Allowed empty constructor, added updateClient() method.

examples/ESP32/CustomKeyboard/InlineKeyboardMarkup/InlineKeyboardMarkup.ino

@@ -27,10 +27,13 @@ void handleNewMessages(int numNewMessages)
     // Inline buttons with callbacks when pressed will raise a callback_query message
     if (bot.messages[i].type == "callback_query")
     {
+      // acknowledge the callback (it will display Thank you text in place of the Loading... toast at top)
+      bot.answerCallbackQuery(bot.messages[i].query_id, "Thank you!", true );
+
       Serial.print("Call back button pressed by: ");
       Serial.println(bot.messages[i].from_id);
       Serial.print("Data on the button: ");
-      Serial.println(bot.messages[i].text);
+      Serial.println(bot.messages[i].text); // 'data' field is saved as 'text' in UTB
       bot.sendMessage(bot.messages[i].from_id, bot.messages[i].text, "");
     }
     else

examples/ESP32/EmptyConstructor/EmptyConstructor.ino

@@ -0,0 +1,81 @@
+/*******************************************************************
+    Based on the echo bot, this one has an EMPTY constructor.
+
+    Useful where you're setting the bot in a task parallel to wifi.
+
+    Adapted by Filipe Laborde from Brian Lough's work
+    Github: https://github.com/mindflowgo
+ *******************************************************************/
+
+#include <WiFi.h>
+#include <WiFiClientSecure.h>
+#include <UniversalTelegramBot.h>
+
+// Wifi network station credentials
+#define WIFI_SSID "YOUR_SSID"
+#define WIFI_PASSWORD "YOUR_PASSWORD"
+// Telegram BOT Token (Get from Botfather)
+#define BOT_TOKEN "XXXXXXXXX:XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX"
+
+const unsigned long BOT_MTBS = 1000; // mean time between scan messages
+
+WiFiClientSecure secured_client;
+UniversalTelegramBot bot; // these are given LATER: (BOT_TOKEN, secured_client);
+unsigned long bot_lasttime; // last time messages' scan has been done
+
+void handleNewMessages(int numNewMessages)
+{
+  for (int i = 0; i < numNewMessages; i++)
+  {
+    bot.sendMessage(bot.messages[i].chat_id, bot.messages[i].text, "");
+  }
+}
+
+void setup()
+{
+  Serial.begin(115200);
+  Serial.println();
+
+  // attempt to connect to Wifi network:
+  Serial.print("Connecting to Wifi SSID ");
+  Serial.print(WIFI_SSID);
+  WiFi.begin(WIFI_SSID, WIFI_PASSWORD);
+  bot.updateClient(secured_client);
+  bot.updateToken(BOT_TOKEN);
+  secured_client.setCACert(TELEGRAM_CERTIFICATE_ROOT); // Add root certificate for api.telegram.org
+  while (WiFi.status() != WL_CONNECTED)
+  {
+    Serial.print(".");
+    delay(500);
+  }
+  Serial.print("\nWiFi connected. IP address: ");
+  Serial.println(WiFi.localIP());
+
+  Serial.print("Retrieving time: ");
+  configTime(0, 0, "pool.ntp.org"); // get UTC time via NTP
+  time_t now = time(nullptr);
+  while (now < 24 * 3600)
+  {
+    Serial.print(".");
+    delay(100);
+    now = time(nullptr);
+  }
+  Serial.println(now);
+}
+
+void loop()
+{
+  if (millis() - bot_lasttime > BOT_MTBS)
+  {
+    int numNewMessages = bot.getUpdates(bot.last_message_received + 1);
+
+    while (numNewMessages)
+    {
+      Serial.println("got response");
+      handleNewMessages(numNewMessages);
+      numNewMessages = bot.getUpdates(bot.last_message_received + 1);
+    }
+
+    bot_lasttime = millis();
+  }
+}

examples/ESP32/EmptyConstructor/README.md

@@ -0,0 +1,11 @@
+#ESP32 - Empty Constructor - configure Client/Token After
+
+In situations where you are setting up wifi parallel to the telegram bot task, you may not have token/client available.
+
+This slight modification built on Brian Lough's excellent telegram bot.
+
+Adapted by [Filipe Laborde](https://github.com/mindflowgo)
+
+## License
+
+You may copy, distribute and modify the software provided that modifications are described and licensed for free under [LGPL-3](http://www.gnu.org/licenses/lgpl-3.0.html). Derivatives works (including modifications or anything statically linked to the library) can only be redistributed under [LGPL-3](http://www.gnu.org/licenses/lgpl-3.0.html), but applications that use the library don't have to be.

src/UniversalTelegramBot.cpp

@@ -43,6 +43,10 @@ UniversalTelegramBot::UniversalTelegramBot(const String& token, Client &client)
   this->client = &client;
 }
 
+void UniversalTelegramBot::updateClient(Client &_client) {
+  client = &_client;
+}
+
 void UniversalTelegramBot::updateToken(const String& token) {
   _token = token;
 }
@@ -66,17 +70,17 @@ String UniversalTelegramBot::sendGetToTelegram(const String& command) {
   String body, headers;
 
   // Connect with api.telegram.org if not already connected
-  if (!client->connected()) {
+  if (client && !client->connected()) {
     #ifdef TELEGRAM_DEBUG  
         Serial.println(F("[BOT]Connecting to server"));
     #endif
-    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
+    if (client && !client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
       #ifdef TELEGRAM_DEBUG  
         Serial.println(F("[BOT]Connection error"));
       #endif
     }
   }
-  if (client->connected()) {
+  if (client && client->connected()) {
 
     #ifdef TELEGRAM_DEBUG  
         Serial.println("sending: " + command);
@@ -104,7 +108,7 @@ bool UniversalTelegramBot::readHTTPAnswer(String &body, String &headers) {
   bool responseReceived = false;
 
   while (millis() - now < longPoll * 1000 + waitForResponse) {
-    while (client->available()) {
+    while (client && client->available()) {
       char c = client->read();
       responseReceived = true;
 
@@ -143,17 +147,17 @@ String UniversalTelegramBot::sendPostToTelegram(const String& command, JsonObjec
   String headers;
 
   // Connect with api.telegram.org if not already connected
-  if (!client->connected()) {
+  if (client && !client->connected()) {
     #ifdef TELEGRAM_DEBUG  
         Serial.println(F("[BOT Client]Connecting to server"));
     #endif
-    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
+    if (client && !client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
       #ifdef TELEGRAM_DEBUG  
         Serial.println(F("[BOT Client]Connection error"));
       #endif
     }
   }
-  if (client->connected()) {
+  if (client && client->connected()) {
     // POST URI
     client->print(F("POST /"));
     client->print(command);
@@ -198,17 +202,17 @@ String UniversalTelegramBot::sendMultipartFormDataToTelegram(
   const String boundary = F("------------------------b8f610217e83e29b");
 
   // Connect with api.telegram.org if not already connected
-  if (!client->connected()) {
+  if (client && !client->connected()) {
     #ifdef TELEGRAM_DEBUG  
         Serial.println(F("[BOT Client]Connecting to server"));
     #endif
-    if (!client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
+    if (client && !client->connect(TELEGRAM_HOST, TELEGRAM_SSL_PORT)) {
       #ifdef TELEGRAM_DEBUG  
         Serial.println(F("[BOT Client]Connection error"));
       #endif
     }
   }
-  if (client->connected()) {
+  if (client && client->connected()) {
     String start_request;
     String end_request;
 
@@ -328,14 +332,14 @@ bool UniversalTelegramBot::setMyCommands(const String& commandArray) {
   payload["commands"] = serialized(commandArray);
   bool sent = false;
   String response = "";
-  #if defined(_debug)
+  #ifdef TELEGRAM_DEBUG  
   Serial.println(F("sendSetMyCommands: SEND Post /setMyCommands"));
-  #endif  // defined(_debug)
+  #endif
   unsigned long sttime = millis();
 
   while (millis() - sttime < 8000ul) { // loop for a while to send the message
     response = sendPostToTelegram(BOT_CMD("setMyCommands"), payload.as<JsonObject>());
-    #ifdef _debug  
+    #ifdef TELEGRAM_DEBUG  
     Serial.println("setMyCommands response" + response);
     #endif
     sent = checkForOkResponse(response);
@@ -357,6 +361,12 @@ int UniversalTelegramBot::getUpdates(long offset) {
   #ifdef TELEGRAM_DEBUG  
     Serial.println(F("GET Update Messages"));
   #endif
+  if( !client ){
+    #ifdef TELEGRAM_DEBUG  
+        Serial.println(F("Sorry invalid client (use updateClient())! Cannot fetch updates!"));
+    #endif
+    return -1; // only time a -1 returned, is when client not set up.
+  }
   String command = BOT_CMD("getUpdates?offset=");
   command += offset;
   command += F("&limit=");
@@ -770,7 +780,7 @@ bool UniversalTelegramBot::sendChatAction(const String& chat_id, const String& t
 }
 
 void UniversalTelegramBot::closeClient() {
-  if (client->connected()) {
+  if (client && client->connected()) {
     #ifdef TELEGRAM_DEBUG  
         Serial.println(F("Closing client"));
     #endif
@@ -809,7 +819,7 @@ bool UniversalTelegramBot::answerCallbackQuery(const String &query_id, const Str
   if (url.length() > 0) payload["url"] = url;
 
   String response = sendPostToTelegram(BOT_CMD("answerCallbackQuery"), payload.as<JsonObject>());
-  #ifdef _debug  
+  #ifdef TELEGRAM_DEBUG  
      Serial.print(F("answerCallbackQuery response:"));
      Serial.println(response);
   #endif

src/UniversalTelegramBot.h

@@ -34,9 +34,6 @@ Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
 #define TELEGRAM_SSL_PORT 443
 #define HANDLE_MESSAGES 1
 
-//unmark following line to enable debug mode
-//#define _debug
-
 typedef bool (*MoreDataAvailable)();
 typedef byte (*GetNextByte)();
 typedef byte* (*GetNextBuffer)();
@@ -68,6 +65,8 @@ struct telegramMessage {
 class UniversalTelegramBot {
 public:
   UniversalTelegramBot(const String& token, Client &client);
+  UniversalTelegramBot() {}; // allows setting token/client later.
+  void updateClient(Client &_client);
   void updateToken(const String& token);
   String getToken();
   String sendGetToTelegram(const String& command);