Closed
Conversation
The "loopback" flag is used to emit messages on the local endpoint of a socket; e.g., allowing the server to send a message to the server's handler directly. This is especially useful in conjunction with rooms, as it allows the server to proactively trigger behavior for each socket in a room without having to maintain a separate list of said sockets or relying on the client endpoint to trigger the behavior.
This was referenced Feb 28, 2024
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
1 participant
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
The kind of change this PR does introduce
Current behaviour
It is not possible to send messages to the local (server) endpoint. In scenarios where rooms/broadcasts are used, this requires the server to maintain a separate room->socket mapping so that administrative actions can be performed (e.g., close all sockets in room 'foo').
New behaviour
With this change (and related PR socketio/socket.io-adapter#56), it is possible to emit/broadcast messages that are handled by the local (server) endpoint by inserting
.loopbackinto the emit syntax. On connect, the server can add handlers for messages that originate server-side, and later broadcast those messages in order to effect administrative actions (e.g., close all sockets in room 'foo') without maintaining independent mappings.Other information (e.g. related issues)
socketio/socket.io-adapter#56 must be committed before this change, as
socket.io-adapteris used in tests and must honour theloopbackflag.