Telegram bots are automated applications that run inside Telegram. Users can interact with bots by sending messages, commands, and inline requests. Today, we’ll walk you through how to build a simple Telegram bot using Node.js that provides weather and time information for any city.
Prerequisites
Before we start, make sure you have the following:
- Node.js and npm are installed on your machine.
- A Telegram account to create and manage bots.
- An API key from OpenWeatherMap.
Setting Up Your Project
Firstly, install the required Node.js packages: dotenv, node-telegram-bot-api, axios, and moment-timezone.
npm install dotenv node-telegram-bot-api axios moment-timezone
dotenv: To handle environment variables.node-telegram-bot-api: To interact with the Telegram Bot API.axios: To make HTTP requests to the OpenWeatherMap API.moment-timezone: To handle time and time zones.
Creating the Bot
You’ll need a bot token from Telegram. Use the BotFather to create a new bot and get the token. Save the token and your OpenWeatherMap API key in a .env file:
TELEGRAM_BOT_TOKEN=your_telegram_bot_token
OPENWEATHERMAP_API_KEY=your_openweathermap_api_key
In your main JavaScript (app.js) file, initialize your bot and the storage object:
require('dotenv').config();
const TelegramBot = require('node-telegram-bot-api');
const axios = require('axios');
const moment = require('moment-timezone');
const TELEGRAM_BOT_TOKEN = process.env.TELEGRAM_BOT_TOKEN;
const OPENWEATHERMAP_API_KEY = process.env.OPENWEATHERMAP_API_KEY;
const bot = new TelegramBot(TELEGRAM_BOT_TOKEN, { polling: true });
const storage = {};
The storage object will keep track of the state of the conversation with each user.
Handling Commands and Callback Queries
Next, handle the /start command and present the user with two options: getting the weather or the time. We use an inline keyboard for this:
bot.onText(/\/start/, (msg) => {
const chatId = msg.chat.id;
bot.sendMessage(
chatId,
'Hello! This bot can show you the weather and time for any city. To use it, please choose an option below:',
{
reply_markup: {
inline_keyboard: [
[{ text: 'Get Weather', callback_data: 'get_weather' }],
[{ text: 'Get Time', callback_data: 'get_time' }],
],
},
}
);
});
The bot then listens for button presses and asks the user to enter the name of a city:
bot.on('callback_query', async (callbackQuery) => {
const chatId = callbackQuery.message.chat.id;
const data = callbackQuery.data;
switch (data) {
case 'get_weather':
const userDataWeather = getUserData(chatId);
userDataWeather.waitingForCity = true;
userDataWeather.waitingForWeather = true;
bot.sendMessage(chatId, 'Please enter the name of the city or send /stop to cancel:');
break;
case 'get_time':
const userDataTime = getUserData(chatId);
userDataTime.waitingForCity = true;
userDataTime.waitingForTime = true;
bot.sendMessage(chatId, 'Please enter the name of the city or send /stop to cancel:');
break;
default:
break;
}
});
Handling User Responses
The getUserData function initializes or retrieves the user’s state from the storage object:
function getUserData(chatId) {
let userData = storage[chatId];
if (!userData) {
userData = {
waitingForCity: false,
waitingForWeather: false,
waitingForTime: false,
};
storage[chatId] = userData;
}
return userData;
}
Then, the bot listens for a message from the user, which should be the city’s name:
bot.on('message', async (msg) => {
const chatId = msg.chat.id;
const text = msg.text;
const userData = getUserData(chatId);
if (userData && userData.waitingForCity) {
const city = text;
let messageText = '';
if (userData.waitingForWeather) {
messageText = await getWeatherData(city);
} else if (userData.waitingForTime) {
messageText = await getTimeData(city);
}
bot.sendMessage(chatId, messageText);
resetUserData(chatId);
}
});
We reset the user data after sending the response so the bot is ready for the next command. The resetUserData function looks like this:
function resetUserData(chatId) {
const userData = getUserData(chatId);
userData.waitingForCity = false;
userData.waitingForWeather = false;
userData.waitingForTime = false;
}
Fetching the Weather and Time Data
The getWeatherData function fetches weather data from the OpenWeatherMap API:
async function getWeatherData(city) {
const response = await axios.get(
`http://api.openweathermap.org/data/2.5/weather?q=${city}&appid=${OPENWEATHERMAP_API_KEY}`
);
const weatherData = response.data;
const weatherDescription = weatherData.weather[0].description;
const temperature = Math.round(weatherData.main.temp - 273.15);
const messageText = `The weather in ${city} is currently ${weatherDescription} with a temperature of ${temperature}°C.`;
return messageText;
}
The getTimeData function gets the current time in the city’s local timezone using moment-timezone:
async function getTimeData(city) {
const response = await axios.get(
`http://api.geonames.org/timezoneJSON?formatted=true&lat=${city.lat}&lng=${city.lon}&username=demo&style=full`
);
const data = response.data;
const localTime = data.time;
const messageText = `The current time in ${city} is ${localTime}.`;
return messageText;
}
Running The Bot
Update your package.json file to run the bot:
"scripts": {
"start": "node app.js"
}
Run the command on a terminal:
npm start
Open your Bot on the Telegram app to test it:
Wrapping Up
This simple bot is a fun way to explore the capabilities of Telegram bots and Node.js. The bot could be expanded in numerous ways, such as supporting more commands, integrating more APIs, or adding a more sophisticated conversation state.
Remember to secure your API keys and tokens properly. Never expose them in your code or version control system. Instead, use environment variables or some form of secure secret management.
Happy coding!