Package com.vaadin.flow.dom

Interface DomListenerRegistration

All Superinterfaces:

Registration, Serializable

public interface DomListenerRegistration
extends Registration

A registration for configuring or removing a DOM event listener added to an element.

Since:

1.0

Author:

Vaadin Ltd

See Also:

Element.addEventListener(String, DomEventListener)

Method Summary

Modifier and Type	Method	Description
DomListenerRegistration	addEventData(String eventData)	Add a JavaScript expression for extracting event data.
default DomListenerRegistration	addEventDataElement(String eventData)	Add a JavaScript expression for extracting an element as event data.
default DomListenerRegistration	debounce(int timeout)	Configures this listener to be notified only when at least timeout milliseconds has passed since the last time the event was triggered.
DomListenerRegistration	debounce(int timeout, DebouncePhase firstPhase, DebouncePhase... rest)	Configures the debouncing phases for which this listener should be triggered.
default Set<DebouncePhase>	getDebouncePhases()	Gets the debouncing phases for which this listener should be triggered.
default int	getDebounceTimeout()	Gets the debounce timeout that is configured by debounce or throttle.
default String	getEventType()	Gets the event type that the listener is registered for.
String	getFilter()	Gets the currently set filter expression.
default DomListenerRegistration	mapEventTargetElement()	Marks that the DOM event should map the event.target to the closest corresponding Element on the server side, to be returned by DomEvent.getEventTarget().
default DomListenerRegistration	onUnregister(SerializableRunnable unregisterHandler)	Adds a handler that will be run when this registration is removed.
DomListenerRegistration	setDisabledUpdateMode(DisabledUpdateMode disabledUpdateMode)	Configure whether this listener will be called even in cases when the element is disabled.
DomListenerRegistration	setFilter(String filter)	Sets a JavaScript expression that is used for filtering events to this listener.
default DomListenerRegistration	synchronizeProperty(String propertyName)	Marks that the DOM event of this registration should trigger synchronization for the given property.
default DomListenerRegistration	throttle(int period)	Configures this listener to not be notified more often than period milliseconds.

Methods inherited from interface com.vaadin.flow.shared.Registration

remove

Method Detail

addEventData

DomListenerRegistration addEventData(String eventData)

Add a JavaScript expression for extracting event data. When an event is fired in the browser, the expression is evaluated and its value is sent back to the server. The expression is evaluated in a context where element refers to this element and event refers to the fired event. If multiple expressions are defined for the same event, their order of execution is undefined.

The result of the evaluation is available in DomEvent.getEventData() with the expression as the key in the JSON object. An expression might be e.g.

• element.value the get the value of an input element for a change event.
• event.button === 0 to get true for click events triggered by the primary mouse button.

Parameters:

eventData - definition for data that should be passed back to the server together with the event, not null

Returns:

this registration, for chaining

See Also:

for mapping an element, to map the to an element

setFilter

DomListenerRegistration setFilter(String filter)

Sets a JavaScript expression that is used for filtering events to this listener. When an event is fired in the browser, the expression is evaluated and an event is sent to the server only if the expression value is true-ish according to JavaScript type coercion rules. The expression is evaluated in a context where element refers to this element and event refers to the fired event.

An expression might be e.g. event.button === 0 to only forward events triggered by the primary mouse button.

Any previous filter for this registration is discarded.

Parameters:

filter - the JavaScript filter expression, or null to clear the filter

Returns:

this registration, for chaining

getFilter

String getFilter()

Gets the currently set filter expression.

Returns:

the current filter expression, or null if no filter is in use

See Also:

setFilter(String)

setDisabledUpdateMode

DomListenerRegistration setDisabledUpdateMode(DisabledUpdateMode disabledUpdateMode)

Configure whether this listener will be called even in cases when the element is disabled.

When used in combination with synchronizeProperty(String), the most permissive update mode for the same property will be effective. This means that there might be unexpected property updates for a disabled component if multiple parties independently configure different aspects for the same component. This is based on the assumption that if a property is explicitly safe to update for disabled components in one context, then the nature of that property is probably such that it's also safe to update in other contexts.

Parameters:

disabledUpdateMode - controls RPC communication from the client side to the server side when the element is disabled, not null

Returns:

this registration, for chaining

debounce

DomListenerRegistration debounce(int timeout,
                                 DebouncePhase firstPhase,
                                 DebouncePhase... rest)

Configures the debouncing phases for which this listener should be triggered. Debouncing is disabled and the set phases are ignored if timeout is set to 0.

This methods overrides the settings previously set through debounce(int), throttle(int) or debounce(int, DebouncePhase, DebouncePhase...).

Parameters:

timeout - the debounce timeout in milliseconds, or 0 to disable debouncing

firstPhase - the first phase to use

rest - any remaining phases to use

Returns:

this registration, for chaining

See Also:

DebouncePhase

debounce

default DomListenerRegistration debounce(int timeout)

Configures this listener to be notified only when at least timeout milliseconds has passed since the last time the event was triggered. This is useful for cases such as text input where it's only relevant to know the result once the user stops typing.

Debouncing is disabled if the timeout is set to 0.

This methods overrides the settings previously set through debounce(int), throttle(int) or debounce(int, DebouncePhase, DebouncePhase...).

Parameters:

timeout - the debounce timeout in milliseconds, or 0 to disable debouncing

Returns:

this registration, for chaining

throttle

default DomListenerRegistration throttle(int period)

Configures this listener to not be notified more often than period milliseconds.

Throttling is disabled if the period is set to 0.

This methods overrides the settings previously set through debounce(int), throttle(int) or debounce(int, DebouncePhase, DebouncePhase...).

Parameters:

period - the minimum period between listener invocations, or 0 to disable throttling

Returns:

this registration, for chaining

getDebounceTimeout

default int getDebounceTimeout()

Gets the debounce timeout that is configured by debounce or throttle.

Returns:

timeout in milliseconds, or 0 if debouncing is disabled

See Also:

debounce(int, DebouncePhase, DebouncePhase...), debounce(int), throttle(int)

getDebouncePhases

default Set<DebouncePhase> getDebouncePhases()

Gets the debouncing phases for which this listener should be triggered.

Returns:

debounce phases

See Also:

debounce(int, DebouncePhase, DebouncePhase...), debounce(int), throttle(int)

getEventType

default String getEventType()

Gets the event type that the listener is registered for.

Returns:

DOM event type of the listener

onUnregister

default DomListenerRegistration onUnregister(SerializableRunnable unregisterHandler)

Adds a handler that will be run when this registration is removed.

Parameters:

unregisterHandler - the handler to run when the registration is removed, not null

Returns:

this registration, for chaining

Since:

1.3

synchronizeProperty

default DomListenerRegistration synchronizeProperty(String propertyName)

Marks that the DOM event of this registration should trigger synchronization for the given property.

Parameters:

propertyName - the name of the property to synchronize, not null or ""

Returns:

this registration, for chaining

mapEventTargetElement

default DomListenerRegistration mapEventTargetElement()

Marks that the DOM event should map the event.target to the closest corresponding Element on the server side, to be returned by DomEvent.getEventTarget().

Returns:

this registration, for chaining

Since:

9.0

addEventDataElement

default DomListenerRegistration addEventDataElement(String eventData)

Add a JavaScript expression for extracting an element as event data. When an event is fired in the browser, the expression is evaluated and if it returns an element from DOM, the server side element or closest parent element is sent to server side. The expression is evaluated in a context where element refers to this element and event refers to the fired event. If multiple expressions are defined for the same event, their order of execution is undefined.

The result of the evaluation is available in DomEvent.getEventDataElement(String) with the expression as the key in the JSON object.

In case you want to get the event.target element to the server side, use the mapEventTargetElement() method to get it mapped and the DomEvent.getEventTarget() to fetch the element.

Parameters:

eventData - definition for element that should be passed back to the server together with the event, not null

Returns:

this registration, for chaining

Since:

9.0

See Also:

to map the to an element