add placeholder update checker using git changesets

include/functions2.php

@@ -203,6 +203,26 @@
 		return array($prefixes, $hotkeys);
 	}
 
+	function check_for_update() {
+		if (defined("GIT_VERSION_TIMESTAMP")) {
+			$content = @fetch_file_contents("http://tt-rss.org/version.json");
+
+			if ($content) {
+				$content = json_decode($content, true);
+
+				if ($content && isset($content["changeset"])) {
+					if ((int)GIT_VERSION_TIMESTAMP < (int)$content["changeset"]["timestamp"] &&
+						GIT_VERSION_HEAD != $content["changeset"]["id"]) {
+
+						return $content["changeset"]["id"];
+					}
+				}
+			}
+		}
+
+		return false;
+	}
+
 	function make_runtime_info() {
 		$data = array();
 
@@ -221,6 +241,15 @@
 		$data['dep_ts'] = calculate_dep_timestamp();
 		$data['reload_on_ts_change'] = !defined('_NO_RELOAD_ON_TS_CHANGE');
 
+
+		if (true || $_SESSION["last_version_check"] + 86400 + rand(-1000, 1000) < time()) {
+			$update_result = @check_for_update();
+
+			$data["update_result"] = $update_result;
+
+			$_SESSION["last_version_check"] = time();
+		}
+
 		if (file_exists(LOCK_DIRECTORY . "/update_daemon.lock")) {
 
 			$data['daemon_is_running'] = (int) file_is_locked("update_daemon.lock");

include/version.php

@@ -8,6 +8,10 @@
 		if (is_dir("$root_dir/.git") && file_exists("$root_dir/.git/refs/heads/master")) {
 
 			$suffix = substr(trim(file_get_contents("$root_dir/.git/refs/heads/master")), 0, 7);
+			$timestamp = filemtime("$root_dir/.git/refs/heads/master");
+
+			define("GIT_VERSION_HEAD", $suffix);
+			define("GIT_VERSION_TIMESTAMP", $timestamp);
 
 			return VERSION_STATIC . ".$suffix";
 		} else {

index.php

@@ -252,6 +252,10 @@
 					<?php } ?>
 				</div>
 			</div>
+
+			<button id="updatesIcon" dojoType="dijit.form.Button" style="display : none">
+				<img src="images/new_version.png" title="<?php echo __('Updates are available from Git.') ?>"/>
+			</button>
 		</div>
 	</div> <!-- toolbar -->
 </div> <!-- toolbar pane -->

js/tt-rss.js

@@ -767,6 +767,16 @@ function parse_runtime_info(data) {
 			return;
 		}
 
+		if (k == "update_result") {
+			var updatesIcon = dijit.byId("updatesIcon").domNode;
+
+			if (v != "") {
+				Element.show(updatesIcon);
+			} else {
+				Element.hide(updatesIcon);
+			}
+		}
+
 		if (k == "daemon_stamp_ok" && v != 1) {
 			notify_error("<span onclick=\"javascript:explainError(3)\">Update daemon is not updating feeds.</span>", true);
 			return;