Move the keepalive functionality from Empires up to Game

[empires-server] / game.js

diff --git a/game.js b/game.js
index 20cd2411e2275ff8aef51e1c35a3772931815b6b..ca12fb3e6d302470f5cb1ce946907f3361c50474 100644 (file)
--- a/game.js
+++ b/game.js
@@ -1,9 +1,32 @@
 /* Base class providing common code for game engine implementations. */
 class Game {
-  constructor(name) {
-    this.name = name;
+  constructor(id) {
+    this.id = id;
     this.clients = [];
     this.next_client_id = 1;
+
+    /* Send a comment to every connected client every 15 seconds. */
+    setInterval(() => {this.broadcast_string(":");}, 15000);
+  }
+
+  /* Suport for game meta-data.
+   *
+   * What we want here is an effectively static field that is
+   * accessible through either the class name (SomeGame.meta) or an
+   * instance (some_game.meta). To pull this off we do keep two copies
+   * of the data. But the game classes can just set SomeGame.meta once
+   * and then reference it either way.
+   */
+  static set meta(data) {
+    /* This allows class access (SomeGame.meta) via the get method below. */
+    this._meta = data;
+
+    /* While this allows access via an instance (some_game.meta). */
+    this.prototype.meta = data;
+  }
+
+  static get meta() {
+    return this._meta;
   }
 
   add_client(response) {
@@ -49,6 +72,17 @@ class Game {
     request.on('close', () => {
       this.remove_client(id);
     });
+
+    /* Finally, if this game class has a "state" property, stream that
+     * current state to the client. */
+    if (this.state) {
+      const state_json = JSON.stringify(this.state);
+      response.write(`event: game-state\ndata: ${state_json}\n\n`);
+    }
+  }
+
+  broadcast_move(move) {
+    this.broadcast_event("move", move);
   }
 
 }