This library is deprecated. You can directly use the WebSockets library (https://github.com/Links2004/arduinoWebSockets). It supports a SocketIOclient class. See the example there.

socket.io-client

A socket.io-client implementation for ESP8266 and Arduino.

Index

• Install
• Functions
• Miscellaneous
• Example
• Contribution

Install

💡 This library uses lstdc++

To compile you have to add a reference to the linker. To do so edit platform.txt in $ARDUINO_IDE/hardware/esp8266com/esp8266 and add '-lstdc++' to the line

compiler.c.elf.libs= ...

💡 Note: See ESP8266 for Arduino IDE (xtensa-lx106-elf-gcc) and std::map linking error.

Add library

Best thing is to use the Arduino Library Manager.

1. Go to Sketch > Include Library > Manage Libraries.
2. Install WebSockets by Markus Sattler
3. Install SocketIoClient
4. Select Sketch > Include Library > SocketIoClient

Functions

1. SocketIoClient::begin()
2. SocketIoClient::beginSSL()
3. SocketIoClient::disconnect()
4. SocketIoClient::emit()
5. SocketIoClient::loop()
6. SocketIoClient::on()
7. SocketIoClient::remove()
8. SocketIoClient::setAuthorization()

SocketIoClient::begin(host[, port, path])

Open connection to socket.io server.

Parameter

host url to socket.io server port port to connect on. Defaults to 80 or 443 (SSL) path path to connect to on server. Defaults to "/socket.io/?transport=websocket"

Example

socket.begin("my.socket-io.server", 443, "/socket.io/?transport=websocket");

SocketIoClient::beginSSL(host[, port, path, fingerprint])

Open SSL connection to socket.io server.

Parameter

host url to socket.io server port port to connect on. Defaults to 80 or 443 (SSL) path path to connect to on server. Defaults to "/socket.io/?transport=websocket" fingerprint the SSL fingerprint. Defaults to ""

Example

socket.beginSSL("my.socket-io.server", 443, "/socket.io/?transport=websocket", "26 96 1C 2A 51 07 FD 15 80 96 93 AE F7 32 CE B9 0D 01 55 C4");

SocketIoClient::disconnect()

Disconnect from the server.

Example

socket.disconnect();

SocketIoClient::emit(event, payload)

Emits an event to the server.

Parameter

event name of the event to be emitted payload string of the payload to be sent with the event. Plain strings and object property names should be encapsulated in quotes.

Example

socket.emit("plainString", "\"this is a plain string\"");
socket.emit("jsonObject", "{\"foo\":\"bar\"}");

SocketIoClient::loop()

Processes the websocket. Should be called in Arduino main loop.

SocketIoClient::on(event, callback)

Binds a function to an event.

Parameter

event name of the event to bind to callback callback function to call when the event is triggered Function signature must be

void (const char * payload, size_t length)

Example

void event(const char * payload, size_t length) {
	// do stuff
}
socket.on("event", event);

Supported default events:

• connect - when user is connected to server
• disconnect - when user is disconnected from the server

SocketIoClient::remove(event)

Removes the previously added event.

Parameter

event name of the event binded

Example

socket.remove("event");

SocketIoClient::setAuthorization(username, password)

Set HTTP Basic auth username and password.

Example

socket.setAuthorization("username", "password");

Miscellaneous

To go along with the socket.io-client implementation of socket.io the connect event is triggered upon successfully opened connection to server. To utilize simply add

socket.on("connect", handler)

Likewise, disconnect event is triggered upon terminated connection.

Example

See Example

Contribution

Based on the great work of Links2004 / arduinoWebSockets.