ESP32 WebServer Library – on()

/*
 * Author: Avant Maker
 * Date: March 17, 2025
 * Version: 1.0
 * License: MIT 
 * 
 * Description: 
 * This example demonstrates how to use ESP32 WebServer Library's 
 * on() method to set up a simple web server that responds to any
 * request to the root URL ("/") with a "Hello, World!" message.
 *
 * Code Source:
 * This example code is sourced from the Comprehensive Guide
 * to the ESP32 Arduino Core Library, accessible on AvantMaker.com.
 * For additional code examples and in-depth documentation related to
 * the ESP32 Arduino Core Library, please visit:
 *
 * https://avantmaker.com/home/all-about-esp32-arduino-core-library/
 *
 * AvantMaker.com, your premier destination for all things
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
 * to empowering makers, learners, and enthusiasts with
 * the resources they need to bring their nnovative ideas to life.
 */


#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "your-SSID";          // Replace with your Wi-Fi SSID
const char* password = "your-PASSWORD";  // Replace with your Wi-Fi password

WebServer server(80);

void handleRoot() {
    server.send(200, "text/plain", "AvantMaker.com ESP32 Web Server Demo");
}

void setup() {
    Serial.begin(115200);
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("WiFi Connected:");
    Serial.print("IP: ");
    Serial.println(WiFi.localIP());
    server.on("/", handleRoot);
    server.begin();
}

void loop() {
    server.handleClient();
}

/*
 * Author: Avant Maker
 * Date: March 24, 2025
 * Version: 1.0
 * License: MIT 
 * 
 * Description: 
 * This example demonstrates how to use ESP32 WebServer Library's 
 * on() method to respond only to HTTP GET requests to "/info".
 * It’s useful when you want to restrict responses to specific
 * HTTP methods, such as serving data only on GET requests.
 *
 * Code Source:
 * This example code is sourced from the Comprehensive Guide
 * to the ESP32 Arduino Core Library, accessible on AvantMaker.com.
 * For additional code examples and in-depth documentation related to
 * the ESP32 Arduino Core Library, please visit:
 *
 * https://avantmaker.com/home/all-about-esp32-arduino-core-library/
 *
 * AvantMaker.com, your premier destination for all things
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
 * to empowering makers, learners, and enthusiasts with
 * the resources they need to bring their nnovative ideas to life.
 */

#include <WiFi.h>
#include <WebServer.h>

const char* ssid = "your-SSID";          // Replace with your Wi-Fi SSID
const char* password = "your-PASSWORD";  // Replace with your Wi-Fi password

WebServer server(80);

void handleInfo() {
    server.send(200, "text/plain", "AvantMaker.com ESP32 Web Server Demo Page");
}

void setup() {
    Serial.begin(115200);
    WiFi.begin(ssid, password);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("WiFi Connected:");
    Serial.print("Web Server IP: ");
    Serial.println(WiFi.localIP());
    server.on("/", HTTP_GET, handleInfo);
    server.begin();
}

void loop() {
    server.handleClient();
}

/*
 * Author: Avant Maker
 * Date: March 24, 2025
 * Version: 1.0
 * License: MIT 
 * 
 * Description: 
 * This example demonstrates how to use ESP32 WebServer Library's 
 * on() method to implement file uploads to the ESP32's SPIFFS file
 * system:
 *
 * Code Source:
 * This example code is sourced from the Comprehensive Guide
 * to the ESP32 Arduino Core Library, accessible on AvantMaker.com.
 * For additional code examples and in-depth documentation related to
 * the ESP32 Arduino Core Library, please visit:
 *
 * https://avantmaker.com/home/all-about-esp32-arduino-core-library/
 *
 * AvantMaker.com, your premier destination for all things
 * DIY, AI, IoT, Smart Home, and STEM projects. We are dedicated
 * to empowering makers, learners, and enthusiasts with
 * the resources they need to bring their nnovative ideas to life.
 */

#include <WiFi.h>
#include <WebServer.h>
#include <SPIFFS.h>

const char* ssid = "YourWiFiName";
const char* password = "YourWiFiPassword";

WebServer server(80);

File uploadFile;

void setup() {
  Serial.begin(115200);
  
  // Initialize SPIFFS
  if(!SPIFFS.begin(true)){
    Serial.println("An error occurred while mounting SPIFFS");
    return;
  }
  
  // Connect to Wi-Fi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.println("Connecting to WiFi...");
  }
  Serial.println("Connected to WiFi");
  Serial.print("IP address: ");
  Serial.println(WiFi.localIP());
    
  // Route for the root page
  server.on("/", HTTP_GET, []() {
    String html = "<form method='post' action='/upload' enctype='multipart/form-data'>";
    html += "<input type='file' name='upload'>";
    html += "<input type='submit' value='Upload'>";
    html += "</form>";
    server.send(200, "text/html", html);
  });

  // Route to handle file uploads
  server.on("/upload", HTTP_POST, 
    // This is the completion handler (called after upload finishes)
    []() {
      server.send(200, "text/plain", "File uploaded successfully!");
    },
    // This is the upload handler (called during upload)
    handleFileUpload
  );
  
  server.begin();
  Serial.println("HTTP server started");
}

void loop() {
  server.handleClient();
}

void handleFileUpload() {
  HTTPUpload& upload = server.upload();
  
  if (upload.status == UPLOAD_FILE_START) {
    // Start a new upload
    String filename = "/uploads/" + upload.filename;
    Serial.printf("handleFileUpload Name: %s\n", filename.c_str());
    uploadFile = SPIFFS.open(filename, FILE_WRITE);
  } else if (upload.status == UPLOAD_FILE_WRITE) {
    // Write uploaded file data
    if (uploadFile) {
      uploadFile.write(upload.buf, upload.currentSize);
    }
    Serial.printf("handleFileUpload Data: %u\n", upload.currentSize);
  } else if (upload.status == UPLOAD_FILE_END) {
    // End of upload
    if (uploadFile) {
      uploadFile.close();
    }
    Serial.printf("handleFileUpload Size: %u\n", upload.totalSize);
  }
}