Internot.ino

//
// a modified version of "ESP_AsyncFSBrowser.ino" example
//     in "ESPAsyncWebServer" library of Hristo Gochkov (me-no-dev @ github)
//
// licensed under "LPGL-3.0"
//

//
// at first, set of modifications suggested by the gist, https://gist.github.com/dsteinman/f792f0af25ce6d7d1db4b62d29dd4d9e, applied.
//
// --> Hristo Gochkov's original code only supports "esp8266" at the time of this writing.
//     Suggested patched version makes the same ex. code runnable on "esp32"
//
// --> refer to the issue @ https://github.com/me-no-dev/ESPAsyncWebServer/issues/327#issuecomment-382811459
//

//
// afterwards, more changes applied for
//    (2) use a captive portal
//

/***************************************/
/*  CONFIGURATIONS                     */
/***************************************/
const bool is_AP = true; // Set to false to just run as webserver, convenient for testing.

const char* ssid = "YOUR_SSID"; // Wifi credentials
const char* password = "YOUR_PASSWORD";

// AP identifications & credentials
String AP_ssid = "Internot";

/***************************************/
/*  ALL HEADERS and GLOBAL VARIABLES   */
/***************************************/

//file system
#include <FS.h>
#include <SPIFFS.h>

//wifi / tcp
#include <WiFi.h>
#include <WiFiClient.h>
#include <AsyncTCP.h>

//dns server
#include <DNSServer.h>
DNSServer dnsServer;

// json
#include <ArduinoJson.h>

// captive portal -> a self-assigned ip
IPAddress apIP(192, 168, 4, 1);

//web server
#include <ESPAsyncWebServer.h> // <-- this includes, also, "AsyncWebSocket.h" and "AsyncEventSource.h"
AsyncWebServer server(80);

DynamicJsonDocument doc(2048);

String IP = "";

void setup() {
  //serial monitoring
  Serial.begin( 115200 );
  Serial.setDebugOutput( true );
  delay( 10 );
  Serial.println( "START" );

  SPIFFS.begin();   //file system
  JSONFromFile();
  AP_ssid = getSSIDFromFile();

  //wifi
  if ( is_AP ) {
    WiFi.mode( WIFI_AP );

    //start ap
    WiFi.softAPConfig( apIP, apIP, IPAddress( 255, 255, 255, 0 ) );
    WiFi.softAP( AP_ssid.c_str(), NULL, 6 ); //channel selection : 6 (choose one among 6-13 for world-wide accessibility)

    //my ip
    delay( 500 );
    Serial.print( "Captive Network. IP address:" ); Serial.println( WiFi.softAPIP() );
    IP = WiFi.softAPIP().toString();
  } else {
    WiFi.mode( WIFI_STA );
    WiFi.begin( ssid, password );

    while ( WiFi.status() != WL_CONNECTED ) {
      delay( 500 );
      Serial.print( "." );
    }

    Serial.print( "Connected to " );  Serial.println( ssid );
    Serial.print( "IP address: " ); Serial.println( WiFi.localIP() );
    IP = WiFi.localIP().toString();
  }

  //dns service (captive portal)
  dnsServer.start( 53, "*", apIP ); // reply with provided IP(apIP) to all("*") DNS request

  server.on( "/post", HTTP_ANY, []( AsyncWebServerRequest * request ) {
    //List all parameters
    Serial.println( "Request for /post" );
    JsonObject message = doc.createNestedObject(); // create object for storing the message
    int params = request->params();
    for ( int i = 0; i < params; i++ ) {
      AsyncWebParameter* p = request->getParam( i );
      if ( p->isFile() ) { //p->isPost() is also true
        Serial.printf( "FILE[%s]: %s, size: %u\n", p->name().c_str(), p->value().c_str(), p->size() );
      } else if ( p->isPost() ) {
        String key = p->name().c_str();
        String value = p->value().c_str();
        Serial.printf( "POST[%s]: %s\n", key, value );
        message[ key ] = value;
      } else {
        Serial.printf( "GET[%s]: %s\n", p->name().c_str(), p->value().c_str() );
      }
    }

    JSONToFile(); // save the message to file
    request->redirect( String( "http://" ) + IP + "/" ); // redirect back to the form
  } );

  server.on( "/messages", HTTP_ANY, [](AsyncWebServerRequest * request ) {
    //List all parameters
    Serial.println( "Request for /messages" );

    AsyncResponseStream *response = request->beginResponseStream( "text/plain" );
    response->addHeader( "Server", "ESP Async Web Server" );
    response->addHeader( "Access-Control-Allow-Origin", "*" ); // allows for testing from a static file:// url
    String json = "";
    serializeJson( doc, json );
    response->print( json );
    request->send( response ); //send the response last
  });

  //serve-root
  server.serveStatic( "/", SPIFFS, "/" ).setDefaultFile( "index.htm" );

  server.onNotFound( onRequest );

  //start the web service
  server.begin();
}

void onRequest( AsyncWebServerRequest * request ) {
  //Handle Unknown Request
  Serial.println( "Unknown request. Redirect to default" );
  request->redirect( String( "http://" ) + apIP.toString() + "/" );
}

void JSONFromFile() {
  File file = SPIFFS.open( "/messages.json", FILE_READ );
  String s = file.readString();
  deserializeJson( doc, s );
  //  JsonArray array = doc.to<JsonArray>();
  file.close();
}

void JSONToFile() {
  File file = SPIFFS.open( "/messages.json", FILE_WRITE );
  String json = "";
  serializeJson( doc, json );
  if ( ! file.print( json ) ) {
    Serial.println( "File write failed" );
  }
  file.close();
}

String getSSIDFromFile() {
  String ssid = "Internot";
  File root = SPIFFS.open( "/" );
  File file = root.openNextFile();
  while (file) {
    String n = file.name();
    int dot = n.lastIndexOf(".");
    String ext = n.substring( dot );
    if ( ext == ".ssid" ) {
			// if the file starts with a "/", skip it
			// older versions of spiFFS add a "/" to the beginning of the file name
			if ( n[0] == '/' ) {
				ssid = n.substring( 1, dot ); // first index is 1 to skip the "/"
			} else {
				ssid = n.substring( 0, dot ); // otherwise not :)
			}
    }
    file = root.openNextFile();
  }
  return ssid;
}

void loop() {
  dnsServer.processNextRequest(); // handle DNS
}