To show the config portal SSID in the callback, a global reference to the WiFiManager object was needed. To solve this, a pointer to the WiFiManager object is now passed to the callback. The feedback example is edited accordingly.

WiFiManager.h

@@ -83,7 +83,7 @@ class WiFiManager
     //sets a custom ip /gateway /subnet configuration
     void          setAPConfig(IPAddress ip, IPAddress gw, IPAddress sn);
     //called when AP mode and config portal is started
-    void          setAPCallback( void (*func)(void) );
+    void          setAPCallback( void (*func)(WiFiManager*) );
     //called when settings have been changed and connection was successful
     void          setSaveConfigCallback( void (*func)(void) );
 
@@ -138,7 +138,7 @@ class WiFiManager
     boolean       connect;
     boolean       _debug = true;
 
-    void (*_apcallback)(void) = NULL;
+    void (*_apcallback)(WiFiManager*) = NULL;
     void (*_savecallback)(void) = NULL;
 
     WiFiManagerParameter* _params[WIFI_MANAGER_MAX_PARAMS];