Package com.vaadin.flow.internal.nodefeature

Class SignalBindingFeature

java.lang.Object

com.vaadin.flow.internal.nodefeature.NodeFeature

com.vaadin.flow.internal.nodefeature.ServerSideFeature

com.vaadin.flow.internal.nodefeature.SignalBindingFeature

All Implemented Interfaces:

Serializable

public class SignalBindingFeature
extends ServerSideFeature

Node feature for binding Signals to various properties of a node.

For internal use only. May be renamed or removed in a future release.

See Also:

• Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
static final String	CHILDREN
static final String	CLASSES
static final String	ENABLED
static final String	HTML_CONTENT
static final String	THEMES
static final String	VALUE

Constructor Summary

Constructors

Constructor	Description
SignalBindingFeature(StateNode node)	Creates a SignalBindingFeature for the given node.

Method Summary

Modifier and Type	Method	Description
void	clearBindings(String keyPrefix)	Clears all bindings with keys starting with the given prefix.
<T> Signal<T>	getSignal(String key)	Gets the signal bound to the given key.
<T> SerializableConsumer<T>	getWriteCallback(String key)	Gets the write callback for the given key.
boolean	hasBinding(String key)	Checks whether there is a binding for the given key.
void	removeBinding(String key)	Removes the binding for the given key.
void	setBinding(String key, Registration registration, Signal<?> signal)	Sets a binding for the given key.
void	setBinding(String key, Registration registration, Signal<?> signal, SerializableConsumer<?> writeCallback)	Sets a binding for the given key with a write callback.
<T> boolean	updateSignalByWriteCallback(String key, T oldValue, T newValue, SerializableBiPredicate<T,T> valueEquals, SerializableConsumer<T> revertCallback)	Updates the signal value by invoking the write callback for the given key.

Methods inherited from class com.vaadin.flow.internal.nodefeature.ServerSideFeature

collectChanges, forEachChild, generateChangesFromEmpty

Methods inherited from class com.vaadin.flow.internal.nodefeature.NodeFeature

allowsChanges, attachPotentialChild, detatchPotentialChild, getNode, onAttach, onDetach

Methods inherited from class java.lang.Object

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

Field Details

CLASSES

public static final String CLASSES

See Also:

• Constant Field Values

ENABLED

public static final String ENABLED

See Also:

• Constant Field Values

VALUE

public static final String VALUE

See Also:

• Constant Field Values

THEMES

public static final String THEMES

See Also:

• Constant Field Values

HTML_CONTENT

public static final String HTML_CONTENT

See Also:

• Constant Field Values

CHILDREN

public static final String CHILDREN

See Also:

• Constant Field Values

Constructor Details

SignalBindingFeature

public SignalBindingFeature(StateNode node)

Creates a SignalBindingFeature for the given node.

Parameters:

node - the node which supports the feature

Method Details

setBinding

public void setBinding(String key,
 Registration registration,
 Signal<?> signal)

Sets a binding for the given key.

Parameters:

key - the key

registration - the registration

signal - the signal

setBinding

public void setBinding(String key,
 Registration registration,
 Signal<?> signal,
 SerializableConsumer<?> writeCallback)

Sets a binding for the given key with a write callback.

Parameters:

key - the key

registration - the registration

signal - the signal

writeCallback - the callback to propagate value changes back, or null for a read-only binding

hasBinding

public boolean hasBinding(String key)

Checks whether there is a binding for the given key.

Parameters:

key - the key

Returns:

true if there is a binding for the given key, false otherwise

clearBindings

public void clearBindings(String keyPrefix)

Clears all bindings with keys starting with the given prefix.

Parameters:

keyPrefix - the key prefix

removeBinding

public void removeBinding(String key)

Removes the binding for the given key.

Parameters:

key - the key

getWriteCallback

public <T> SerializableConsumer<T> getWriteCallback(String key)

Gets the write callback for the given key.

Type Parameters:

T - the type of the consumer value

Parameters:

key - the key

Returns:

the write callback for the given key, or null if no callback is set

getSignal

public <T> Signal<T> getSignal(String key)

Gets the signal bound to the given key.

Type Parameters:

T - the type of the signal value

Parameters:

key - the key

Returns:

the signal bound to the given key, or null if no signal is bound

updateSignalByWriteCallback

public <T> boolean updateSignalByWriteCallback(String key,
 T oldValue,
 T newValue,
 SerializableBiPredicate<T,T> valueEquals,
 SerializableConsumer<T> revertCallback)

Updates the signal value by invoking the write callback for the given key. The callback is expected to update the signal value, and this method will check whether the signal value was updated to the expected new value. If the signal value differs from the expected new value after the callback, the revert callback will be invoked with the current signal value to revert the change.

Type Parameters:

T - the type of the signal value

Parameters:

key - the key for which to update the signal value

oldValue - the old value before the update, used for comparison in case of revert

newValue - the expected new value to be set by the write callback

valueEquals - a predicate to compare signal values for equality

revertCallback - a callback to revert the component value to the updated signal's value if the signal value does not match the expected new value after invoking the write callback

Returns:

true if the signal value was updated to the expected new value, false if a revert was performed