Use the same routes for all pages and plots

templates/boxplot.html

@@ -33,11 +33,11 @@
   </div>
 
   <div>
-    <input type="checkbox" id="check-overlay" onclick="location.href = '{{ url_for('overlay') }}';">
+    <input type="checkbox" id="check-overlay" onclick="location.href = '{{ url_for('page', plot_name='overlay') }}';">
     <label for="check-overlay">Overlay second dataset</label>
   </div>
   <div>
-    <input type="checkbox" id="check-boxplot" checked onclick="location.href = '{{ url_for('home') }}';">
+    <input type="checkbox" id="check-boxplot" checked onclick="location.href = '{{ url_for('page', plot_name='index') }}';">
     <label for="check-boxplot">Boxplot multiple years</label>
   </div>
 </div>

templates/index.html

@@ -28,11 +28,11 @@
   </div>
 
   <div>
-    <input type="checkbox" id="check-overlay" onclick="location.href = '{{ url_for('overlay') }}';">
+    <input type="checkbox" id="check-overlay" onclick="location.href = '{{ url_for('page', plot_name='overlay') }}';">
     <label for="check-overlay">Overlay second dataset</label>
   </div>
   <div>
-    <input type="checkbox" id="check-boxplot" onclick="location.href = '{{ url_for('boxplot') }}';">
+    <input type="checkbox" id="check-boxplot" onclick="location.href = '{{ url_for('page', plot_name='boxplot') }}';">
     <label for="check-boxplot">Boxplot multiple years</label>
   </div>
 </div>

templates/overlay.html

@@ -28,11 +28,11 @@
   </div>
 
   <div>
-    <input type="checkbox" id="check-overlay" checked onclick="location.href = '{{ url_for('home') }}';">
+    <input type="checkbox" id="check-overlay" checked onclick="location.href = '{{ url_for('page', plot_name='index') }}';">
     <label for="check-overlay">Overlay second dataset</label>
   </div>
   <div>
-    <input type="checkbox" id="check-boxplot" onclick="location.href = '{{ url_for('boxplot') }}';">
+    <input type="checkbox" id="check-boxplot" onclick="location.href = '{{ url_for('page', plot_name='boxplot') }}';">
     <label for="check-boxplot">Boxplot multiple years</label>
   </div>
 

visualizer.py

@@ -35,22 +35,23 @@ plt.rcParams['axes.xmargin'] = 0
 matplotlib.use('Agg')
 
 
-@app.route('/')
-def home():
-    populate_g()
-    return render_template('index.html')
+@app.route('/', defaults={'plot_name': 'index'})
+@app.route('/<plot_name>')
+def page(plot_name):
+    """Render a visualizer page."""
+    if plot_name not in plotters:
+        abort(404)
 
+    stations = read_stations()
+    g.stations = stations
 
-@app.route('/overlay')
-def overlay():
-    populate_g()
-    return render_template('overlay.html')
+    def id_years(station):
+        years = [record['year'] for record in station['records']]
+        return station['id'], years
 
+    g.record_years = dict(map(id_years, stations))
 
-@app.route('/boxplot')
-def boxplot():
-    populate_g()
-    return render_template('boxplot.html')
+    return render_template(f'{plot_name}.html')
 
 
 @app.route('/record/link')
@@ -61,8 +62,32 @@ def record_link():
     return jsonify(get_link(station, year))
 
 
-@app.route('/plot')
-def plot():
+@app.route('/plot', defaults={'plot_name': 'index'})
+@app.route('/plot/<plot_name>')
+def plot(plot_name):
+    """Create a data plot image."""
+    plotter = plotters.get(plot_name)
+    if plotter is None:
+        abort(404)
+    return plotter.plot()
+
+
+Plotter = make_dataclass('Plotter', ['name', 'plot'])
+plotters = {}
+
+
+def add_plotter(name):
+    """Decorator to register a plot type."""
+
+    def decorator(f):
+        plotters[name] = Plotter(name, f)
+        return f
+
+    return decorator
+
+
+@add_plotter('index')
+def plot_index():
     """Plot one station/year/measurement."""
     station_id = get_param('station')
     year = get_param('year', to=year_type)
@@ -94,7 +119,7 @@ def plot():
     return savefig_response(fig)
 
 
-@app.route('/plot/overlay')
+@add_plotter('overlay')
 def plot_overlay():
     """Plot two station/years @ one measurement."""
     num_datasets = 2
@@ -152,7 +177,7 @@ def plot_overlay():
     return savefig_response(fig)
 
 
-@app.route('/plot/boxplot')
+@add_plotter('boxplot')
 def plot_boxplot():
     """Boxplot one station/measurement @ multiple years."""
     station_id = get_param('station')
@@ -240,18 +265,6 @@ def savefig_response(fig):
     return Response(buf.getvalue(), mimetype='image/png')
 
 
-def populate_g():
-    """Populate `g` with data for rendering page templates."""
-    stations = read_stations()
-    g.stations = stations
-
-    def id_years(station):
-        years = [record['year'] for record in station['records']]
-        return station['id'], years
-
-    g.record_years = dict(map(id_years, stations))
-
-
 def read_stations():
     """Read amrdcrecords.json."""
     with open('amrdcrecords.json') as f: