game: Add support for a static "meta" field to hold game metadata

[empires-server] / game.js

diff --git a/game.js b/game.js
index f99ff234fa24c64aa9b9b362a6ad7c475902d5fb..5bbd7f503885a964105a90266f5e36d8cd981210 100644 (file)
--- a/game.js
+++ b/game.js
@@ -6,6 +6,26 @@ class Game {
     this.next_client_id = 1;
   }
 
+  /* 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) {
     const id = this.next_client_id;
     this.clients.push({id: id,
@@ -33,6 +53,24 @@ class Game {
     this.broadcast_string(`event: ${type}\ndata: ${data}\n`);
   }
 
+  handle_events(request, response) {
+    /* These headers will keep the connection open so we can stream events. */
+    const headers = {
+      "Content-type": "text/event-stream",
+      "Connection": "keep-alive",
+      "Cache-Control": "no-cache"
+    };
+    response.writeHead(200, headers);
+
+    /* Add this new client to our list of clients. */
+    const id = this.add_client(response);
+
+    /* And queue up cleanup to be triggered on client close. */
+    request.on('close', () => {
+      this.remove_client(id);
+    });
+  }
+
 }
 
 module.exports = Game;