add missing user agent method from stash

Author: toddtreece

src/AdafruitIO.cpp

@@ -22,6 +22,7 @@ AdafruitIO::AdafruitIO(const char *user, const char *key)
   _err_sub = 0;
   _throttle_sub = 0;
   _packetread_timeout = 100;
+  _user_agent = 0;
 
   _init();
 }
@@ -37,6 +38,7 @@ AdafruitIO::AdafruitIO(const __FlashStringHelper *user, const __FlashStringHelpe
   _err_sub = 0;
   _throttle_sub = 0;
   _packetread_timeout = 100;
+  _user_agent = 0;
 
   _init();
 }
@@ -215,6 +217,21 @@ char* AdafruitIO::version()
   return _version;
 }
 
+char* AdafruitIO::userAgent()
+{
+  if(!_user_agent) {
+    _user_agent = (char *)malloc(sizeof(char) * (strlen(version()) + strlen(boardType()) + strlen(connectionType()) + 24));
+    strcpy(_user_agent, "AdafruitIO-Arduino/");
+    strcat(_user_agent, version());
+    strcat(_user_agent, " (");
+    strcat(_user_agent, boardType());
+    strcat(_user_agent, "-");
+    strcat(_user_agent, connectionType());
+    strcat(_user_agent, ")");
+  }
+  return _user_agent;
+}
+
 aio_status_t AdafruitIO::mqttStatus()
 {
   // if the connection failed,

src/AdafruitIO.h

@@ -58,6 +58,7 @@ class AdafruitIO {
     char* boardID();
     const char* boardType();
     char* version();
+    char* userAgent();
     virtual const char* connectionType() = 0;
 
   protected:
@@ -81,6 +82,7 @@ class AdafruitIO {
 
     char *_err_topic;
     char *_throttle_topic;
+    char *_user_agent;
 
     Adafruit_MQTT_Subscribe *_err_sub;
     Adafruit_MQTT_Subscribe *_throttle_sub;