added wifi network scan

Arduino/CanGrow/include/CanGrow_Webserver.h

@@ -44,14 +44,15 @@
 #include "Webserver/Page_wifi.h"
 
 
-
-
 AsyncWebServer webserver(80);
 // log incoming requests
 LoggingMiddleware requestLogger;
 
 
-/* 404 error site - this is also a good example for a simple WebPage */
+/*
+ * 404 error page begins
+ */
+ 
 const char* Page_404_HTML PROGMEM = R"(%HEADER%
 <div class='warnmsg'><h1>&#10071; &#65039; 404 - not found</h1></div>
 %FOOTER%)";
@@ -66,6 +67,12 @@ void WebserverNotFound(AsyncWebServerRequest* request) {
   request->send(404, "text/html", Page_404_HTML, Proc_WebPage_404);
 }
 
+/*
+ * 404 error page ends
+ */
+
+
+
 /*
  * setup all the webhandlers
  */
@@ -88,7 +95,18 @@ void SetupWebserver() {
   
   webserver.onNotFound(WebserverNotFound);
 
+  // Workaround, see comment at
+  // https://github.com/mathieucarbou/ESPAsyncWebServer/blob/main/docs/index.md#scanning-for-available-wifi-networks
+  // call the network scan once, so there are some values at the first call
+  // of the wifi settings page. otherwise the first call of the wifi scan would return
+  // an empty list of networks
+  Serial.println(":: [Webserver] call [wifi:ScanNetworks] to workaround empty results bug");
+  WebPage_wifi_ScanNetworks();
+
   webserver.begin();
   Serial.println(":: [Webserver] ready to serve");
+  
+
+  
 }
 

Arduino/CanGrow/include/Webserver/Page_wifi.h

@@ -30,13 +30,39 @@
 
 #include "Page_wifi_HTML.h"
 
+String WebPage_wifi_ScanNetworks() {
+  String html;
   
+  Serial.println(":: [Webserver:wifi:ScanNetworks] scanning for available networks:");
+  // https://github.com/mathieucarbou/ESPAsyncWebServer/blob/main/docs/index.md#scanning-for-available-wifi-networks
+  int n = WiFi.scanComplete();
+  if(n == -2){
+    WiFi.scanNetworks(true);
+  } else if(n){
+    for (int i = 0; i < n; ++i){
+      html += "<option value='" + WiFi.SSID(i) + "'>" + WiFi.SSID(i) + "</option>";
+      Serial.print(":: [Webserver:wifi:ScanNetworks]   - ");
+      Serial.println(WiFi.SSID(i));
+    }
+    WiFi.scanDelete();
+    if(WiFi.scanComplete() == -2){
+      WiFi.scanNetworks(true);
+    }
+  }
+  return html;
+}
 
 // https://techtutorialsx.com/2018/07/23/esp32-arduino-http-server-template-processing-with-multiple-placeholders/
 String Proc_WebPage_wifi(const String& var) {
   if(TestHeaderFooter(var)) {
     return AddHeaderFooter(var);
-    //SNIP_CURRSETTINGS
+    //CURRENT_SETTINGS
+  } else if(var == "CURRENT_SETTINGS") {
+    if(strlen(configWifi.ssid) > 0) {
+      return String(Page_wifi_HTML_CURRENT_SETTINGS);
+    } else {
+      return String();
+    }
   } else if(var == "CONFIGWIFI_SSID") {
     return String(configWifi.ssid);
   } else if(var == "CONFIGWIFI_DHCP") {
@@ -50,7 +76,7 @@ String Proc_WebPage_wifi(const String& var) {
   } else if(var == "CONFIGWIFI_DNS") {
     return String(WiFi.dnsIP().toString());
   } else if(var == "WIFI_LIST") {
-    return String("");
+    return String(WebPage_wifi_ScanNetworks());
   } else {
     return String();
   }

Arduino/CanGrow/include/Webserver/Page_wifi_HTML.h

@@ -29,7 +29,7 @@
 
 const char* Page_wifi_HTML PROGMEM = R"(%HEADER%
 <h2>&#128225; WiFi settings</h2>
-%SNIP_CURRSETTINGS%
+%CURRENT_SETTINGS%
 <p>Select your wifi network from the SSID list.
 <br>To use DHCP leave IP, Subnet, Gateway and DNS fields blank!</p>
 <form method='post' action='/wifiSettings/save'>
@@ -46,7 +46,7 @@ DNS: <input type='text' name='configWifi.dns'><br>
 </form>
 %FOOTER%)";
 
-const char* Page_wifi_HTML_curSettings PROGMEM = R"(<u>Current Settings:</u><br>WiFi SSID: <b>%CONFIGWIFI_SSID%</b><br>
+const char* Page_wifi_HTML_CURRENT_SETTINGS PROGMEM = R"(<u>Current Settings:</u><br>WiFi SSID: <b>%CONFIGWIFI_SSID%</b><br>
 Use DHCP: <b>%CONFIGWIFI_DHCP%</b><br>
 IP address: <b>%CONFIGWIFI_IP%</b><br>
 Subnet mask: <b>%CONFIGWIFI_NETMASK%</b><br>