re-reviewed

- callback has no return type
- private types for the wifimulti class
- explici WiFi.config(0U, 0U, 0U); for other APs
- formatting, whitespace, uppercase SSID

Author: mcspr

libraries/ESP8266WiFi/examples/WiFiMulti/WiFiMulti.ino

@@ -8,7 +8,7 @@
     - Connect to WiFi with strongest signal (RSSI)
     - Fall back to connect to next WiFi when a connection failed or lost
     - Fall back to connect to hidden SSID's which are not reported by WiFi scan
-    - Static IP assigned depending on which SSID is connected   
+    - Static IP assigned depending on which SSID is connected
 
     To enable debugging output, select in the Arduino iDE:
     - Tools | Debug Port: Serial
@@ -22,8 +22,6 @@ ESP8266WiFiMulti wifiMulti;
 // WiFi connect timeout per AP. Increase when connecting takes longer.
 const uint32_t connectTimeoutMs = 5000;
 
-SSID_selected_callback_t connectedToSSID(char *ssid);
-
 void setup() {
   // Don't save WiFi configuration in flash - optional
   WiFi.persistent(false);
@@ -39,21 +37,23 @@ void setup() {
   wifiMulti.addAP("ssid_from_AP_2", "your_password_for_AP_2");
   wifiMulti.addAP("ssid_from_AP_3", "your_password_for_AP_3");
 
-  wifiMulti.onSsidSelected(connectedToSSID);
+  wifiMulti.onSSIDSelected(connectedToSSID);
 
   // More is possible
 }
 
-SSID_selected_callback_t connectedToSSID(char *ssid)
-{
-  // On connecting the second WiFi, assign static IP using config(...).
-  // For other SSID (if config has not already been called) DHCP will be used.
-  if(strcmp(ssid, "ssid_from_AP_2") == 0) {
-    IPAddress ip2(192,168,1,123);
-    IPAddress gw2(192,168,1,1);
-    IPAddress subnet2(255,255,255,0);
+void connectedToSSID(const char *ssid) {
+  // On connecting to the second AP, assign static IP using config(...).
+  if (strcmp(ssid, "ssid_from_AP_2") == 0) {
+    IPAddress ip2(192, 168, 1, 123);
+    IPAddress gw2(192, 168, 1, 1);
+    IPAddress subnet2(255, 255, 255, 0);
     WiFi.config(ip2, gw2, subnet2);
+    return;
   }
+
+  // For other SSID DHCP will be used.
+  Wifi.config(0U, 0U, 0U);
 }
 
 void loop() {

libraries/ESP8266WiFi/src/ESP8266WiFiMulti.cpp

@@ -329,10 +329,14 @@ wl_status_t ESP8266WiFiMulti::connectWiFiMulti(uint32_t connectTimeoutMs)
             if (ssid == entry.ssid) {
                 DEBUG_WIFI_MULTI("[WIFIM] Connecting %s\n", ssid.c_str());
 
-                if(_onSsidSelected) _onSsidSelected(ssid.c_str());
+                // User-defined callback
+                if (_onSSIDSelected) {
+                    _onSSIDSelected(entry.ssid);
+                }
+
                 // Connect to WiFi
                 WiFi.begin(ssid, entry.passphrase, channel, bssid);
-                
+
                 // Wait for status change
                 if (waitWiFiConnect(connectTimeoutMs) == WL_CONNECTED) {
                     return WL_CONNECTED;
@@ -351,7 +355,11 @@ wl_status_t ESP8266WiFiMulti::connectWiFiMulti(uint32_t connectTimeoutMs)
         if (!connectSkipIndex[i]) {
             DEBUG_WIFI_MULTI("[WIFIM] Try hidden connect %s\n", entry.ssid);
 
-            if(_onSsidSelected) _onSsidSelected(entry.ssid);
+            // User-defined callback
+            if (_onSSIDSelected) {
+                _onSSIDSelected(entry.ssid);
+            }
+
             // Connect to WiFi
             WiFi.begin(entry.ssid, entry.passphrase);
 

libraries/ESP8266WiFi/src/ESP8266WiFiMulti.h

@@ -50,32 +50,31 @@
 #define WIFI_SCAN_TIMEOUT_MS        5000
 #endif
 
-struct WifiAPEntry {
-    char *ssid;
-    char *passphrase;
-};
-
-typedef std::vector<WifiAPEntry> WifiAPlist;
-typedef void (*SSID_selected_callback_t)(const char * ssid);
-
 class ESP8266WiFiMulti
 {
 public:
+    using SSIDSelectedCallback = void (*)(const char *ssid);
+
     ESP8266WiFiMulti();
     ~ESP8266WiFiMulti();
 
     bool addAP(const char *ssid, const char *passphrase = NULL);
     bool existsAP(const char *ssid, const char *passphrase = NULL);
-    void onSsidSelected(SSID_selected_callback_t cb) {  _onSsidSelected = cb;};
+    void onSSIDSelected(SSIDSelectedCallback callback) { _onSSIDSelected = callback; }
 
     wl_status_t run(uint32_t connectTimeoutMs=WIFI_CONNECT_TIMEOUT_MS);
 
     void cleanAPlist();
     int count() { return _APlist.size(); }
 private:
-    WifiAPlist _APlist;
+    struct WifiAPEntry {
+        char *ssid;
+        char *passphrase;
+    };
+
+    std::vector<WifiAPEntry> _APlist;
     bool _firstRun;
-    SSID_selected_callback_t _onSsidSelected = NULL;
+    SSIDSelectedCallback _onSSIDSelected = NULL;
 
     bool APlistAdd(const char *ssid, const char *passphrase = NULL);
     bool APlistExists(const char *ssid, const char *passphrase = NULL);