Change URL pattern for retrieving audio feature data

Added 'api' as a prefix to make the URL consistent with the genre data
retrieval URL.

spotifyvis/templates/spotifyvis/audio_features.html

@@ -50,7 +50,7 @@
                 // define the vertical scaling function
                 let vScale = d3.scaleLinear().range([height, 0]);
 
-                d3.json(`/audio_features/${audioFeature}/{{ user_secret }}`)
+                d3.json(`/api/audio_features/${audioFeature}/{{ user_secret }}`)
                     .then(function(response) {
                     // categorize the data points
                     for (let dataPoint of response.data_points) {

spotifyvis/urls.py

@@ -14,6 +14,6 @@ urlpatterns = [
     path('graphs/genre/<str:client_secret>', display_genre_graph,
         name='display_genre_graph'),
     path('audio_features/<str:client_secret>', audio_features, name='audio_features'),
-    path('audio_features/<str:audio_feature>/<str:client_secret>',
+    path('api/audio_features/<str:audio_feature>/<str:client_secret>',
         get_audio_feature_data, name='get_audio_feature_data'),
 ]

spotifyvis/views.py

@@ -205,6 +205,12 @@ def display_genre_graph(request, client_secret):
     return render(request, "spotifyvis/genre_graph.html", context)
 
 def audio_features(request, client_secret):
+    """Renders the audio features page
+
+    :param request: the HTTP request
+    :param client_secret: user secret used for identification
+    :return: renders the audio features page
+    """
     user = User.objects.get(user_secret=client_secret)
     context = {
         'user_id': user.user_id,