Add very basic support for viewing probe readings as graph

can only view the last hour of readings, so far

tailbone/templates/tempmon/probes/graph.mako

@@ -0,0 +1,66 @@
+## -*- coding: utf-8; -*-
+<%inherit file="/base.mako" />
+
+<%def name="title()">Temperature Graph</%def>
+
+<%def name="extra_javascript()">
+  ${parent.extra_javascript()}
+  <script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.5.0/Chart.bundle.min.js"></script>
+  <script type="text/javascript">
+
+    $(function() {
+
+        var ctx = $('#tempchart');
+
+        var chart = new Chart(ctx, {
+            type: 'scatter',
+            data: {
+                datasets: [{
+                    label: "${probe.description}",
+                    data: ${json.dumps(readings_data)|n}
+                }]
+            },
+            options: {
+                scales: {
+                    xAxes: [{
+                        type: 'time',
+                        time: {unit: 'minute'},
+                        position: 'bottom'
+                    }]
+                }
+            }
+        });
+
+    });
+
+  </script>
+</%def>
+
+<div class="form-wrapper">
+
+  <div class="field-wrapper">
+    <label>Appliance</label>
+    <div class="field">
+      % if probe.appliance:
+          <a href="${url('tempmon.appliances.view', uuid=probe.appliance.uuid)}">${probe.appliance}</a>
+      % endif
+    </div>
+  </div>
+
+  <div class="field-wrapper">
+    <label>Probe Location</label>
+    <div class="field">${probe.location}</div>
+  </div>
+
+  <div class="field-wrapper">
+    <label>Showing</label>
+    <div class="field">
+      <select name="showing-window" id="showing-window" auto-enhance="true">
+        <option value="last-hour">Last Hour</option>
+      </select>
+    </div>
+  </div>
+
+</div>
+
+<canvas id="tempchart" width="400" height="150"></canvas>

tailbone/templates/tempmon/probes/view.mako

@@ -41,6 +41,11 @@
 ## rendering methods
 ##############################
 
+<%def name="context_menu_items()">
+  ${parent.context_menu_items()}
+  <li>${h.link_to("View Readings as Graph", action_url('graph', instance))}</li>
+</%def>
+
 <%def name="render_main_fields(form)">
   ${form.render_field_readonly('client')}
   ${form.render_field_readonly('config_key')}

tailbone/views/tempmon/probes.py

@@ -26,8 +26,11 @@ Views for tempmon probes
 
 from __future__ import unicode_literals, absolute_import
 
+import datetime
+
 import six
 
+from rattail.time import make_utc, localtime
 from rattail_tempmon.db import model as tempmon
 
 import colander
@@ -220,6 +223,46 @@ class TempmonProbeView(MasterView):
 
         g.set_sort_defaults('taken', 'desc')
 
+    def graph(self):
+        probe = self.get_instance()
+
+        # figure out which readings we need to graph
+        # TODO: make this dynamic somehow
+        cutoff = make_utc() - datetime.timedelta(seconds=3600) # last hour
+        readings = self.Session.query(tempmon.Reading)\
+                               .filter(tempmon.Reading.probe == probe)\
+                               .filter(tempmon.Reading.taken >= cutoff)\
+                               .order_by(tempmon.Reading.taken)\
+                               .all()
+
+        # convert readings to data for scatter plot
+        data = [{
+            'x': localtime(self.rattail_config, reading.taken, from_utc=True).isoformat(),
+            'y': float(reading.degrees_f),
+        } for reading in readings]
+
+        context = {
+            'probe': probe,
+            'parent_title': six.text_type(probe),
+            'parent_url': self.get_action_url('view', probe),
+            'readings_data': data,
+        }
+        return self.render_to_response('graph', context)
+
+    @classmethod
+    def defaults(cls, config):
+        route_prefix = cls.get_route_prefix()
+        url_prefix = cls.get_url_prefix()
+        model_key = cls.get_model_key()
+        permission_prefix = cls.get_permission_prefix()
+        model_title_plural = cls.get_model_title_plural()
+
+        config.add_route('{}.graph'.format(route_prefix), '{}/{{{}}}/graph'.format(url_prefix, model_key))
+        config.add_view(cls, attr='graph', route_name='{}.graph'.format(route_prefix),
+                        permission='{}.view'.format(permission_prefix))
+
+        cls._defaults(config)
+
 
 def includeme(config):
     TempmonProbeView.defaults(config)