Prevent background execution of zonal stats

This algorithm is NEVER safe to run in the background, because it directly modifies a layer in place. We should: - make a variant of this algorithm which returns a new layer AND - refactor the QgsZonalStats code to create a separate map of feature->stats, and then modify the existing Zonal Stats algorithm to apply these changes in a post processing step
qgis · Jun 8, 2018 · b637c7f · b637c7f
1 parent 6bf7c0e
commit b637c7f
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/python/plugins/processing/algs/qgis/ZonalStatistics.py b/python/plugins/processing/algs/qgis/ZonalStatistics.py
@@ -32,6 +32,7 @@
 
 from qgis.analysis import QgsZonalStatistics
 from qgis.core import (QgsProcessing,
+                       QgsProcessingAlgorithm,
                        QgsProcessingParameterVectorLayer,
                        QgsProcessingParameterRasterLayer,
                        QgsProcessingParameterString,
@@ -61,6 +62,9 @@ def group(self):
     def groupId(self):
         return 'rasteranalysis'
 
+    def flags(self):
+        return super().flags() | QgsProcessingAlgorithm.FlagNoThreading
+
     def __init__(self):
         super().__init__()
         self.bandNumber = None