Merge pull request me-no-dev#36 from ESP32Async/example/fetch

Added fetch website example

Author: mathieucarbou

.github/workflows/ci.yml

@@ -28,13 +28,18 @@ jobs:
           arduino-cli --config-file ${{ matrix.config }} core update-index
           arduino-cli --config-file ${{ matrix.config }} board listall
           arduino-cli --config-file ${{ matrix.config }} core install esp32:esp32
-      - name: Compile Sketch
+
+      - name: Client
         run: arduino-cli --config-file ${{ matrix.config }} --library ./src/ compile --fqbn esp32:esp32:esp32 ./examples/Client/Client.ino
-      - name: Compile Sketch with IPv6
+
+      - name: Client IPv6
         env:
           LWIP_IPV6: true
         run: arduino-cli --config-file ${{ matrix.config }} --library ./src/ compile --fqbn esp32:esp32:esp32 ./examples/Client/Client.ino
 
+      - name: FetchWebsite
+        run: arduino-cli --config-file ${{ matrix.config }} --library ./src/ compile --fqbn esp32:esp32:esp32 ./examples/FetchWebsite/FetchWebsite.ino
+
   platformio:
     name: "pio:${{ matrix.env }}:${{ matrix.board }}"
     runs-on: ubuntu-latest
@@ -85,3 +90,4 @@ jobs:
           pip install --upgrade platformio
 
       - run: PLATFORMIO_SRC_DIR=examples/Client PIO_BOARD=${{ matrix.board }} pio run -e ${{ matrix.env }}
+      - run: PLATFORMIO_SRC_DIR=examples/FetchWebsite PIO_BOARD=${{ matrix.board }} pio run -e ${{ matrix.env }}

examples/FetchWebsite/FetchWebsite.ino

@@ -0,0 +1,111 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+// Copyright 2016-2025 Hristo Gochkov, Mathieu Carbou, Emil Muratov
+
+#include <Arduino.h>
+#include <AsyncTCP.h>
+#include <StreamString.h>
+#include <WiFi.h>
+
+#include <functional>
+#include <string>
+
+#define WIFI_SSID     "IoT"
+#define WIFI_PASSWORD ""
+
+void fetchAsync(const char *host, std::function<void(const StreamString *)> onDone) {
+  Serial.printf("[%s] Fetching: http://%s...\n", host, host);
+
+  // buffer where we will accumulate the received data
+  StreamString *content = new StreamString();
+
+  // reserve enough space to avoid reallocations
+  content->reserve(32 * 1024);
+
+  // create a new client
+  AsyncClient *client = new AsyncClient();
+
+  // register a callback when the client disconnects
+  client->onDisconnect([content, host, onDone](void *arg, AsyncClient *client) {
+    Serial.printf("[%s] Disconnected.\n", host);
+    onDone(content);
+    delete client;
+    delete content;
+  });
+
+  // register a callback when an error occurs
+  client->onError([host, onDone](void *arg, AsyncClient *client, int8_t error) {
+    Serial.printf("[%s] Error: %s\n", host, client->errorToString(error));
+  });
+
+  // register a callback when data arrives, to accumulate it
+  client->onData([host, content](void *arg, AsyncClient *client, void *data, size_t len) {
+    Serial.printf("[%s] Received %u bytes...\n", host, len);
+    content->write((const uint8_t *)data, len);
+  });
+
+  // register a callback when we are connected
+  client->onConnect([host](void *arg, AsyncClient *client) {
+    Serial.printf("[%s] Connected!\n", host);
+
+    // send request
+    client->write("GET / HTTP/1.1\r\n");
+    client->write("Host: ");
+    client->write(host);
+    client->write("\r\n");
+    client->write("User-Agent: ESP32\r\n");
+    client->write("Connection: close\r\n");
+    client->write("\r\n");
+  });
+
+  Serial.printf("[%s] Connecting...\n", host);
+
+  client->setRxTimeout(20000);
+  // client->setAckTimeout(10000);
+  client->setNoDelay(true);
+
+  if (!client->connect(host, 80)) {
+    Serial.printf("[%s] Failed to connect!\n", host);
+    delete client;
+    delete content;
+    onDone(nullptr);
+  }
+}
+
+void setup() {
+  Serial.begin(115200);
+  while (!Serial) {
+    continue;
+  }
+
+  // connect to WiFi
+  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+  while (WiFi.status() != WL_CONNECTED) {
+    delay(500);
+  }
+  Serial.println("Connected to WiFi!");
+  Serial.println(WiFi.localIP());
+
+  // fetch asynchronously 2 websites:
+
+  // equivalent to curl -v --raw http://www.google.com/
+  fetchAsync("www.google.com", [](const StreamString *content) {
+    if (content) {
+      Serial.printf("[www.google.com] Fetched website:\n%s\n", content->c_str());
+    } else {
+      Serial.println("[www.google.com] Failed to fetch website!");
+    }
+  });
+
+  // equivalent to curl -v --raw http://www.time.org/
+  fetchAsync("www.time.org", [](const StreamString *content) {
+    if (content) {
+      Serial.printf("[www.time.org] Fetched website:\n%s\n", content->c_str());
+    } else {
+      Serial.println("[www.time.org] Failed to fetch website!");
+    }
+  });
+}
+
+void loop() {
+  delay(500);
+}

platformio.ini

@@ -1,7 +1,8 @@
 [platformio]
 default_envs = arduino-2, arduino-3
 lib_dir = .
-src_dir = examples/Client
+; src_dir = examples/Client
+src_dir = examples/FetchWebsite
 
 [env]
 framework = arduino