Creating a Play Command

In this guide, we will learn how to create a play command using Discord Player. The play command allows users to play music in a voice channel.

Prerequisites

Before creating a play command, make sure you have ffmpeg installed on your system. Discord Player uses ffmpeg to transcode audio streams. You may also install ffmpeg from npm, although it is not recommended due to its unstable nature.

npm install --save ffmpeg-static
# or
npm install --save @ffmpeg-installer/ffmpeg
# or
npm install --save @node-ffmpeg/node-ffmpeg-installer
# or
npm install --save ffmpeg-binaries

Design Planning

Before we dive into the code, let's plan the design of our play command:

Command Definition: We will define a new slash command named play using SlashCommandBuilder.
Option Handling: The command will have a required option named song to specify the song to play.
Player Instance: We will use the useMainPlayer hook to get the player instance.
Permission Checks: We will check if the user is in a voice channel and if the bot has the necessary permissions.
Playing: We will play the requested song in the user's voice channel.
Response: We will send a confirmation message indicating the song has been added to the queue.

Step 1: Define the Command

First, we need to define the play command using SlashCommandBuilder.

play.js

// Import necessary classes from discord.js
import { SlashCommandBuilder } from 'discord.js';
 
// Define the play command
export const data = new SlashCommandBuilder()
  .setName('play') // Command name
  .setDescription('Play a song in a voice channel') // Command description
  .addStringOption(
    (option) =>
      option
        .setName('song') // Option name
        .setDescription('The song to play') // Option description
        .setRequired(true), // Make the option required
  );

Step 2: Get the Player Instance and Song Query

Next, we need to get the player instance and the song query from the user.

play.js

// Import the useMainPlayer function from discord-player
import { useMainPlayer } from 'discord-player';
 
// Define the execute function for the play command
export async function execute(interaction) {
  // Get the player instance
  const player = useMainPlayer();
  // Get the song query from the user input
  const query = interaction.options.getString('song', true);
}

Step 3: Check User and Bot Permissions

We need to check if the user is in a voice channel and if the bot has the necessary permissions.

play.js

// Import necessary classes from discord.js
import { PermissionsBitField } from 'discord.js';
 
// Define the execute function for the play command
export async function execute(interaction) {
  // Get the player instance and song query
  const player = useMainPlayer();
  const query = interaction.options.getString('song', true);
 
  // Get the voice channel of the user
  const voiceChannel = interaction.member.voice.channel;
 
  // Check if the user is in a voice channel
  if (!voiceChannel) {
    return interaction.reply('You need to be in a voice channel to play music!');
  }
 
  // Check if the bot is already playing in a different voice channel
  if (interaction.guild.members.me.voice.channel && interaction.guild.members.me.voice.channel !== voiceChannel) {
    return interaction.reply('I am already playing in a different voice channel!');
  }
 
  // Check if the bot has permission to join the voice channel
  if (!interaction.guild.members.me.permissions.has(PermissionsBitField.Flags.Connect)) {
    return interaction.reply('I do not have permission to join your voice channel!');
  }
 
  // Check if the bot has permission to speak in the voice channel
  if (!interaction.guild.members.me.permissionsIn(voiceChannel).has(PermissionsBitField.Flags.Speak)) {
    return interaction.reply('I do not have permission to speak in your voice channel!');
  }
}

Step 4: Play the Song

Finally, we need to play the song and handle any errors that may occur.

play.js

// Define the execute function for the play command
export async function execute(interaction) {
  // Get the player instance and song query
  const player = useMainPlayer();
  const query = interaction.options.getString('song', true);
 
  // Get the voice channel of the user and check permissions
  const voiceChannel = interaction.member.voice.channel;
 
  if (!voiceChannel) {
    return interaction.reply('You need to be in a voice channel to play music!');
  }
 
  if (interaction.guild.members.me.voice.channel && interaction.guild.members.me.voice.channel !== voiceChannel) {
    return interaction.reply('I am already playing in a different voice channel!');
  }
 
  if (!voiceChannel.permissionsFor(interaction.guild.members.me).has(PermissionsBitField.Flags.Connect)) {
    return interaction.reply('I do not have permission to join your voice channel!');
  }
 
  if (!voiceChannel.permissionsFor(interaction.guild.members.me).has(PermissionsBitField.Flags.Speak)) {
    return interaction.reply('I do not have permission to speak in your voice channel!');
  }
 
  try {
    // Play the song in the voice channel
    const result = await player.play(voiceChannel, query, {
      nodeOptions: {
        metadata: { channel: interaction.channel }, // Store text channel as metadata on the queue
      },
    });
 
    // Reply to the user that the song has been added to the queue
    return interaction.reply(`${result.track.title} has been added to the queue!`);
  } catch (error) {
    // Handle any errors that occur
    console.error(error);
    return interaction.reply('An error occurred while playing the song!');
  }
}

Handling Track Lifecycle Events

You can also handle track lifecycle events to send messages when a track starts or finishes playing.

index.js

// Import necessary classes from discord-player
import { GuildQueueEvent } from 'discord-player';
 
// Handle the event when a track starts playing
player.events.on(GuildQueueEvent.PlayerStart, async (queue, track) => {
  // Get the metadata stored on the queue
  const { channel } = queue.metadata;
  // Send a message to the channel
  await channel.send(`Now playing: ${track.title}`);
});
 
// Handle the event when a track finishes playing
player.events.on(GuildQueueEvent.PlayerFinish, async (queue, track) => {
  // Get the metadata stored on the queue
  const { channel } = queue.metadata;
  // Send a message to the channel
  await channel.send(`Finished playing ${track.title}`);
});

That's it! You have successfully created a play command using Discord Player. You can now play music in your Discord bot.

Creating a Play Command

Prerequisites

Design Planning

Step 1: Define the Command

Step 2: Get the Player Instance and Song Query

Step 3: Check User and Bot Permissions

Step 4: Play the Song

Handling Track Lifecycle Events

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