Let’s Start Bot Development with Discord.js! ~ From Basics to Applications and Community ~

Discord.js, the standard library for Discord bot development.

Written in JavaScript, it is supported by a wide range of developers from beginners to advanced users.

In this article, we will explain in detail bot development using Discord.js, from the basics to applications, and community information.

What is Discord.js?

Discord.js is a powerful Node.js module for easily manipulating the Discord API.

It has a rich set of features necessary for bot development, such as sending and receiving messages, adding reactions, joining voice channels, and creating Embed messages.

Why Discord.js is Chosen

Object-Oriented: Easy code structuring improves maintainability and readability.
JavaScript: Because it is a widely used language, there are many learning resources.
Active Community: Supported by many developers, there is an active community.
Rich Documentation: Rich official documentation and guides are useful for learning.

Advantages of Discord.js

Easy to Handle for Beginners: Because the code is organized in an object-oriented way, it is easy for beginners to understand.
Abundant Information: A lot of information is available from official documentation, guides, and communities, making it easy to learn.
Easy to Set Up a Development Environment: You can start developing with JavaScript and Node.js, making environment construction easy.

Resources for Learning Discord.js

Official Documentation: [Discord.js Documentation]([無効な URL を削除しました]
Official Guide: discord.js guide
Discord.js Japan User Group: Discord.js Japan User Group
Introductory Articles: なるべく初心者にわかりやすいdiscord.js入門
Other: GeekLibrary, Qiita, Zenn etc.

Differences Between Discord.js v14 and v15

Discord.js changed the WebSocket library from ws to @discordjs/ws in v14. Also, support for GuildMember#flags was added.

v15 seems to be a stable release based on v14. Although detailed information is limited, you can check new features and changes from the release notes.

How to Use Discord.js

The basic steps for bot development using Discord.js are as follows:

Environment Setup: Install Node.js and npm.
Create Project: Create a folder for the project and initialize it with the npm init -y command.
Install Discord.js: Install Discord.js with the npm install discord.js command.
Create Bot Account: Create a bot account on the Discord Developer Portal and get a token.
Write Code: Write code in JavaScript to describe the behavior of the bot.

Code Example

      const { Client, Intents } = require('discord.js');
const client = new Client({ intents: [Intents.FLAGS.GUILDS, Intents.FLAGS.GUILD_MESSAGES] });

client.on('ready', () => {
  console.log(`Logged in as ${client.user.tag}!`);
});

client.on('messageCreate', msg => {
  if (msg.content === 'ping') {
    msg.reply('Pong!');
  }
});

client.login('your-token-here');

content_copy download Use code with caution.JavaScript

In this code, a bot is created that replies with “Pong!” when the message content is “ping”.

Run the Bot: Run the created code and have the bot operate on Discord.

Utilizing Embed Messages

By using Embed messages, you can improve visibility compared to regular messages.

Slash Commands

Slash commands are commands that start with / and are a modern way to interact with Discord bots. In Discord.js v15, you can easily create slash commands using SlashCommandBuilder.

Implementation of Slash Commands

Define a command using SlashCommandBuilder.
Register the command with Discord.
Handle command execution in the interactionCreate event.

Buttons

Buttons are interactive elements that users can use to interact with the bot. In Discord.js, you can create buttons and attach them to messages.

Types of Buttons

PRIMARY (Blue)
SECONDARY (Gray)
SUCCESS (Green)
DANGER (Red)
LINK (Link)

Button Functionality

Changing the style of buttons
Creating link buttons
Disabling buttons
Creating emoji buttons

Threads

Threads are a feature for organizing conversations on specific topics. In Discord.js, you can perform various operations related to threads, such as creating threads, adding/removing members, and sending messages.

Thread Operations

Creating threads
Adding and removing members
Sending messages

Sending Messages using Webhooks

Error Handling

When developing bots with Discord.js, errors may occur. There are errors that originate from the Discord.js library itself and errors that originate from the Discord API.

Common Errors and Solutions

CLIENT_MISSING_INTENTS: This error occurs when Gateway Intents are not set correctly. You need to set Gateway Intents correctly to control the events the bot receives.
node-gyp errors: An error that may occur during Discord.js installation. It can sometimes be resolved by installing the required tools or executing the command with administrator privileges.
SyntaxError: Unexpected Token: An error that occurs when there is an error in the code syntax. You need to check the error message and correct the code syntax.
TypeError: Cannot read properties of undefined: An error that occurs when you try to access a property of an object, but the object is undefined. You need to make sure the object is correctly defined.

How to Participate in the Discord Bot Development Community

To join the official Discord.js community, please follow these steps:

Visit the website of the Discord.js Japan User Group ([Discord.js Japan User Group]([無効な URL を削除しました]).
Click the invite link to the Discord server listed on the website.
Join the Discord server and interact with other developers.

Conclusion

In this article, we have explained in detail how to create a bot using Discord.js, from the basics to applications, and community information.

Discord.js is an easy-to-use library for beginners, and many resources are available. Please refer to the official documentation and guides and try your hand at Discord bot development.

By using Discord.js, you can organize code in an object-oriented manner and improve maintainability and readability. You can also take advantage of the abundant JavaScript learning resources and receive support from the active community.

So, why not create your own original bot using Discord.js?