fix a tiny bug in Video Stream

src/VideoStream/index.js

@@ -42,13 +42,13 @@ class VideoStream extends Component {
 
         this.store = new VideoStore();
 
-        // Automatically detect if the configured topic name is valid
-        this.hasTopic = observable.box(false);
-        this.searchForTopic()
-
         // Fill the undefined fields of the configuration object with their default values.
         defaultConfig(this.store);
         this.props.store.components['video'] = this.store;
+
+        // Automatically detect if the configured topic name is valid
+        this.hasTopic = observable.box(false);
+        this.searchForTopic();
     }
 
     defaultImage = 'images/default.svg';
@@ -62,7 +62,7 @@ class VideoStream extends Component {
     get streamUrl() {
         if ('url' in this.props && this.props.url) {
             return this.props.url;
-        } else if (this.hasTopic.get()) { 
+        } else if (this.hasTopic.get()) {
             // all requierd configuration fields are defined
             return 'http://' + this.store.config.host + '/stream?topic='
                     + this.store.config.topic;
@@ -74,7 +74,7 @@ class VideoStream extends Component {
     /**
      * Check that all the requirements are met for subscribing to the required
      * topic
-     * 
+     *
      * Thanks to MobX magic, the result is computed again each time the topic
      * configuration is changed.
      */
@@ -88,19 +88,18 @@ class VideoStream extends Component {
                     this.props.ros.getTopics(infos => {
                         this.hasTopic.set(undefined !== infos.topics.find(
                             elem => elem === this.store.config.topic));
-                            
+
                         if (!this.hasTopic.get()) {
                             console.warn("[VideoStream] The required topic "
                                 + this.store.config.topic + " is not published");
                         }
-                        console.debug(this.hasTopic.get());
                     })
                 } else {
                     console.warn("[VideoStream] either no topic is configured "
                         + "or no host is configured. This should never "
                         + "happen at runtime. Contact the developpers.");
                 }
-            })
+            }, {fireImmediately: true})
         } else {
             console.warn("[VideoStream] ROS property is provided. This should "
                 + "never happen at runtime. Contact the developpers.");