@Nonnull
public static <M,F> Next<M,F> next(M model,
                                            java.util.Set<? extends F> effects)

Create a Next that updates the model and dispatches the supplied set of effects.

next

@Nonnull
public static <M,F> Next<M,F> next(M model)

Create a Next that updates the model but dispatches no effects.

dispatch

@Nonnull
public static <M,F> Next<M,F> dispatch(java.util.Set<? extends F> effects)

Create a Next that doesn't update the model but dispatches the supplied effects.

noChange

@Nonnull
public static <M,F> Next<M,F> noChange()

Create an empty Next that doesn't update the model or dispatch effects.