set EIO to version 4 in SocketIO examples

see Links2004#682

Author: Links2004

examples/esp8266/WebSocketClientSocketIO/WebSocketClientSocketIO.ino

@@ -88,7 +88,7 @@ void setup() {
  USE_SERIAL.printf("[SETUP] WiFi Connected %s\n", ip.c_str());
 
  // server address, port and URL
- socketIO.begin("10.11.100.100", 8880);
+ socketIO.begin("10.11.100.100", 8880, "/socket.io/?EIO=4");
 
  // event handler
  socketIO.onEvent(socketIOEvent);
@@ -106,7 +106,7 @@ void loop() {
  // creat JSON message for Socket.IO (event)
  DynamicJsonDocument doc(1024);
  JsonArray array = doc.to<JsonArray>();
- 
+
  // add evnet name
  // Hint: socket.on('event_name', ....
  array.add("event_name");
@@ -119,7 +119,7 @@ void loop() {
  String output;
  serializeJson(doc, output);
 
- // Send event 
+ // Send event
  socketIO.sendEVENT(output);
 
  // Print JSON for debugging

examples/esp8266/WebSocketClientSocketIOack/WebSocketClientSocketIOack.ino

@@ -49,7 +49,7 @@ void socketIOEvent(socketIOmessageType_t type, uint8_t * payload, size_t length)
  USE_SERIAL.println(error.c_str());
  return;
  }
- 
+
  String eventName = doc[0];
  USE_SERIAL.printf("[IOc] event name: %s\n", eventName.c_str());
 
@@ -58,7 +58,7 @@ void socketIOEvent(socketIOmessageType_t type, uint8_t * payload, size_t length)
  // creat JSON message for Socket.IO (ack)
  DynamicJsonDocument docOut(1024);
  JsonArray array = docOut.to<JsonArray>();
- 
+
  // add payload (parameters) for the ack (callback function)
  JsonObject param1 = array.createNestedObject();
  param1["now"] = millis();
@@ -68,7 +68,7 @@ void socketIOEvent(socketIOmessageType_t type, uint8_t * payload, size_t length)
  output += id;
  serializeJson(docOut, output);
 
- // Send event 
+ // Send event
  socketIO.send(sIOtype_ACK, output);
  }
  }
@@ -125,7 +125,7 @@ void setup() {
  USE_SERIAL.printf("[SETUP] WiFi Connected %s\n", ip.c_str());
 
  // server address, port and URL
- socketIO.begin("10.11.100.100", 8880);
+ socketIO.begin("10.11.100.100", 8880, "/socket.io/?EIO=4");
 
  // event handler
  socketIO.onEvent(socketIOEvent);
@@ -143,7 +143,7 @@ void loop() {
  // creat JSON message for Socket.IO (event)
  DynamicJsonDocument doc(1024);
  JsonArray array = doc.to<JsonArray>();
- 
+
  // add evnet name
  // Hint: socket.on('event_name', ....
  array.add("event_name");
@@ -156,7 +156,7 @@ void loop() {
  String output;
  serializeJson(doc, output);
 
- // Send event 
+ // Send event
  socketIO.sendEVENT(output);
 
  // Print JSON for debugging