Added live data functionnality + some docs in Python and JS code

influxgraph.py

@@ -32,6 +32,7 @@ class InfluxGraph:
         self.livemode = self.HISTORICAL
         self.time = [0, 0]
         self.lastvalues = {}
+        self.variables = []
 
     def get_abs_time(self, times):
         """
@@ -60,7 +61,7 @@ class InfluxGraph:
         # if self.livemode == self.LIVE:
         for c in result.values():
             while c:
-                lastt, lastx = c[-1]
+                lastt, _ = c[-1]
                 if lastt <= self.time[1]:
                     break
                 c.pop()
@@ -144,6 +145,10 @@ class InfluxGraph:
         end_time = int(self.get_abs_time(time)[-1])
         
         blocks = self.influx_data_getter.get_available_variables_at_time(end_time)
+
+        # updates the self.variables attribute to keep track of the available variables
+        self.variables = [variable["name"] for block in blocks for variable in block["curves"]]
+
         assign_colors_to_curves(blocks)
         result = dict(type='var_list')
         result['blocks'] = blocks
@@ -151,19 +156,48 @@ class InfluxGraph:
 
     def w_updategraph(self):
         """
-        TODO : method needed for live data update. See example in seaweb.py : SeaGraph
-
-        OLD : update live values - seems not to work
-        Sets the current visualisation mode to LIVE.
+        Sets the current visualisation mode to LIVE if not in HISTORICAL mode.
         Called when the route /updategraph is reached.
         Returns :
             {"type":"accept-graph", "live": bool} : a dict with its "accept-graph" type and a "live" value telling if the server could change its visualization mode to live
         """
-
-        return dict(type='accept-graph', live=False)
+        logging.info("UPD GRAPH %d", self.livemode)
+        if self.livemode == self.HISTORICAL:
+            return dict(type='accept-graph', live=False)
+        else:
+            self.livemode = self.LIVE
+            return dict(type='accept-graph', live=True)
 
     def graphpoll(self):
         """
-        TODO : method needed for live data update. See example in seaweb.py : SeaGraph
+        Polls the last known values for all the available variables, and returns only those whose polled value is more recent than the nost recent displayed one.
+        Every plain minute, all the variables are returned with a point having their last known value at the current timestamp to synchronize all the curves on the GUI.
+        
+        Returns :
+            {"type":"graph-update", "reduced":(bool), "time":(int), "graph":{(str):[[(int),(float)]]}} | None : a dictionnary with its "graph-update" type 
+                (so it can be processed by the client), a "reduced" value indicating if the data is reduced or not (meaning the data is sampled to be lighter 
+                for data viewing), and a "graph" dictionnary with the variable names as key, and an array of points, which are an array containing the timestamp 
+                as their first value, and the y-value in float as their second one
         """
+        if self.livemode == self.LIVE:
+            self.time[1], = self.get_abs_time([0])
+        else:
+            self.time[1] = self.time[0] # Do not update (the current requested value is the last)
+        if self.time[1] > self.time[0]:
+            result = self.influx_data_getter.poll_last_value(self.variables, self.time)
+        
+            for variable in self.lastvalues.keys():
+                if result[variable][-1][0] > self.lastvalues[variable][0]:
+                    self.lastvalues[variable] = (result[variable][-1][0], result[variable][-1][1])
+                else:
+                    del result[variable]
+
+            if int(self.time[1] / 60) != int(self.time[0] / 60):
+                # Update unchanged values every plain minute
+                for var, (_, lastx) in self.lastvalues.items():
+                    if var not in result:
+                        result[var] = [(self.time[1], lastx)]
+            self.time[0] = self.time[1]
+            if len(result) > 0:
+                return dict(type='graph-update', reduced=False, time=self.time[1], graph=result)
         return None