Package com.vaadin.classic.v8.server

Interface ClientConnector

All Known Subinterfaces:

Extension

All Known Implementing Classes:

AbsoluteLayout, AbstractClientConnector, AbstractComponent, AbstractComponentContainer, AbstractLayout, AbstractOrderedLayout, AbstractSingleComponentContainer, FormLayout, GridLayout, HorizontalLayout, Label, Panel, VerticalLayout

public interface ClientConnector

Legacy version of ClientConnector that resembles Vaadin 7/8's ClientConnector API as closely as possible in order to facilitate migration to newer versions of Vaadin.

Interface implemented by all legacy connectors that are capable of communicating with the client side.

Author:

Vaadin Ltd

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static class	ClientConnector.AttachEvent	Event fired before a connector is attached from the application.
static interface	ClientConnector.AttachListener	Interface for listening connector attach events.
static class	ClientConnector.DetachEvent	Event fired before a connector is detached from the application.
static interface	ClientConnector.DetachListener	Interface for listening connector attach events.

Method Summary

Modifier and Type	Method	Description
com.vaadin.flow.shared.Registration	addLegacyAttachListener(ClientConnector.AttachListener listener)	Add a listener for legacy connector attach events.
com.vaadin.flow.shared.Registration	addLegacyDetachListener(ClientConnector.DetachListener listener)	Add a listener for connector detach events.
void	attach()	Notifies the connector that it is connected to a VaadinSession (and therefore also to a UI).
void	beforeClientResponse(boolean initial)	Called before the response is written to client side.
void	detach()	Notifies the connector that it is detached from its VaadinSession.
boolean	isAttached()	Checks if the connector is attached to a VaadinSession.
boolean	isConnectorEnabled()	Checks if the communicator is enabled.
void	markAsDirty()	Marks that this classic component's state might have changed.
void	markAsDirtyRecursive()	Causes this classic component and all child components below it to be marked as dirty.

Method Detail

beforeClientResponse

void beforeClientResponse(boolean initial)

Called before the response is written to client side. Gives the legacy connector an opportunity to set computed/dynamic state values.

This is implemented for the legacy components to keep consistent behavior and e.g. legaze size calculations working.

NOTE: the parameter initial is false when the component is attached again to a new UI when PreserveOnRefresh is used.

Parameters:

initial - true if the client-side connector will be created and initialized after this method has been invoked. false if there is already an initialized client-side connector.

markAsDirty

void markAsDirty()

Marks that this classic component's state might have changed. When the framework is about to send new data to the client-side, it will run beforeClientResponse(boolean) for all legacy components that are marked as dirty.

markAsDirtyRecursive

void markAsDirtyRecursive()

Causes this classic component and all child components below it to be marked as dirty.

This should only be used in special cases, e.g when the state of a descendant depends on the state of an ancestor.

This will go through the whole component subtree, including any non-legacy components.

See Also:

markAsDirty()

addLegacyAttachListener

com.vaadin.flow.shared.Registration addLegacyAttachListener(ClientConnector.AttachListener listener)

Add a listener for legacy connector attach events. This could be migrated to AttachNotifier.addAttachListener(ComponentEventListener).

Parameters:

listener - the listener to add

Returns:

Registration for unregistering the listener

addLegacyDetachListener

com.vaadin.flow.shared.Registration addLegacyDetachListener(ClientConnector.DetachListener listener)

Add a listener for connector detach events. This could be migrated to DetachNotifier.addDetachListener(ComponentEventListener)

Parameters:

listener - the listener to add

Returns:

Registration for unregistering the listener

attach

void attach()

Notifies the connector that it is connected to a VaadinSession (and therefore also to a UI).

The caller of this method is ComponentUtil.onComponentAttach(Component, boolean)} if the parent is itself already attached to the session. If not, it's called when the parent is attached to the session. This method is always called before the connector's data is sent to the client-side for the first time.

The attachment logic is implemented in AbstractClientConnector.

detach

void detach()

Notifies the connector that it is detached from its VaadinSession.

isAttached

boolean isAttached()

Checks if the connector is attached to a VaadinSession.

Returns:

true if the connector is attached to a session, false otherwise

isConnectorEnabled

boolean isConnectorEnabled()

Checks if the communicator is enabled. An enabled communicator is allowed to receive messages from its counter-part.

Returns:

true if the connector can receive messages, false otherwise