From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Sun, 21 Jun 2015 13:34:19 +0000 (+0200)
Subject: Add a mechanism for the server to ask the client to upgrade itself.
X-Git-Url: https://git.sesse.net/?p=remoteglot;a=commitdiff_plain;h=9d0e6d5379e906fb387e5a48982f3dc6d76cefdb

Add a mechanism for the server to ask the client to upgrade itself.
---

diff --git a/www/js/remoteglot.js b/www/js/remoteglot.js
index 440419f..6844428 100644
--- a/www/js/remoteglot.js
+++ b/www/js/remoteglot.js
@@ -1,5 +1,14 @@
 (function() {
 
+/**
+ * Version of this script. If the server returns a version larger than
+ * this, it is a sign we should reload to upgrade ourselves.
+ *
+ * @type {Number}
+ * @const
+ * @private */
+var SCRIPT_VERSION = 2015062103;
+
 /** @type {window.ChessBoard} @private */
 var board = null;
 
@@ -144,6 +153,13 @@ var request_update = function() {
 		} else {
 			new_data = data;
 		}
+
+		var minimum_version = xhr.getResponseHeader('X-RGMV');
+		if (minimum_version && minimum_version > SCRIPT_VERSION) {
+			// Upgrade to latest version with a force-reload.
+			location.reload(true);
+		}
+
 		possibly_play_sound(current_analysis_data, new_data);
 		current_analysis_data = new_data;
 		update_board(current_analysis_data, displayed_analysis_data);
diff --git a/www/serve-analysis.js b/www/serve-analysis.js
index 0faf92f..751a0ff 100644
--- a/www/serve-analysis.js
+++ b/www/serve-analysis.js
@@ -13,6 +13,7 @@ var delta = require('./js/json_delta.js');
 // Constants.
 var JSON_FILENAME = '/srv/analysis.sesse.net/www/analysis.json';
 var HISTORY_TO_KEEP = 5;
+var MINIMUM_VERSION = null;
 
 // If set to 1, we are already processing a JSON update and should not
 // start a new one. If set to 2, we are _also_ having one in the queue.
@@ -186,6 +187,10 @@ var send_json = function(response, ims, accept_gzip, num_viewers) {
 		'Vary': 'Accept-Encoding',
 	};
 
+	if (MINIMUM_VERSION) {
+		headers['X-RGMV'] = MINIMUM_VERSION;
+	}
+
 	if (accept_gzip) {
 		headers['Content-Length'] = this_json.gzip.length;
 		headers['Content-Encoding'] = 'gzip';