discord-scene

A simple library to implement multi-step conversations ("scenes") and session storage in a Discord bot, inspired by Telegraf Scenes.

Features

• Scene-based workflow: Define multiple scenes, each with onEnter, onLeave, and onMessage callbacks.
• Session storage: Store and retrieve data for each user. By default, it's in-memory, but you can easily extend it to Redis or a database.
• Stage manager: A central Stage that keeps track of user states (which scene they're in, their session data, etc.) and handles transitions between scenes.

Installation

npm install discord-scene

Below is a minimal example of how to set up a Discord bot using discord-scene. In this scenario, the bot will walk the user through collecting their name and age.

// index.js
const { Client, GatewayIntentBits } = require('discord.js');
const {
  Stage,
  Scene,
  MemorySessionStore,
} = require('discord-scene');

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

// 1) Create a session store and a Stage
const sessionStore = new MemorySessionStore();
const stage = new Stage(sessionStore);

// 2) Define a scene
const userInfoScene = new Scene('userInfoScene');

// Called when the user enters the scene
userInfoScene.onEnter(async (ctx) => {
  ctx.sessionData.step = 1;
  await ctx.message.reply('Hello! What is your name?');
});

// Called when the user leaves the scene
userInfoScene.onLeave(async (ctx) => {
  await ctx.message.reply('Leaving the scene. Have a nice day!');
});

// Called for each message while in this scene
userInfoScene.onMessage(async (ctx) => {
  const step = ctx.sessionData.step;

  if (step === 1) {
    ctx.sessionData.name = ctx.message.content.trim();
    ctx.sessionData.step = 2;
    await ctx.message.reply(`Nice to meet you, ${ctx.sessionData.name}! How old are you?`);
    return;
  }

  if (step === 2) {
    const ageNum = parseInt(ctx.message.content.trim(), 10);
    if (isNaN(ageNum)) {
      await ctx.message.reply('Please enter a valid number for your age.');
      return;
    }
    ctx.sessionData.age = ageNum;
    ctx.sessionData.step = 3;
    await ctx.message.reply(
      `So, your name is ${ctx.sessionData.name}, and you are ${ctx.sessionData.age} years old. Is that correct? (yes/no)`
    );
    return;
  }

  if (step === 3) {
    const answer = ctx.message.content.toLowerCase();
    if (answer === 'yes') {
      await ctx.message.reply('Great! Your data has been recorded. Thanks!');
      // Exit the scene
      await stage.enter(null, ctx);
    } else if (answer === 'no') {
      await ctx.message.reply('Let’s start over. Type `!start` again if you want to retry.');
      // Exit the scene
      await stage.enter(null, ctx);
    } else {
      await ctx.message.reply('Please answer "yes" or "no".');
    }
  }
});

// 3) Register the scene
stage.register(userInfoScene);

// 4) Handle Discord messages
client.on('messageCreate', async (message) => {
  if (message.author.bot) return;

  const ctx = {
    message,
    userId: message.author.id,
  };

  // Command to start the scene
  if (message.content === '!start') {
    await stage.enter('userInfoScene', ctx);
    return;
  }

  // Otherwise, let the stage handle the message
  await stage.handleMessage(ctx);
});

client.once('ready', () => {
  console.log(`Bot is ready as ${client.user.tag}`);
});

client.login('YOUR_BOT_TOKEN');

1. Replace YOUR_BOT_TOKEN with your real token from the Discord Developer Portal.

2. Run the bot: bash node index.js

3. Invite your bot to a server and type !start. You will be guided through a multi-step conversation.

API Reference

MemorySessionStore

• getSession(userId): Returns the user's session object or null if none exists.
• setSession(userId, sessionData): Saves or updates the session data.
• deleteSession(userId): Removes the session data for the user.

class Stage

Orchestrates scene management and user state.

• Constructor:

const stage = new Stage(sessionStore);

Accepts an instance of a SessionStore.

• register(...scenes): Register one or more Scene objects.
• enter(sceneName, ctx): Moves a user to the given scene. If sceneName is null, the user leaves any current scene.
• handleMessage(ctx): Dispatches the incoming message to the correct scene's onMessage callback.

class Scene

Represents a multi-step conversation flow.

Constructor:

const myScene = new Scene('myScene');

Takes a name for identification.

• onEnter(fn): Registers a callback for when a user enters the scene.
• onLeave(fn): Registers a callback for when a user leaves the scene.
• onMessage(fn): Registers a callback for when the user sends a message in this scene.

All callbacks receive a context object ctx:

ctx.message - The Discord.Message object ctx.userId - The user's Discord ID (message.author.id) ctx.sessionData - An object for storing data relevant to the current scene

Extending

Custom Session Storage

Create a class that inherits SessionStore and implement getSession, setSession, and deleteSession using your preferred database (e.g., Redis or MongoDB).

Slash Commands

Instead of messageCreate and !start, you could handle interactionCreate for slash commands in Discord. The logic for Stage and Scene remains the same.

Multiple Scenes

If you have various flows (e.g., collecting feedback, ordering, or other steps), simply create additional scenes and stage.register(themAll).

License

MIT – use, modify, and distribute as needed.