Merge pull request #299 from Workiva/fix_sockjs_detection

WP-5850 Use hasProperty to detect sockjs.js

CHANGELOG.md

@@ -1,17 +1,29 @@
-# Changelog
+## [3.2.1](https://github.com/Workiva/w_transport/compare/3.2.0...3.2.1)
+_January 29th, 2018_
+
+- **Bug Fix:** The `sockjs.js` detection now uses `context.hasProperty()`
+  instead of actually trying to access the `SockJS` object on the window. This
+  fixes an exception that was being thrown silently in certain situations.
 
 ## [3.2.0](https://github.com/Workiva/w_transport/compare/3.1.2...3.2.0)
-_January 4th, 2017_
+_January 4th, 2018_
 
-- **Improvement:** Added support for the [`sockjs_client_wrapper` package](https://github.com/Workiva/sockjs_client_wrapper). This will eventually replace our usage of the [`sockjs_client` Dart port](https://github.com/Workiva/sockjs-dart-client) because the wrapper uses the actual JS library which is fully-featured and community supported.
+- **Improvement:** Added support for the [`sockjs_client_wrapper` package](https://github.com/Workiva/sockjs_client_wrapper). This will eventually replace our usage of the [`sockjs_client` Dart port](https://github.com/Workiva/sockjs-dart-client)
+  because the wrapper uses the actual JS library which is fully-featured and community supported.
 
-    The SockJS wrapper requires that the JS library be included in the HTML page. To avoid a breaking change, it will only be used if the JS library is detected on the window.
+  The SockJS wrapper requires that the JS library be included in the HTML page.
+  To avoid a breaking change, it will only be used if the JS library is detected
+  on the window.
 
-    If you are using the SockJS configuration for `WebSocket` and wish to leverage this more fully-featured SockJS (which provides all of the SockJS protocols e.g. `xhr-polling`), all you need to do is add the JS script to your application page:
+  If you are using the SockJS configuration for `WebSocket` and wish to leverage
+  this more fully-featured SockJS (which provides all of the SockJS protocols
+  e.g. `xhr-polling`), all you need to do is add the JS script to your
+  application page:
 
-    https://github.com/workiva/sockjs_client_wrapper#usage
+  https://github.com/workiva/sockjs_client_wrapper#usage
 
-    If you don't change anything, the SockJS configuration for `WebSocket` will still behave exactly the same and you should see no difference.
+  If you don't change anything, the SockJS configuration for `WebSocket` will
+  still behave exactly the same and you should see no difference.
 
 ## [3.0.3](https://github.com/Workiva/w_transport/compare/3.0.2...3.0.3)
 _March 15th, 2017_

example/index.html

@@ -48,4 +48,4 @@ <h3>WebSocket</h3>
     <script type="application/dart" src="index.dart"></script>
     <script src="packages/browser/dart.js"></script>
 </body>
-</html>
+</html>

example/web_socket/echo/client.dart

@@ -36,7 +36,9 @@ TextInputElement _prompt = querySelector('#prompt');
 PreElement _logs = querySelector('#logs');
 NumberInputElement _sockJSTimeout = querySelector('#sockjs-timeout');
 CheckboxInputElement _sockJSWebSocket = querySelector('#sockjs-ws');
-CheckboxInputElement _sockJSXhr = querySelector('#sockjs-xhr');
+CheckboxInputElement _sockJSXhrStreaming =
+    querySelector('#sockjs-xhr-streaming');
+CheckboxInputElement _sockJSXhrPolling = querySelector('#sockjs-xhr-polling');
 CheckboxInputElement _useSockJS = querySelector('#sockjs');
 
 Future<Null> main() async {
@@ -60,9 +62,12 @@ Future<Null> main() async {
     if (_sockJSWebSocket.checked) {
       protocols.add('websocket');
     }
-    if (_sockJSXhr.checked) {
+    if (_sockJSXhrStreaming.checked) {
       protocols.add('xhr-streaming');
     }
+    if (_sockJSXhrPolling.checked) {
+      protocols.add('xhr-polling');
+    }
     final uri = sockjs ? _sockJSServer : _wsServer;
 
     try {

example/web_socket/echo/index.html

@@ -43,13 +43,20 @@ <h1>Echo</h1>
 
         <br>
 
-        <label for="sockjs-xhr">
-            <input type="checkbox" id="sockjs-xhr">
+        <label for="sockjs-xhr-streaming">
+            <input type="checkbox" id="sockjs-xhr-streaming">
             SockJS xhr-streaming
         </label>
 
         <br>
 
+        <label for="sockjs-xhr-polling">
+            <input type="checkbox" id="sockjs-xhr-polling">
+            SockJS xhr-polling
+        </label>
+
+        <br>
+
         <label for="sockjs-timeout">SockJS Timeout (ms)</label>
         <input type="number" id="sockjs-timeout">
 
@@ -67,6 +74,8 @@ <h1>Echo</h1>
     <pre id="logs"></pre>
 </div>
 
+<!--<script src="packages/sockjs_client_wrapper/sockjs.js"></script>-->
+<!--<script src="packages/sockjs_client_wrapper/sockjs_prod.js"></script>-->
 <script src="packages/react/react.js"></script>
 <script type="application/dart" src="client.dart"></script>
 <script src="packages/browser/dart.js"></script>

lib/src/web_socket/browser/sockjs.dart

@@ -34,7 +34,7 @@ abstract class SockJSWebSocket extends CommonWebSocket implements WebSocket {
     // which is community-supported and fully-featured. But, it requires that
     // the sockjs.js file is included. We can check for that by checking for the
     // existence of a `SockJS` object on the window.
-    if (js.context['SockJS'] != null && js.context['SockJS'] is js.JsFunction) {
+    if (js.context.hasProperty('SockJS')) {
       return SockJSWrapperWebSocket.connect(uri,
           debug: debug,
           noCredentials: noCredentials,