Refactor fields configuration in the modeler does not insist on layer

m-kuhn · m-kuhn · commit b619dcb00a74 · 2017-12-14T09:04:07.000+01:00
Inside the modeler, there is not enough knowledge about the layer on
which the refactor fields algorithm will run.
Let's be graceful with error messages here therefore.
diff --git a/python/plugins/processing/algs/qgis/FieldsMapper.py b/python/plugins/processing/algs/qgis/FieldsMapper.py
@@ -137,8 +137,8 @@ def prepareAlgorithm(self, parameters, context, feedback):
             if expression.hasParserError():
                 raise QgsProcessingException(
                     self.tr(u'Parser error in expression "{}": {}')
-                    .format(str(expression.expression()),
-                            str(expression.parserErrorString())))
+                    .format(expression.expression(),
+                            expression.parserErrorString()))
             self.expressions.append(expression)
         return True
 
@@ -160,8 +160,8 @@ def processFeature(self, feature, context, feedback):
             if expression.hasEvalError():
                 raise QgsProcessingException(
                     self.tr(u'Evaluation error in expression "{}": {}')
-                        .format(str(expression.expression()),
-                                str(expression.parserErrorString())))
+                        .format(expression.expression(),
+                                expression.parserErrorString()))
             attributes.append(value)
         feature.setAttributes(attributes)
         self._row_number += 1
diff --git a/python/plugins/processing/algs/qgis/ui/FieldsMappingPanel.py b/python/plugins/processing/algs/qgis/ui/FieldsMappingPanel.py
@@ -225,8 +225,7 @@ def loadLayerFields(self, layer):
 
         self._mapping = []
         if layer is not None:
-            dp = layer.dataProvider()
-            for field in dp.fields():
+            for field in layer.fields():
                 self._mapping.append(self.newField(field))
 
         self.endResetModel()
@@ -263,6 +262,7 @@ def createEditor(self, parent, option, index):
         editor.registerExpressionContextGenerator(index.model().contextGenerator())
         editor.fieldChanged.connect(self.on_expression_fieldChange)
         editor.setAutoFillBackground(True)
+        editor.setAllowEvalErrors(self.parent().dialogType == DIALOG_MODELER)
         return editor
 
     def setEditorData(self, editor, index):
@@ -303,6 +303,7 @@ def __init__(self, parent=None):
 
         self.layerCombo.setAllowEmptyLayer(True)
         self.layerCombo.setFilters(QgsMapLayerProxyModel.VectorLayer)
+        self.dialogType = None
 
     def configure(self):
         self.model = FieldsMappingModel()
@@ -472,7 +473,9 @@ def __init__(self, *args, **kwargs):
         self._layer = None
 
     def createWidget(self):
-        return FieldsMappingPanel()
+        panel = FieldsMappingPanel()
+        panel.dialogType = self.dialogType
+        return panel
 
     def postInitialize(self, wrappers):
         for wrapper in wrappers:
