Creating Modules in RPGJS

Guide for Creating Modules in RPGJS in RPGJS.

Creating Modules in RPGJS

This guide explains how to create and structure modules in RPGJS using defineModule and createModule.

Module Structure

A typical module consists of three main files:

• server.ts - Server-side logic and hooks
• client.ts - Client-side logic and hooks
• index.ts - Module configuration and dependency injection

Step 1: Define Server-Side Module

Create a server.ts file using defineModule to define server-side behavior:

import { RpgEvent, RpgPlayer, type RpgServer } from "@rpgjs/server";
import { defineModule } from "@rpgjs/common";

export default defineModule<RpgServer>({
    player: {},
})

Step 2: Define Client-Side Module

Create a client.ts file using defineModule for client-side logic:

import { RpgClient, RpgClientEngine } from "@rpgjs/client";
import { defineModule } from "@rpgjs/common";

export default defineModule<RpgClient>({
    // Client-side hooks and logic
    // Add your client-side event handlers here
})

Step 3: Create Module with Dependency Injection

Create an index.ts file using createModule to configure the module and its dependencies:

import server from "./server";
import client from "./client";
import { createModule } from "@rpgjs/common";
import { BattleAi } from "./ai";

export function provideBattle() {
  return createModule("Battle", [
    {
      server,
      client,
    },
  ]);
}

Understanding createModule Parameters

The createModule function takes two parameters:

1. Token Name (First Parameter)

• Purpose: Unique identifier for dependency injection
• Usage: Allows other modules to inject this module as a dependency
• Example: "Battle" can be injected elsewhere using this token

2. Dependencies Array (Second Parameter)

The array can contain two types of objects:

Dependency Injection Objects

{
  provide: "BattleActionRpg",  // Token name for injection
  useClass: BattleAi,          // Class to instantiate
}

Server/Client Extension Objects

{
  server,  // Extends server-side functionality
  client,  // Extends client-side functionality
}

How Hooks Work

When you include server and client objects in the createModule array, they extend the core modules with additional hooks:

• Server hooks: Extend RpgServer with custom player and event behaviors
• Client hooks: Extend RpgClient with custom client-side logic
• Event-driven: Hooks are automatically called at specific game events

Example Usage

// In your main game configuration
import { provideBattle } from "./modules/battle";

const gameModules = [
  provideBattle(),
  // other modules...
];

This modular approach allows for clean separation of concerns, easy testing, and flexible dependency management in your RPGJS game.