time system is required for telemetry

Simplify realtime provider Due to nasa/openmct#1594 we no longer need to worry about multiple calls for the same identifier. Host all routes on same port, use host-relative urls for client Update readme
nasa · Oct 17, 2017 · b1c24b4 · b1c24b4
1 parent 88c54bf
commit b1c24b4
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Showing 9 changed files with 93 additions and 111 deletions.
diff --git a/README.md b/README.md
@@ -65,6 +65,7 @@ We're going to define a single `index.html` page.  We'll include the Open MCT li
         openmct.install(openmct.plugins.MyItems());
         openmct.install(openmct.plugins.UTCTimeSystem());
         openmct.time.clock('local', {start: -15 * 60 * 1000, end: 0});
+        openmct.time.timeSystem('utc');
         openmct.install(openmct.plugins.Espresso());
 
         openmct.start();
@@ -128,6 +129,7 @@ Next, we'll update index.html to include the file:
         openmct.install(openmct.plugins.MyItems());
         openmct.install(openmct.plugins.UTCTimeSystem());
         openmct.time.clock('local', {start: -15 * 60 * 1000, end: 0});
+        openmct.time.timeSystem('utc');
         openmct.install(openmct.plugins.Espresso());
 
         openmct.install(DictionaryPlugin());
@@ -416,7 +418,7 @@ function HistoricalTelemetryPlugin() {
                 return domainObject.type === 'example.telemetry';
             },
             request: function (domainObject, options) {
-                var url = 'http://localhost:8081/telemetry/' +
+                var url = '/history/' +
                     domainObject.identifier.key +
                     '?start=' + options.start +
                     '&end=' + options.end;
@@ -457,6 +459,7 @@ With our adapter defined, we need to update `index.html` to include it.
         openmct.install(openmct.plugins.MyItems());
         openmct.install(openmct.plugins.UTCTimeSystem());
         openmct.time.clock('local', {start: -15 * 60 * 1000, end: 0});
+        openmct.time.timeSystem('utc');
         openmct.install(openmct.plugins.Espresso());
 
         openmct.install(DictionaryPlugin());
@@ -484,39 +487,26 @@ Let's define our new plugin in a file named `realtime-telemetry-plugin.js`.
  */
 function RealtimeTelemetryPlugin() {
     return function (openmct) {
-        var socket = new WebSocket('ws://localhost:8082');
-        var listeners = {};
+        var socket = new WebSocket(location.origin.replace(/^http/, 'ws') + '/realtime/');
+        var listener = {};
 
         socket.onmessage = function (event) {
             point = JSON.parse(event.data);
-            if (listeners[point.id]) {
-                listeners[point.id].forEach(function (l) {
-                    l(point);
-                });
+            if (listener[point.id]) {
+                listener[point.id](point);
             }
         };
 
         var provider = {
             supportsSubscribe: function (domainObject) {
                 return domainObject.type === 'example.telemetry';
             },
-            subscribe: function (domainObject, callback, options) {
-                if (!listeners[domainObject.identifier.key]) {
-                    listeners[domainObject.identifier.key] = [];
-                }
-                if (!listeners[domainObject.identifier.key].length) {
-                    socket.send('subscribe ' + domainObject.identifier.key);
-                }
-                listeners[domainObject.identifier.key].push(callback);
-                return function () {
-                    listeners[domainObject.identifier.key] = 
-                        listeners[domainObject.identifier.key].filter(function (c) {
-                            return c !== callback;
-                        });
-
-                    if (!listeners[domainObject.identifier.key].length) {
-                        socket.send('unsubscribe ' + domainObject.identifier.key);
-                    }
+            subscribe: function (domainObject, callback) {
+                listener[domainObject.identifier.key] = callback;
+                socket.send('subscribe ' + domainObject.identifier.key);
+                return function unsubscribe() {
+                    delete listener[domainObject.identifier.key];
+                    socket.send('unsubscribe ' + domainObject.identifier.key);
                 };
             }
         };
@@ -549,6 +539,7 @@ With our realtime telemetry plugin defined, let's include it from `index.html`.
         openmct.install(openmct.plugins.MyItems());
         openmct.install(openmct.plugins.UTCTimeSystem());
         openmct.time.clock('local', {start: -15 * 60 * 1000, end: 0});
+        openmct.time.timeSystem('utc');
         openmct.install(openmct.plugins.Espresso());
 
         openmct.install(DictionaryPlugin());

diff --git a/example-server/history-server.js b/example-server/history-server.js
@@ -1,20 +1,13 @@
-
-
 var express = require('express');
 
-function HistoryServer(spacecraft, port) {
-    server = express();
+function HistoryServer(spacecraft) {
+    var router = express.Router();
 
-    server.use(function (req, res, next) {
-        res.set('Access-Control-Allow-Origin', '*');
-        next();
-    });
-
-    server.get('/telemetry/:pointId', function (req, res) {
+    router.get('/:pointId', function (req, res) {
         var start = +req.query.start;
         var end = +req.query.end;
         var ids = req.params.pointId.split(',');
-    
+
         var response = ids.reduce(function (resp, id) {
             return resp.concat(spacecraft.history[id].filter(function (p) {
                 return p.timestamp > start && p.timestamp < end;
@@ -23,8 +16,7 @@ function HistoryServer(spacecraft, port) {
         res.status(200).json(response).end();
     });
 
-    server.listen(port);
-    console.log('History server now running at http://localhost:' + port);
+    return router;
 }
 
 module.exports = HistoryServer;

diff --git a/example-server/realtime-server.js b/example-server/realtime-server.js
@@ -1,43 +1,41 @@
-var WebSocketServer = require('ws').Server;
-
-function RealtimeServer(spacecraft, port) {
-    this.spacecraft = spacecraft;
-    this.server = new WebSocketServer({ port: port });
-    this.server.on('connection', this.handleConnection.bind(this));
-    console.log('Realtime server started at ws://localhost:' + port);
-};
+var express = require('express');
+
+function RealtimeServer(spacecraft) {
+
+    var router = express.Router();
+
+    router.ws('/', function (ws) {
+        var unlisten = spacecraft.listen(notifySubscribers);
+        var subscribed = {}; // Active subscriptions for this connection
+        var handlers = { // Handlers for specific requests
+                subscribe: function (id) {
+                    subscribed[id] = true;
+                },
+                unsubscribe: function (id) {
+                    delete subscribed[id];
+                }
+            };
+
+        function notifySubscribers(point) {
+            if (subscribed[point.id]) {
+                ws.send(JSON.stringify(point));
+            }
+        }
 
-RealtimeServer.prototype.handleConnection = function (ws) {
-    var unlisten = this.spacecraft.listen(notifySubscribers);
-        subscribed = {}, // Active subscriptions for this connection
-        handlers = { // Handlers for specific requests
-            subscribe: function (id) {
-                subscribed[id] = true;
-            },
-            unsubscribe: function (id) {
-                delete subscribed[id];
+        // Listen for requests
+        ws.on('message', function (message) {
+            var parts = message.split(' '),
+                handler = handlers[parts[0]];
+            if (handler) {
+                handler.apply(handlers, parts.slice(1));
             }
-        };
+        });
 
-    function notifySubscribers(point) {
-        if (subscribed[point.id]) {
-            ws.send(JSON.stringify(point));
-        }
-    }
-
-    // Listen for requests
-    ws.on('message', function (message) {
-        var parts = message.split(' '),
-            handler = handlers[parts[0]];
-        if (handler) {
-            handler.apply(handlers, parts.slice(1));
-        }
+        // Stop sending telemetry updates for this connection when closed
+        ws.on('close', unlisten);
     });
 
-    // Stop sending telemetry updates for this connection when closed
-    ws.on('close', unlisten);
+    return router;
 };
 
-
-
-module.exports = RealtimeServer;
+module.exports = RealtimeServer;
diff --git a/example-server/server.js b/example-server/server.js
@@ -7,9 +7,23 @@ var RealtimeServer = require('./realtime-server');
 var HistoryServer = require('./history-server');
 var StaticServer = require('./static-server');
 
+var expressWs = require('express-ws');
+var app = require('express')();
+expressWs(app);
 
 var spacecraft = new Spacecraft();
-var realtimeServer = new RealtimeServer(spacecraft, 8082);
-var historyServer = new HistoryServer(spacecraft, 8081);
-var staticServer = new StaticServer(8080);
+var realtimeServer = new RealtimeServer(spacecraft);
+var historyServer = new HistoryServer(spacecraft);
+var staticServer = new StaticServer();
 
+app.use('/realtime', realtimeServer);
+app.use('/history', historyServer);
+app.use('/', staticServer);
+
+var port = process.env.PORT || 8080
+
+app.listen(port, function () {
+    console.log('Open MCT hosted at http://localhost:' + port);
+    console.log('History hosted at http://localhost:' + port + '/history');
+    console.log('Realtime hosted at ws://localhost:' + port + '/realtime');
+});
diff --git a/example-server/static-server.js b/example-server/static-server.js
@@ -1,13 +1,11 @@
 var express = require('express');
 
-function StaticServer(port) {
-    var server = express();
-
-    server.use('/', express.static(__dirname + '/..'));
-
-    console.log('Open MCT hosted at http://localhost:' + port);
-
-    server.listen(port);
+function StaticServer() {
+    var router = express.Router();
+
+    router.use('/', express.static(__dirname + '/..'));
+
+    return router
 }
 
-module.exports = StaticServer;
+module.exports = StaticServer;
diff --git a/historical-telemetry-plugin.js b/historical-telemetry-plugin.js
@@ -9,7 +9,7 @@ function HistoricalTelemetryPlugin() {
                 return domainObject.type === 'example.telemetry';
             },
             request: function (domainObject, options) {
-                var url = 'http://localhost:8081/telemetry/' +
+                var url = '/history/' +
                     domainObject.identifier.key +
                     '?start=' + options.start +
                     '&end=' + options.end;

diff --git a/index.html b/index.html
@@ -15,6 +15,7 @@
         openmct.install(openmct.plugins.MyItems());
         openmct.install(openmct.plugins.UTCTimeSystem());
         openmct.time.clock('local', {start: -15 * 60 * 1000, end: 0});
+        openmct.time.timeSystem('utc');
         openmct.install(openmct.plugins.Espresso());
 
         openmct.install(DictionaryPlugin());

diff --git a/package.json b/package.json
@@ -19,7 +19,8 @@
   "homepage": "https://github.com/nasa/openmct-tutorial#readme",
   "dependencies": {
     "express": "^4.14.1",
-    "ws": "^2.0.3",
-    "openmct": "nasa/openmct"
+    "express-ws": "^3.0.0",
+    "openmct": "nasa/openmct",
+    "ws": "^2.0.3"
   }
 }
diff --git a/realtime-telemetry-plugin.js b/realtime-telemetry-plugin.js
@@ -3,39 +3,26 @@
  */
 function RealtimeTelemetryPlugin() {
     return function (openmct) {
-        var socket = new WebSocket('ws://localhost:8082');
-        var listeners = {};
+        var socket = new WebSocket(location.origin.replace(/^http/, 'ws') + '/realtime/');
+        var listener = {};
 
         socket.onmessage = function (event) {
             point = JSON.parse(event.data);
-            if (listeners[point.id]) {
-                listeners[point.id].forEach(function (l) {
-                    l(point);
-                });
+            if (listener[point.id]) {
+                listener[point.id](point);
             }
         };
 
         var provider = {
             supportsSubscribe: function (domainObject) {
                 return domainObject.type === 'example.telemetry';
             },
-            subscribe: function (domainObject, callback, options) {
-                if (!listeners[domainObject.identifier.key]) {
-                    listeners[domainObject.identifier.key] = [];
-                }
-                if (!listeners[domainObject.identifier.key].length) {
-                    socket.send('subscribe ' + domainObject.identifier.key);
-                }
-                listeners[domainObject.identifier.key].push(callback);
-                return function () {
-                    listeners[domainObject.identifier.key] =
-                        listeners[domainObject.identifier.key].filter(function (c) {
-                            return c !== callback;
-                        });
-
-                    if (!listeners[domainObject.identifier.key].length) {
-                        socket.send('unsubscribe ' + domainObject.identifier.key);
-                    }
+            subscribe: function (domainObject, callback) {
+                listener[domainObject.identifier.key] = callback;
+                socket.send('subscribe ' + domainObject.identifier.key);
+                return function unsubscribe() {
+                    delete listener[domainObject.identifier.key];
+                    socket.send('unsubscribe ' + domainObject.identifier.key);
                 };
             }
         };