Add 'not selected' option for optional layer parameters in processing…

… model view Fixes #19329 (https://issues.qgis.org/issues/19329) Optional layer parameters in processing algorithms used in the graphical modeler add an empty string as the default parameter value, which can raise an exception during algorithm execution. This update replaces the default empty string with a default 'Not selected' option.
qgis · Jul 4, 2018 · 57fb4ef · 57fb4ef
1 parent 7b751cb
commit 57fb4ef
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/python/plugins/processing/gui/wrappers.py b/python/plugins/processing/gui/wrappers.py
@@ -864,10 +864,10 @@ def createWidget(self):
             self.combo = QComboBox()
             layers = self.getAvailableLayers()
             self.combo.setEditable(True)
+            if self.param.flags() & QgsProcessingParameterDefinition.FlagOptional:
+                self.combo.addItem(self.NOT_SELECTED, self.NOT_SET_OPTION)
             for layer in layers:
                 self.combo.addItem(self.dialog.resolveValueDescription(layer), layer)
-            if self.param.flags() & QgsProcessingParameterDefinition.FlagOptional:
-                self.combo.setEditText("")
 
             widget = QWidget()
             layout = QHBoxLayout()