com.vaadin.flow.internal.nodefeature

Class ReturnChannelMap

java.lang.Object

com.vaadin.flow.internal.nodefeature.NodeFeature

com.vaadin.flow.internal.nodefeature.ServerSideFeature

com.vaadin.flow.internal.nodefeature.ReturnChannelMap

All Implemented Interfaces:

Serializable

public class ReturnChannelMap
extends ServerSideFeature

Server-side node feature that keeps track of the return channels registered for a state node.

Return channels are only tracked on the server. The client doesn't need to know which channels are registered - it only passes the channel id back to the server. The server checks that the received channel id is (still) valid and logs a warning if it isn't.

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

Since:

2.0

Author:

Vaadin Ltd

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
ReturnChannelMap(StateNode node) Creates a new return channel map for the given state node.

Method Summary

Modifier and Type	Method and Description
ReturnChannelRegistration	get(int channelId) Gets the return channel registration registered with the provided id, or null if no channel is registered with that id.
ReturnChannelRegistration	registerChannel(SerializableBiConsumer<elemental.json.JsonArray,ReturnChannelRegistration> handler) Registers a new channel based on a callback that receives the provided arguments and the channel registration when a message is passed to the channel.
ReturnChannelRegistration	registerChannel(SerializableConsumer<elemental.json.JsonArray> handler) Registers a new channel based on a callback that receives the provided arguments when a message is passed to the channel.

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

Constructor Detail

ReturnChannelMap

public ReturnChannelMap(StateNode node)

Creates a new return channel map for the given state node.

Parameters:

node - the owning state node, not null

Method Detail

registerChannel

public ReturnChannelRegistration registerChannel(SerializableConsumer<elemental.json.JsonArray> handler)

Registers a new channel based on a callback that receives the provided arguments when a message is passed to the channel.

The returned registration can be passed to the client as a parameter to various executeJavaScript methods. The client side representation of the registration will be a function that will send a message to the provided handler.

Parameters:

handler - the argument handler, not null

Returns:

a return channel registration

registerChannel

public ReturnChannelRegistration registerChannel(SerializableBiConsumer<elemental.json.JsonArray,ReturnChannelRegistration> handler)

Registers a new channel based on a callback that receives the provided arguments and the channel registration when a message is passed to the channel. The purpose of passing the registration to the handler is to allow the channel to unregister itself when it receives a message.

The returned registration can be passed to the client as a parameter to various executeJavaScript methods. The client side representation of the registration will be a function that will send a message to the provided handler.

Parameters:

handler - the argument and registration handler, not null

Returns:

a return channel registration

get

public ReturnChannelRegistration get(int channelId)

Gets the return channel registration registered with the provided id, or null if no channel is registered with that id.

Parameters:

channelId - the channel id to look for

Returns:

a return channel registration, or null if no registration exists for the given id