add function to send WS ping

sendPing();

#130

src/WebSocketsClient.cpp

@@ -207,6 +207,24 @@ bool WebSocketsClient::sendBIN(const uint8_t * payload, size_t length) {
     return sendBIN((uint8_t *) payload, length);
 }
 
+/**
+ * sends a WS ping to Server
+ * @param payload uint8_t *
+ * @param length size_t
+ * @return true if ping is send out
+ */
+bool WebSocketsClient::sendPing(uint8_t * payload, size_t length) {
+    if(clientIsConnected(&_client)) {
+        return sendFrame(&_client, WSop_ping, payload, length);
+    }
+    return false;
+}
+
+bool WebSocketsClient::sendPing(String & payload) {
+    return sendPing((uint8_t *) payload.c_str(), payload.length());
+}
+
+
 /**
  * disconnect one client
  * @param num uint8_t client id

src/WebSocketsClient.h

@@ -69,6 +69,9 @@ class WebSocketsClient: private WebSockets {
         bool sendBIN(uint8_t * payload, size_t length, bool headerToPayload = false);
         bool sendBIN(const uint8_t * payload, size_t length);
 
+        bool sendPing(uint8_t * payload = NULL, size_t length = 0);
+        bool sendPing(String & payload);
+
         void disconnect(void);
 
         void setAuthorization(const char * user, const char * password);

src/WebSocketsServer.cpp

@@ -283,6 +283,57 @@ bool WebSocketsServer::broadcastBIN(const uint8_t * payload, size_t length) {
     return broadcastBIN((uint8_t *) payload, length);
 }
 
+
+/**
+ * sends a WS ping to Client
+ * @param num uint8_t client id
+ * @param payload uint8_t *
+ * @param length size_t
+ * @return true if ping is send out
+ */
+bool WebSocketsServer::sendPing(uint8_t num, uint8_t * payload, size_t length) {
+    if(num >= WEBSOCKETS_SERVER_CLIENT_MAX) {
+        return false;
+    }
+    WSclient_t * client = &_clients[num];
+    if(clientIsConnected(client)) {
+        return sendFrame(client, WSop_ping, payload, length);
+    }
+    return false;
+}
+
+bool WebSocketsServer::sendPing(uint8_t num, String & payload) {
+    return sendPing(num, (uint8_t *) payload.c_str(), payload.length());
+}
+
+/**
+ *  sends a WS ping to all Client
+ * @param payload uint8_t *
+ * @param length size_t
+ * @return true if ping is send out
+ */
+bool WebSocketsServer::broadcastPing(uint8_t * payload, size_t length) {
+    WSclient_t * client;
+    bool ret = true;
+    for(uint8_t i = 0; i < WEBSOCKETS_SERVER_CLIENT_MAX; i++) {
+        client = &_clients[i];
+        if(clientIsConnected(client)) {
+            if(!sendFrame(client, WSop_ping, payload, length)) {
+                ret = false;
+            }
+        }
+#if (WEBSOCKETS_NETWORK_TYPE == NETWORK_ESP8266)
+        delay(0);
+#endif
+    }
+    return ret;
+}
+
+bool WebSocketsServer::broadcastPing(String & payload) {
+    return broadcastPing((uint8_t *) payload.c_str(), payload.length());
+}
+
+
 /**
  * disconnect all clients
  */

src/WebSocketsServer.h

@@ -81,6 +81,12 @@ public:
         bool broadcastBIN(uint8_t * payload, size_t length, bool headerToPayload = false);
         bool broadcastBIN(const uint8_t * payload, size_t length);
 
+        bool sendPing(uint8_t num, uint8_t * payload = NULL, size_t length = 0);
+        bool sendPing(uint8_t num, String & payload);
+
+        bool broadcastPing(uint8_t * payload = NULL, size_t length = 0);
+        bool broadcastPing(String & payload);
+
         void disconnect(void);
         void disconnect(uint8_t num);