[examples] Update examples

Feature:

  * Add example demonstrating use of inline keyboards
    and callback queries (see PR #150)
  * Use token from environment variable, if available

References:

  * PR #150 - Provided example with inline keyboard and callbacks:
    https://github.com/yagop/node-telegram-bot-api/pull/150

examples/httpsWebHook.js

@@ -4,7 +4,7 @@
  */
 
 
-const TOKEN = 'YOUR_TELEGRAM_BOT_TOKEN';
+const TOKEN = process.env.TELEGRAM_TOKEN || 'YOUR_TELEGRAM_BOT_TOKEN';
 const TelegramBot = require('..');
 const options = {
   webHook: {

examples/openShiftWebHook.js

@@ -4,7 +4,7 @@
  */
 
 
-const TOKEN = 'YOUR_TELEGRAM_BOT_TOKEN';
+const TOKEN = process.env.TELEGRAM_TOKEN || 'YOUR_TELEGRAM_BOT_TOKEN';
 const TelegramBot = require('..');
 // See https://developers.openshift.com/en/node-js-environment-variables.html
 const options = {

examples/polling.js

@@ -4,7 +4,7 @@
  */
 
 
-const TOKEN = 'YOUR_TELEGRAM_BOT_TOKEN';
+const TOKEN = process.env.TELEGRAM_TOKEN || 'YOUR_TELEGRAM_BOT_TOKEN';
 const TelegramBot = require('..');
 const request = require('request');
 const options = {
@@ -52,3 +52,41 @@ bot.onText(/\/echo (.+)/, function onEchoText(msg, match) {
   const resp = match[1];
   bot.sendMessage(msg.chat.id, resp);
 });
+
+
+// Matches /editable
+bot.onText(/\/editable/, function onEditableText(msg) {
+  const opts = {
+    reply_markup: {
+      inline_keyboard: [
+        [
+          {
+            text: 'Edit Text',
+             // we shall check for this value when we listen
+             // for "callback_query"
+            callback_data: 'edit'
+          }
+        ]
+      ]
+    }
+  };
+  bot.sendMessage(msg.from.id, 'Original Text', opts);
+});
+
+
+// Handle callback queries
+bot.on('callback_query', function onCallbackQuery(callbackQuery) {
+  const action = callbackQuery.data;
+  const msg = callbackQuery.message;
+  const opts = {
+    chat_id: msg.chat.id,
+    message_id: msg.message_id,
+  };
+  let text;
+
+  if (action === 'edit') {
+    text = 'Edited Text';
+  }
+
+  bot.editMessageText(text, opts);
+});