WiFiManager OnDemand Portal with web server

OnDemandConfigPortal.ino

#include <ESP8266WiFi.h>          //https://github.com/esp8266/Arduino

//needed for library
#include <ESP8266WebServer.h>
#include <DNSServer.h>
#include <WiFiManager.h>          //https://github.com/tzapu/WiFiManager

#define GPIO0 0
#define GPIO2 2

unsigned long previousMillis = 0;

WiFiClient client;
ESP8266WebServer server(80);

void handle_root()
{
  server.send(200, "text/plain", "Hello from the esp8266, read from /gpio0 or /gpio2");
  delay(100);
}

void WiFiStatus() {
    byte percentQ = 0;
    
    if (WiFi.RSSI() <= -100) {
      percentQ = 0;
    } else if (WiFi.RSSI() >= -50) {
      percentQ = 100;
    } else {
      percentQ = 2 * (WiFi.RSSI() + 100);
    }

    Serial.println("");
    Serial.println("WiFi Status");
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP());
    Serial.print("MAC address: ");
    Serial.println(WiFi.macAddress());
    Serial.print("SSID: ");
    Serial.println(WiFi.SSID());
    Serial.print("Signal Strength (%): ");
    Serial.println(percentQ);
}

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("\n Starting");

  // Configure our GPIO's as inputs
  pinMode(GPIO0, INPUT_PULLUP);
  pinMode(GPIO2, INPUT_PULLUP);  

  WiFi.mode(WIFI_STA);
  WiFi.begin("ssid", "psk");
    
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");  
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());

  server.on("/", handle_root);
  
  server.on("/gpio0", [](){  // if you add this subdirectory to your webserver call, you get text below :)
      server.send(200, "text/plain", "Current value of GPIO0: "+String(digitalRead(GPIO0)));            // send to someones browser when asked
  });

  server.on("/gpio2", [](){  // if you add this subdirectory to your webserver call, you get text below :)
      server.send(200, "text/plain", "Current value of GPIO2: "+String(digitalRead(GPIO2)));               // send to someones browser when asked
  });

  server.begin();
  Serial.println("");
  Serial.println("HTTP server started");

}


void loop() {

  // Causes the WiFi Status to be repeated every 10 seconds. Probably not necessary.
  if ( millis() - previousMillis > 10000 ) {
    WiFiStatus();
    Serial.println("GPIO0 state: "+String(digitalRead(GPIO0)));
    Serial.println("GPIO2 state: "+String(digitalRead(GPIO2)));
    previousMillis = millis();
  }

  if ( !digitalRead(GPIO0) ) { // Reprogram button was pressed

    //server.~ESP8266WebServer();
    WiFi.softAPdisconnect(true);
    delay(500);
    //WiFi.mode(WIFI_STA);
    //WiFi.disconnect();
    //delay(500);
    delete &server;
    WiFi.disconnect();

    //WiFiManager
    //Local intialization. Once its business is done, there is no need to keep it around
    WiFiManager wifiManager;

    //reset settings - for testing
    //wifiManager.resetSettings();

    //sets timeout until configuration portal gets turned off
    //useful to make it all retry or go to sleep
    //in seconds
    //wifiManager.setTimeout(120);

    //it starts an access point with the specified name
    //here  "AutoConnectAP"
    //and goes into a blocking loop awaiting configuration

    //WITHOUT THIS THE AP DOES NOT SEEM TO WORK PROPERLY WITH SDK 1.5 , update to at least 1.5.1
    //WiFi.mode(WIFI_STA);
    
    if (!wifiManager.startConfigPortal("ESP8266AutoConnectAP", "electricity")) {
      Serial.println("failed to connect and hit timeout");
      delay(3000);
      //reset and try again, or maybe put it to deep sleep
      ESP.reset();
      delay(5000);
    }

    //if you get here you have connected to the WiFi
    Serial.println("connected...yeey :)");
  }


  server.handleClient();

}