Discord Bot Programming From Basic To Advanced With Node.js

Discord has become a popular communication platform not only for gamers but also for communities, organizations, and individuals. To enhance the experience and automate tasks, creating a Discord bot is a great choice. This article will guide you through programming a Discord bot from basic to advanced using Node.js, a powerful and popular JavaScript programming language.

1. Why Program a Discord Bot with Node.js?

Node.js is a great choice for developing a Discord bot for the following reasons:

• Popular JavaScript: JavaScript is one of the most popular programming languages ​​in the world, with a large community and a lot of supporting documentation.

• High Performance: Node.js uses asynchronous architecture (non-blocking I/O), helping your bot handle multiple requests simultaneously without any delay.

• Easy to Learn: If you already have some knowledge of JavaScript, learning Node.js will be quite easy.

• Lots of Supported Libraries: There are many powerful and easy-to-use libraries specifically for developing Discord bots with Node.js, the most prominent one is discord.js.

• Large Community: The Node.js and Discord communities are large and active, you will easily find support if you run into problems.

2. Preparation Steps Before Starting

Before starting to write code, you need to prepare some things:

2.1 Install Node.js and npm

Node.js installation guide for beginners

• Visit the official Node.js website (nodejs.org) to download and install the latest stable version for your operating system.

• npm (Node Package Manager) will be installed automatically along with Node.js. npm is a tool to manage JavaScript library packages.

2.2 Create a Discord Application

• Go to the Discord Developer Portal (discord.com/developers/applications).

• Log in to your Discord account.

• Click the “New Application” button and name your bot.

• After creating your application, you will see information about your application.

2.3 Create a Bot

• In your application page, select “Bot” in the left menu bar.

• Click the “Add Bot” button.

• Confirm the creation of the bot.

• Note: You will see a “Token” of the bot. This is an extremely important and confidential information. Do not share this token with anyone.

2.4 Inviting the Bot to the Discord Server

• In your app page, select “OAuth2” in the left menu bar.

• In the “Scopes” section, select “bot”.

• In the “Bot Permissions” section, select the permissions your bot needs (e.g. send messages, read messages, manage messages, etc.). Choose the permissions that match the bot’s functionality.

• Copy the link generated in the “Generated URL” section.

• Open this link in your browser and select the Discord server you want to invite the bot to.

3. Getting Started with Basic Discord Bot Programming

Now, we’ll start coding a basic Discord bot.

3.1. Creating a Project Folder

• Create a new folder on your computer for your bot project (e.g. my-discord-bot).

• Open a terminal or command prompt and navigate to this directory.

3.2. Initialize Node.js Project

• Run the following command in the terminal:

npm init -y

This command will create a basic package.json file for your project.

3.3. Install the discord.js Library

Install Discord Library

• Run the following command to install the discord.js library:

npm install discord.js

3.4. Create index.js File

• Create a new file in your project folder and name it index.js. This will be the main file containing the bot’s code.

3.5. Writing Basic Bot Code

• Open the index.js file and add the following code:

// Import the discord.js library
const { Client, GatewayIntentBits } = require('discord.js');

// Create an instance of Client
const client = new Client({ intents: [GatewayIntentBits.Guilds, GatewayIntentBits.GuildMessages, GatewayIntentBits.MessageContent] });

// Replace 'YOUR_BOT_TOKEN' with your bot token
const token = 'YOUR_BOT_TOKEN';

// Event when the bot is ready
client.on('ready', () => {
console.log(`Logged in as ${client.user.tag}!`);
});

// New message event
client.on('messageCreate', msg => {
if (msg.author.bot) return; // Ignore messages from bot

if (msg.content === '!hello') {
msg.reply('Hello!');
}
});

// Log in to Discord with bot token
client.login(token);

• Code explanation:

• require('discord.js'): Import the discord.js library.

• const { Client, GatewayIntentBits } = require('discord.js');: Declare the necessary classes from discord.js.

• const client = new Client(...): Create a Client object, this is the starting point for interacting with the Discord API. intents define the events your bot will receive. Guilds, GuildMessages, and MessageContent are common intents.

• const token = 'YOUR_BOT_TOKEN';: Stores your bot’s token (replace 'YOUR_BOT_TOKEN' with the actual token).

• client.on('ready', ...): This event is fired when the bot has successfully logged into Discord.

• client.on('messageCreate', ...): This event is fired when a new message is sent on the server the bot is on.

• if (msg.author.bot) return;: Checks if the message is from another bot. If so, ignore it.

• if (msg.content === '!hello') { ... }: Checks if the message content is !hello. If so, the bot will send a reply message “Hello!”.

• client.login(token);: Logs the bot into Discord using the provided token.

3.6. Running the Bot

• Open a terminal or command prompt in your project folder.

• Run the following command to start the bot:

node index.js

• If everything went well, you should see a “Logged in as [BotName]!” message in the terminal.

3.7. Testing the Bot in Discord

• Open Discord and go to the server you invited the bot to.

• Send a !hello message in a text channel.

Your bot should reply “Hello!”.

4. Discord Bot Upgrades: Advanced Features

Once we have a basic bot, we can add more advanced features.

4.1. Commands

• Instead of checking each message one by one, you can use a structure to handle specific commands.

// ... (import and initialize client) ...

const prefix = '!'; // Command prefix

 client.on('messageCreate', msg => {
 if (!msg.content.startsWith(prefix) || msg.author.bot) return;

 const args = msg.content.slice(prefix.length).trim().split(/ +/);
 const command = args.shift().toLowerCase();

 if (command === 'ping') {
 msg.reply(`Pong! Delay: ${Date.now() - msg.createdTimestamp}ms`);
 } else if (command === 'say') {
 if (args.length > 0) {
 msg.channel.send(args.join(' '));
 } else {
 msg.reply('Please enter content for the bot to speak.');
 }
 }
 });

 // ... (login section) ...

• Explanation:
• prefix: Defines a prefix for commands (e.g. !).
• if (!msg.content.startsWith(prefix) || msg.author.bot) return;: Checks if the message starts with the prefix and is not from another bot.
• msg.content.slice(prefix.length).trim().split(/ +/): Splits the message content into arguments.
• command: Gets the command name (the first part after the prefix).
• if (command === '...') blocks handle specific commands (ping, say).

4.2. Using Embeds

• Embeds are beautifully formatted messages with titles, descriptions, colors, images, etc.

const { EmbedBuilder } = require('discord.js');

// ... (client part) ...

client.on('messageCreate', msg => {
// ... (command handling) ...

if (command === 'info') {
const infoEmbed = new EmbedBuilder()
.setColor('#0099ff')
.setTitle('Bot Info')
.setDescription('This is a simple Discord bot written in Node.js.')
.addFields(
{ name: 'Author', value: 'Your Name' },
{ name: 'Version', value: '1.0.0' },
)
.setTimestamp();

msg.channel.send({ embeds: [infoEmbed] });
}
});

// ... (login section) ...

• Explanation:

• const { EmbedBuilder } = require('discord.js');: Import EmbedBuilder.

• const infoEmbed = new EmbedBuilder(): Create an embed object.

• .setColor(), .setTitle(), .setDescription(), .addFields(), .setTimestamp(): Methods to set embed properties.

• msg.channel.send({ embeds: [infoEmbed] });: Send embed to channel.

4.3. Interacting with External APIs

• Your bot can interact with external APIs to get information (e.g. weather, news, game information, etc.). You can use the node-fetch or axios libraries to perform HTTP requests.

const fetch = require('node-fetch'); // npm install node-fetch

// ... (client part) ...

client.on('messageCreate', async msg => {
// ... (command execution) ...

if (command === 'weather') {
const city = args.join(' ');
if (!city) {
return msg.reply('Please enter a city name.');
}

const apiKey = 'YOUR_OPENWEATHERMAP_API_KEY'; // Replace with your API key
const apiUrl = `https://api.openweathermap.org/data/2.5/weather?q=${city}&appid=${apiKey}&units=metric`;

try {
const response = await fetch(apiUrl);
const data = await response.json();

if (data.cod === '404') {
return msg.reply('City not found.');
}

const weatherEmbed = new EmbedBuilder()
.setColor('#00ccff')
.setTitle(`Weather at ${data.name}`)
.setDescription(`${data.weather[0].description}`)
.addFields(
{ name: 'Temperature', value: `${data.main.temp}°C`, inline: true },
{ name: 'Humidity', value: `${data.main.humidity}%`, inline: true },
{ name: 'Wind speed', value: `${data.wind.speed} m/s`, inline: true },
)
.setTimestamp();

msg.channel.send({ embeds: [weatherEmbed] });

} catch (error) {
console.error('Error calling API:', error);
msg.reply('An error occurred while retrieving weather information.');
}
}
});

// ... (login section) ...

• Explanation:

• require('node-fetch'): Imports the node-fetch library.

• async/await: Used to handle asynchronous requests in a readable way.

• Call the OpenWeatherMap API to get weather data.

Display weather information in an embed.

4.4. Data Management

• Your bot may need to store data (e.g. server settings, user information). You can use different methods to manage data, including:

• JSON files: Simple but not efficient for large data.

• Database: Examples: MongoDB, PostgreSQL, MySQL.

// Example using a simple JSON file
const fs = require('node:fs/promises');
const configFilePath = './config.json';
let config = {};

async function loadConfig() {
try {
const data = await fs.readFile(configFilePath, 'utf8');
config = JSON.parse(data);
} catch (error) {
console.log('Configuration file not found, create new one.');
config = { prefix: '!' };
await fs.writeFile(configFilePath, JSON.stringify(config, null, 2), 'utf8');
}
}

async function saveConfig() {
await fs.writeFile(configFilePath, JSON.stringify(config, null, 2), 'utf8');
}

// ... (in ready event) ...
client.on('ready', async () => {
await loadConfig();
console.log(`Logged in as ${client.user.tag}! Current prefix: ${config.prefix}`);
});

client.on('messageCreate', async msg => {
if (!msg.content.startsWith(config.prefix) || msg.author.bot) return;
// ... (process the command using config.prefix) ...
});

// ... (in the command to change the prefix) ...
if (command === 'setprefix') {
if (args.length !== 1) {
return msg.reply(`Usage: ${config.prefix}setprefix <new_prefix>`);
}
config.prefix = args[0];
await saveConfig();
msg.reply(`Prefix set to \`${config.prefix}\``);
}

// ... (login section) ...

• Explanation:

• Use the fs/promises module to read and write JSON files.

• loadConfig(): Loads the configuration from a file or creates a new one if it doesn’t exist.

• saveConfig(): Saves the configuration to a file.

Example of the setprefix command to change the prefix.

4.5. Using Advanced Events

• Discord.js provides many other events that you can listen for, such as guildMemberAdd, guildMemberRemove, messageReactionAdd, voiceStateUpdate, etc.

client.on('guildMemberAdd', member => {
const welcomeChannelId = 'WELCOME_CHANNEL_ID'; // Replace with actual welcome channel ID
const welcomeChannel = member.guild.channels.cache.get(welcomeChannelId);
if (welcomeChannel) {
welcomeChannel.send(`Welcome ${member} to the server!`);
}
});

client.on('messageReactionAdd', (reaction, user) => {
if (reaction.message.id === 'SPECIFIC_MESSAGE_ID' && reaction.emoji.name === '👍') {
// Perform action when user reacts 👍 to specific message
console.log(`${user.tag} reacted 👍 to message.`);
}
});

• Explanation:
• client.on('guildMemberAdd', ...): Event when a new member joins the server.
• client.on('messageReactionAdd', ...): Event when an emoji reaction is added to a

6. Conclusion

Programming a Discord bot is not only a great way to automate tasks and enhance the Discord experience, but also an opportunity for you to learn and develop your programming skills. The Discord community and the Node.js community are always ready to support you on this path.

Don’t hesitate to experiment, explore and be creative. Start with simple bots, then gradually expand and integrate more complex features. With perseverance and passion, you can absolutely create impressive Discord bots, meet the needs of the community and bring a lot of value.

If you have any questions, please contact us via Email or Telegram.

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