Do not resample data of sensors recording instantaneous values

documentation/changelog.rst

@@ -25,6 +25,7 @@ v0.11.1 | September XX, 2022
 
 Bugfixes
 -----------
+* Do not fail asset page if none of the sensors has any data [see `PR #492 <http://www.github.com/FlexMeasures/flexmeasures/pull/492>`_]
 * Do not fail asset page if one of the shown sensors records instantaneous values [see `PR #491 <http://www.github.com/FlexMeasures/flexmeasures/pull/491>`_]
 
 

flexmeasures/data/models/charts/belief_charts.py

@@ -72,13 +72,13 @@ def chart_for_multiple_sensors(
     **override_chart_specs: dict,
 ):
     sensors_specs = []
+    condition = (
+        sensor.event_resolution
+        for sensor in sensors
+        if sensor.event_resolution > timedelta(0)
+    )
     minimum_non_zero_resolution_in_ms = (
-        min(
-            sensor.event_resolution
-            for sensor in sensors
-            if sensor.event_resolution > timedelta(0)
-        ).total_seconds()
-        * 1000
+        min(condition).total_seconds() * 1000 if any(condition) else 0
     )
     for sensor in sensors:
         unit = sensor.unit if sensor.unit else "a.u."

flexmeasures/data/models/generic_assets.py

@@ -381,11 +381,14 @@ def search_beliefs(
             from flexmeasures.data.services.time_series import simplify_index
 
             if sensors:
-                minimum_non_zero_resolution = min(
+                condition = (
                     bdf.event_resolution
                     for bdf in bdf_dict.values()
                     if bdf.event_resolution > timedelta(0)
                 )
+                minimum_non_zero_resolution = (
+                    min(condition) if any(condition) else timedelta(0)
+                )
                 df_dict = {}
                 for sensor, bdf in bdf_dict.items():
                     if bdf.event_resolution > timedelta(0):