Move info window message creation to Go instead of Javascript

main.go

@@ -40,6 +40,7 @@ func main() {
 	r.HandleFunc("/vehicles", App.VehiclesHandler).Methods("GET")
 	r.HandleFunc("/vehicles/create", App.VehiclesCreateHandler).Methods("POST")
 	r.HandleFunc("/updates", App.UpdatesHandler).Methods("GET")
+  r.HandleFunc("/updates/message", App.UpdateMessageHandler).Methods("GET")
 	r.HandleFunc("/routes", App.RoutesHandler).Methods("GET")
 	r.HandleFunc("/routes/create", App.RoutesCreateHandler).Methods("POST")
 	r.HandleFunc("/stops", App.StopsHandler).Methods("GET")

static/components/shuttles-map.html

@@ -66,6 +66,12 @@
       handle-as="json"
       on-response="placeStops">
     </iron-ajax>
+    <iron-ajax
+      id="fetchMessages"
+      url="/updates/message"
+      handle-as="json"
+      last-response="{{messages}}">
+    </iron-ajax>
 
     <google-map id="shuttleMap" class="shuttle-map" zoom="{{zoom}}" latitude="{{lat}}" longitude="{{lng}}"></google-map>
     <div id="logo">
@@ -138,6 +144,10 @@
         stops: {
           type: Array,
           value: []
+        },
+        messages: {
+          type: Array,
+          value: []
         }
       },
 
@@ -150,6 +160,7 @@
       },
 
       initializeTracking: function() {
+        this.$.fetchMessages.generateRequest();
         this.$.fetchRoutes.generateRequest();
         this.$.fetchUpdates.generateRequest();
         this.$.fetchStops.generateRequest();
@@ -158,6 +169,7 @@
 
       periodicUpdates: function() {
         // periodically check for vehicle & route updates
+        setInterval(this.checkForUpdates, 15000, this.$.fetchMessages);
         setInterval(this.checkForUpdates, 15000, this.$.fetchUpdates);
         setInterval(this.checkForUpdates, 15000, this.$.fetchRoutes);
         setInterval(this.checkForUpdates, 15000, this.$.fetchStops);
@@ -167,20 +179,6 @@
         ajax.generateRequest();
       },
 
-      // Translate heading (0-360 degrees) to cardinal direction
-      cardinalDirection: function(heading) {
-        switch (true) {
-          case (heading >= 22.5 && heading < 67.5):   return "North-East";
-          case (heading >= 67.5 && heading < 112.5):  return "East";
-          case (heading >= 112.5 && heading < 157.5): return "South-East";
-          case (heading >= 157.5 && heading < 202.5): return "South";
-          case (heading >= 202.5 && heading < 247.5): return "South-West";
-          case (heading >= 247.5 && heading < 292.5): return "West";
-          case (heading >= 292.5 && heading < 337.5): return "North-West";
-          default:                                    return "North";
-        }
-      },
-
       placeVehicles: function(event, response) {
         var updates = response.response;
         if (updates) {
@@ -200,15 +198,10 @@
               title: updates[i]["vehicleID"]
             });
 
-            // Get cardinal direction for info window
-            var cardinal_dir = this.cardinalDirection(updates[i]["heading"]);
+            // Get update message for the info window
+            var contentString = this.messages[i];
             // Create info window and open it when shuttle clicked
             (function(marker, i) {
-              /* Include ID, heading, speed, time in the infowindow */
-              var contentString = '<b>Shuttle ID: ' + updates[i]["vehicleID"] + '</b><br />' +
-              'Traveling ' + cardinal_dir + ' at ' + updates[i]["speed"].substring(0,4) + 'mph<br />' +
-              'as of ' + updates[i]["time"].substring(0,2) + ':' + updates[i]["time"].substring(2,4) + ':' + updates[i]["time"].substring(4,6);
-
               var infowindow = new google.maps.InfoWindow({
                 content: contentString
               });

tracking/vehicles.go

@@ -7,6 +7,8 @@ import (
 	"regexp"
 	"strings"
 	"time"
+  "fmt"
+  "strconv"
 
 	log "github.com/Sirupsen/logrus"
 	"gopkg.in/mgo.v2/bson"
@@ -175,3 +177,52 @@ func (App *App) UpdatesHandler(w http.ResponseWriter, r *http.Request) {
 	// Convert updates to JSON
 	WriteJSON(w, updates)
 }
+
+// UpdateMessageHandler generates a message about an update for a vehicle
+func (App *App) UpdateMessageHandler(w http.ResponseWriter, r *http.Request) {
+  // For each vehicle/update, store message as a string
+  var messages []string
+  var message string
+  var vehicles []Vehicle
+  var update VehicleUpdate
+  // Query all Vehicles
+	err := App.Vehicles.Find(bson.M{}).All(&vehicles)
+	// Handle errors
+	if err != nil {
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+	}
+  // Find recent updates and generate message
+  for _, vehicle := range vehicles {
+    err := App.Updates.Find(bson.M{"vehicleID": vehicle.VehicleID}).Sort("-created").Limit(1).One(&update)
+    if (err == nil) {
+      // Use first 4 char substring of update.Speed
+      speed := update.Speed
+      if (len(speed) > 4) {
+        speed = speed[0:4] 
+      }
+      message = fmt.Sprintf("<b>%s</b><br/>Traveling %s at<br/> %s mph as of %s", vehicle.VehicleName, CardinalDirection(&update.Heading), speed, update.Created.Format("3:04PM"))
+      messages = append(messages, message)
+    }
+  }
+  // Convert to JSON
+  WriteJSON(w, messages)
+}
+
+// CardinalDirection figures out the cardinal direction of a vehicle's heading
+func CardinalDirection(h *string) string {
+  heading, err := strconv.ParseFloat(*h,64)
+  if (err != nil) {
+    fmt.Println("ERROR",err.Error())
+    return "North"
+  }
+  switch {
+    case (heading >= 22.5 && heading < 67.5):   return "North-East"
+    case (heading >= 67.5 && heading < 112.5):  return "East"
+    case (heading >= 112.5 && heading < 157.5): return "South-East"
+    case (heading >= 157.5 && heading < 202.5): return "South"
+    case (heading >= 202.5 && heading < 247.5): return "South-West"
+    case (heading >= 247.5 && heading < 292.5): return "West"
+    case (heading >= 292.5 && heading < 337.5): return "North-West"
+    default:                                    return "North"
+  }
+}