On Socket.IO Message

Plugin: Socket.IO | Mode: Listen

React on messages sent from a website or Web APP via a Socket.IO Namespace.

Settings

Namespace

The Socket.IO namespace for which incoming messages are to be listened to.

You can add namespaces in the Socket.IO Plugin settings.

room

optional

The id of the room in which incoming messages are to be listened to. Only messages from clients that have joined the room with join are responded to.

If you have linked a data item to a room via the create topic, you can also specify the data item variable here.

If you do not specify a room, messages from all clients that are linked to the namespace will be listened to.

topic

The topic of the message.

if

optional

Create a condition that the incoming message must fulfil and a response if the condition is met. If a condition matches, the the specified next state will be triggered or a message will be returned to the client (respond).

If the potential message payload contains a JS object, you can use field to specify which property in the object you want to check for a condition.

Use dot (.) notation in field to name nested properties in the object.

You can find out more about if conditions in the chapter Conditions Queries with Conditions.

The value of the if condition is the incoming message.

With respond you can react directly to the message. If the corresponding condition is met, the respond message is returned to the client via socket.io callback or emitWithAck.

To return a list or an object select string and use javascript array or object syntax. Example:

["rope", "bracelet", "gemstone"]

or

{color: "green", score: 5, friends: ["Grace", "Ada", "Tim"]}

else

optional

Go to the next state or return a value with respond if there is no match in any of the if conditions.

If you have not specified an if condition, else is triggered for every message sent on the specified namespace and room (optional) on the specified topic.

priority

optional

It is possible that several On Socket Message actions on the same namespace, in the same room listen to the same topic. In this case, the respond message of the action with the highest priority is returned to the client.

If priority is the same for 2 actions, the respond of the action that was activated last is returned.

keep listening and queue

Mute the On Socket Message listener instead of closing it completely when the state containing On Socket Message is exited.

The action will then no longer respond to incoming messages, but the messages will be stored in a queue.

If the state containing this On Socket Message action is called again, the saved messages are checked first before the listener starts listening for further messages.

Info

In the chapter on Loops you will find additional information on keep listening and queue

Action Data

You can access the last received Socket.IO message via the On Socket.IO Message action data variable. Use for example:

[[state.MyState.onSocketioMessage_1.message]]

To access the last received message of the upmost On Socket.IO Message action in the MyState state.

match

The message or the part of the message that matched in an if condition in the On Socket.IO Message action.

Example:

part of the message

message

Total latest message on the topic that was received by the On Socket.IO Message action.

Example:

This is not the only part of the message.

room

The room id of the room in which the message was received.

topic

The topic of the latest message that was received.

Example:

someTopic

Example

In the Socket.IO plugin documentation you will find an example of how to use the On Socket.IO Message action.