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users System

users System

Tracks connected users in your A-Frame multiplayer scene using Colyseus.

Overview​

The users system automatically maintains a list of all connected players. It listens to Colyseus events and updates when users join, leave, or change their data.

Getting the User List​

const usersSystem = document.querySelector("a-scene").systems.users;
const users = usersSystem.getUsersList();

// users = [{id: 'abc123', username: 'Alice', el: <a-entity>, playerData: {...}}, ...]

Listening for Changes​

document.querySelector("a-scene").addEventListener("users-changed", (evt) => {
  const users = evt.detail.users;
  console.log(`${users.length} users online`);
});

User Object​

{
  id: 'abc123',          // Colyseus session ID
  username: 'Alice',     // Display name
  el: <a-entity>,        // A-Frame entity (may be null)
  playerData: {...}      // Colyseus player data
}

API​

getUsersList()​

Returns array of all connected users.

const users = this.el.sceneEl.systems.users.getUsersList();

Event: users-changed​

Fired when the user list updates.

scene.addEventListener("users-changed", (evt) => {
  const users = evt.detail.users;
});

Check if User is Online​

const users = scene.systems.users.getUsersList();
const isOnline = users.some((u) => u.username === "Alice");

Notes​

  • User entities (el) may be null if not yet spawned
  • Usernames are resolved from playerData.userName, playerData.name, or playerData.displayName