added get_dev_reading_time to read the timestamp of a reading

fhem/fhem/__init__.py

@@ -439,6 +439,42 @@ def get_dev_readings(self, dev, readings, timeout=0.1):
                     print("E - Reading not defined:", dev, reading)
         return reads
 
+    def get_dev_reading_time(self, dev, reading, timeout=0.1):
+        '''Get the date and time of a specific reading from a FHEM device
+        :param dev: FHEM device
+        :param reading: name of FHEM reading
+        :param timeout: timeout for reply'''
+        read = None
+        state = self.get_dev_state(dev, timeout=timeout)
+        if state == {}:
+            return None
+        try:
+            read = state['Results'][0]['Readings'][reading]['Time']
+        except:
+            if self.loglevel > 0:
+                print("E - Reading not defined:", dev, reading)
+            return read
+        return read
+
+    def get_dev_readings_time(self, dev, readings, timeout=0.1):
+        '''Get a list of dates and times of readings for one FHEM device
+        :param dev: FHEM device
+        'param readings': array of FHEM reading names
+        :param timeout: timeout for reply'''
+        reads = {}
+        state = self.get_dev_state(dev, timeout=timeout)
+        if state == {}:
+            return reads
+        for reading in readings:
+            try:
+                rr1 = state['Results'][0]
+                reads[reading] = rr1['Readings'][reading]['Time']
+            except:
+                if self.loglevel > 0:
+                    print("E - Reading not defined:", dev, reading)
+        return reads
+
+
     def getFhemState(self, timeout=0.1):
         if self.loglevel > 0:
             print("Deprecation: use get_fhem_state instead of getFhemState")