def add_source_field_or_expression(field_or_expression):
field_index = self.source_layer.fields().lookupField(
field_or_expression)
if field_index == -1:
expression = QgsExpression(field_or_expression)
if not expression.hasParserError():
expression.prepare(context)
return expression, expression.needsGeometry(
), expression.referencedColumns()
return None, False, {field_or_expression}
def _buildfromlayer(self, widget, layerconfig):
layername = layerconfig['layer']
keyfield = layerconfig['key']
valuefield = layerconfig['value']
filterexp = layerconfig.get('filter', None)
try:
layer = QgsMapLayerRegistry.instance().mapLayersByName(layername)[0]
except IndexError:
roam.utils.warning("Can't find layer {} in project".format(layername))
return
keyfieldindex = layer.fieldNameIndex(keyfield)
valuefieldindex = layer.fieldNameIndex(valuefield)
if keyfieldindex == -1 or valuefieldindex == -1:
roam.utils.warning("Can't find key or value column")
return
if not filterexp and valuefieldindex == keyfieldindex:
values = layer.uniqueValues(keyfieldindex)
for value in values:
widget.addItem(value, value)
return
attributes = {keyfieldindex, valuefieldindex}
flags = QgsFeatureRequest.NoGeometry
expression = None
if filterexp:
expression = QgsExpression(filterexp)
expression.prepare(layer.pendingFields())
if expression.hasParserError():
roam.utils.warning("Expression has parser error: {}".format(expression.parserErrorString()))
return
if expression.needsGeometry():
flags = QgsFeatureRequest.NoFlags
for field in expression.referencedColumns():
index = layer.fieldNameIndex(field)
attributes.add(index)
values = set()
request = QgsFeatureRequest().setFlags(flags).setSubsetOfAttributes(list(attributes))
for feature in layer.getFeatures(request):
if expression and not expression.evaluate(feature):
continue
widget.addItem(feature[keyfieldindex], feature[valuefield])
if self.allownulls:
widget.insertItem(0, '(no selection)', None)
def calculate( self, layer, fieldName, expression ):
if ( layer.featureCount() == 0 ):
self.msg.show( "[Info] * No existing features on layer " + layer.name() + " to calculate expression.", 'info', True )
return
expression = QgsExpression( expression )
if expression.hasParserError():
self.msg.show( QApplication.translate( "AutoFields-FieldCalculator", "[Error] (Parsing) " ) + \
expression.parserErrorString(), 'critical' )
return
context = QgsExpressionContext()
context.appendScope( QgsExpressionContextUtils.globalScope() )
context.appendScope( QgsExpressionContextUtils.projectScope() )
context.appendScope( QgsExpressionContextUtils.layerScope( layer ) )
context.setFields( layer.fields() )
if expression.needsGeometry():
if self.iface:
# This block was borrowed from QGIS/python/plugins/processing/algs/qgis/FieldsCalculator.py
da = QgsDistanceArea()
da.setSourceCrs( layer.crs().srsid() )
da.setEllipsoidalMode( self.iface.mapCanvas().mapSettings().hasCrsTransformEnabled() )
da.setEllipsoid( QgsProject.instance().readEntry( 'Measure', '/Ellipsoid', GEO_NONE )[0] )
expression.setGeomCalculator( da )
if QGis.QGIS_VERSION_INT >= 21400: # Methods added in QGIS 2.14
expression.setDistanceUnits( QgsProject.instance().distanceUnits() )
expression.setAreaUnits( QgsProject.instance().areaUnits() )
expression.prepare( context )
fieldIndex = layer.fieldNameIndex( fieldName )
if fieldIndex == -1:
return
field = layer.fields()[fieldIndex]
dictResults = {}
for feature in layer.getFeatures():
context.setFeature( feature )
result = expression.evaluate( context )
if expression.hasEvalError():
self.msg.show( QApplication.translate( "AutoFields-FieldCalculator", "[Error] (Evaluating) " ) + \
expression.evalErrorString(), 'critical' )
return
dictResults[feature.id()] = { fieldIndex: field.convertCompatible( result ) }
layer.dataProvider().changeAttributeValues( dictResults )
self.msg.show( "[Info] * An expression was calculated on existing features of layer " + layer.name() + ", field " + fieldName + ".", 'info', True )
def _buildfromlayer(self, widget, layerconfig):
layername = layerconfig['layer']
keyfield = layerconfig['key']
valuefield = layerconfig['value']
filterexp = layerconfig.get('filter', None)
try:
layer = QgsMapLayerRegistry.instance().mapLayersByName(
layername)[0]
except IndexError:
roam.utils.warning(
"Can't find layer {} in project".format(layername))
return
keyfieldindex = layer.fieldNameIndex(keyfield)
valuefieldindex = layer.fieldNameIndex(valuefield)
if keyfieldindex == -1 or valuefieldindex == -1:
roam.utils.warning("Can't find key or value column")
return
if self.allownulls:
item = QStandardItem('(no selection)')
item.setData(None, Qt.UserRole)
self.listmodel.appendRow(item)
attributes = {keyfieldindex, valuefieldindex}
iconfieldindex = layer.fieldNameIndex('icon')
if iconfieldindex > -1:
attributes.add(iconfieldindex)
if not filterexp and valuefieldindex == keyfieldindex and iconfieldindex == -1:
values = layer.uniqueValues(keyfieldindex)
for value in values:
value = nullconvert(value)
item = QStandardItem(value)
item.setData(value, Qt.UserRole)
self.listmodel.appendRow(item)
return
flags = QgsFeatureRequest.NoGeometry
expression = None
if filterexp:
expression = QgsExpression(filterexp)
expression.prepare(layer.pendingFields())
if expression.hasParserError():
roam.utils.warning("Expression has parser error: {}".format(
expression.parserErrorString()))
return
if expression.needsGeometry():
flags = QgsFeatureRequest.NoFlags
for field in expression.referencedColumns():
index = layer.fieldNameIndex(field)
attributes.add(index)
request = QgsFeatureRequest().setFlags(flags).setSubsetOfAttributes(
list(attributes))
for feature in layer.getFeatures(request):
if expression and not expression.evaluate(feature):
continue
keyvalue = nullconvert(feature[keyfieldindex])
valuvalue = nullconvert(feature[valuefield])
try:
path = feature[iconfieldindex]
icon = QIcon(path)
except KeyError:
icon = QIcon()
item = QStandardItem(unicode(keyvalue))
item.setData(unicode(valuvalue), Qt.UserRole)
item.setIcon(icon)
self.listmodel.appendRow(item)
def _buildfromlayer(self, widget, layerconfig):
layername = layerconfig['layer']
keyfield = layerconfig['key']
valuefield = layerconfig['value']
filterexp = layerconfig.get('filter', None)
try:
layer = QgsMapLayerRegistry.instance().mapLayersByName(layername)[0]
except IndexError:
roam.utils.warning("Can't find layer {} in project".format(layername))
return
keyfieldindex = layer.fieldNameIndex(keyfield)
valuefieldindex = layer.fieldNameIndex(valuefield)
if keyfieldindex == -1 or valuefieldindex == -1:
roam.utils.warning("Can't find key or value column")
return
if self.allownulls:
item = QStandardItem('(no selection)')
item.setData(None, Qt.UserRole)
self.listmodel.appendRow(item)
attributes = {keyfieldindex, valuefieldindex}
iconfieldindex = layer.fieldNameIndex('icon')
if iconfieldindex > -1:
attributes.add(iconfieldindex)
if not filterexp and valuefieldindex == keyfieldindex and iconfieldindex == -1:
values = layer.uniqueValues(keyfieldindex)
for value in values:
value = nullconvert(value)
item = QStandardItem(value)
item.setData(value, Qt.UserRole)
self.listmodel.appendRow(item)
return
flags = QgsFeatureRequest.NoGeometry
expression = None
if filterexp:
expression = QgsExpression(filterexp)
expression.prepare(layer.pendingFields())
if expression.hasParserError():
roam.utils.warning("Expression has parser error: {}".format(expression.parserErrorString()))
return
if expression.needsGeometry():
flags = QgsFeatureRequest.NoFlags
for field in expression.referencedColumns():
index = layer.fieldNameIndex(field)
attributes.add(index)
request = QgsFeatureRequest().setFlags(flags).setSubsetOfAttributes(list(attributes))
for feature in layer.getFeatures(request):
if expression and not expression.evaluate(feature):
continue
keyvalue = nullconvert(feature[keyfieldindex])
valuvalue = nullconvert(feature[valuefield])
try:
path = feature[iconfieldindex]
icon = QIcon(path)
except KeyError:
icon = QIcon()
item = QStandardItem(unicode(keyvalue))
item.setData(unicode(valuvalue), Qt.UserRole)
item.setIcon(icon)
self.listmodel.appendRow(item)
def expressionBasedUpdate( self, layer, dictProperties, featureId, index=None, value=None ):
""" Defines the logic of the expression-based update to be applied.
This SLOT listens to featureAdded, geometryChanged, and attributeValueChanged SIGNALS.
"""
# Check if AutoField is there, otherwise return
fieldIndex = layer.fieldNameIndex( dictProperties['field'] )
if fieldIndex == -1:
self.msg.show(
QApplication.translate( "EventManager", "[Error] Updating AutoField " ) + \
dictProperties['field'] + \
QApplication.translate( "EventManager", " in layer " ) + \
layer.name() + QApplication.translate( "EventManager", " was NOT possible." ) + \
QApplication.translate( "EventManager", " Perhaps you just removed it but haven't saved the changes yet?" ),
'warning' )
return
event = ""
result = None
expression = QgsExpression( dictProperties['expression'] )
if expression.hasParserError():
self.msg.show( QApplication.translate( "EventManager", "[Error] (Parsing) " ) + \
expression.parserErrorString(), 'critical' )
result = NULL
# Avoid infinite recursion (changing the same attribute value infinitely).
if not index is None: # Filters out the featureAdded SIGNAL
if type( index ) == int: # Filters out the geometryChanged SIGNAL
if index == fieldIndex: # This call comes from the same AutoField, so return
return
if self.afm.isFieldAnAutoField( layer, layer.fields()[index].name() ): # Call from AutoField, don't listen
# This is to prevent corrupting the layerEditBuffer and being bitten by:
# Fatal: ASSERT: "mChangedAttributeValues.isEmpty()" in file /tmp/buildd/qgis-2.14.2+20trusty/src/core/qgsvectorlayereditbuffer.cpp, line 585
return
#if type(value)==QPyNullVariant:
# Vector layers with numeric field whose value for 1st feature is NULL
# trigger an attributeValueChanged SIGNAL when start editing from the
# attribute table window. We use this conditional to avoid such SIGNAL.
# The ideal case is that such NULL valued SIGNAL shouldn't be emitted by QGIS.
# return
# While the previous block reduces the number of times attributeValueChanged
# is called from the attribute table, it leads to a QGIS bug:
# Fatal: ASSERT: "mChangedAttributeValues.isEmpty()" in file /tmp/buildd/qgis-2.14.2+20trusty/src/core/qgsvectorlayereditbuffer.cpp, line 585
# I prefer the attributeValueChanged to be called multiple
# times (inefficient) than to open the possibility to a bug.
# As soon as QGIS bug #15272 is solved, the number of calls will be reduced!
event = "attributeValueChanged"
else:
event = "geometryChanged"
else:
event = "featureAdded"
feature = layer.getFeatures( QgsFeatureRequest( featureId ) ).next()
if result is None:
context = QgsExpressionContext()
context.appendScope( QgsExpressionContextUtils.globalScope() )
context.appendScope( QgsExpressionContextUtils.projectScope() )
context.appendScope( QgsExpressionContextUtils.layerScope( layer ) )
context.setFields( feature.fields() )
context.setFeature( feature )
if expression.needsGeometry():
if self.iface:
# This block was borrowed from QGIS/python/plugins/processing/algs/qgis/FieldsCalculator.py
da = QgsDistanceArea()
da.setSourceCrs( layer.crs().srsid() )
da.setEllipsoidalMode( self.iface.mapCanvas().mapSettings().hasCrsTransformEnabled() )
da.setEllipsoid( QgsProject.instance().readEntry( 'Measure', '/Ellipsoid', GEO_NONE )[0] )
expression.setGeomCalculator( da )
if QGis.QGIS_VERSION_INT >= 21400: # Methods added in QGIS 2.14
expression.setDistanceUnits( QgsProject.instance().distanceUnits() )
expression.setAreaUnits( QgsProject.instance().areaUnits() )
expression.prepare( context )
result = expression.evaluate( context )
if expression.hasEvalError():
self.msg.show( QApplication.translate( "EventManager", "[Error] (Evaluating) " ) + \
expression.evalErrorString(), 'critical' )
result = NULL
field = layer.fields()[fieldIndex]
res = field.convertCompatible( result )
# If result is None, res will be None, but even in that case, QGIS knows
# what to do with it while saving, it seems it's treated as NULL.
# TODO when bug #15311 is fixed, this block should work better
#if dictProperties['expression'] in self.listProviderExpressions:
# # Save directly to provider
# layer.dataProvider().changeAttributeValues( { featureId : { fieldIndex : res } } )
#else: # Save to layer
# layer.changeAttributeValue( featureId, fieldIndex, res )
# Workaround
if event == 'featureAdded': # Save directly to the provider
layer.dataProvider().changeAttributeValues( { featureId : { fieldIndex : res } } )
else: # Save to layer
layer.changeAttributeValue( featureId, fieldIndex, res )
self.msg.show( "[Info] * AutoField's value updated to " + unicode(res) + \
", (" + layer.name() + "." + dictProperties['field'] + ") by " + event +".", 'info', True )
def expressionBasedUpdate(self,
layer,
dictProperties,
featureId,
index=None,
value=None):
""" Defines the logic of the expression-based update to be applied.
This SLOT listens to featureAdded, geometryChanged, and attributeValueChanged SIGNALS.
"""
# Check if AutoField is there, otherwise return
fieldIndex = layer.fieldNameIndex(dictProperties['field'])
if fieldIndex == -1:
self.msg.show(
QApplication.translate( "EventManager", "[Error] Updating AutoField " ) + \
dictProperties['field'] + \
QApplication.translate( "EventManager", " in layer " ) + \
layer.name() + QApplication.translate( "EventManager", " was NOT possible." ) + \
QApplication.translate( "EventManager", " Perhaps you just removed it but haven't saved the changes yet?" ),
'warning' )
return
event = ""
result = None
expression = QgsExpression(dictProperties['expression'])
if expression.hasParserError():
self.msg.show( QApplication.translate( "EventManager", "[Error] (Parsing) " ) + \
expression.parserErrorString(), 'critical' )
result = NULL
# Avoid infinite recursion (changing the same attribute value infinitely).
if not index is None: # Filters out the featureAdded SIGNAL
if type(index) == int: # Filters out the geometryChanged SIGNAL
if index == fieldIndex: # This call comes from the same AutoField, so return
return
if self.afm.isFieldAnAutoField(
layer,
layer.fields()
[index].name()): # Call from AutoField, don't listen
# This is to prevent corrupting the layerEditBuffer and being bitten by:
# Fatal: ASSERT: "mChangedAttributeValues.isEmpty()" in file /tmp/buildd/qgis-2.14.2+20trusty/src/core/qgsvectorlayereditbuffer.cpp, line 585
return
#if type(value)==QPyNullVariant:
# Vector layers with numeric field whose value for 1st feature is NULL
# trigger an attributeValueChanged SIGNAL when start editing from the
# attribute table window. We use this conditional to avoid such SIGNAL.
# The ideal case is that such NULL valued SIGNAL shouldn't be emitted by QGIS.
# return
# While the previous block reduces the number of times attributeValueChanged
# is called from the attribute table, it leads to a QGIS bug:
# Fatal: ASSERT: "mChangedAttributeValues.isEmpty()" in file /tmp/buildd/qgis-2.14.2+20trusty/src/core/qgsvectorlayereditbuffer.cpp, line 585
# I prefer the attributeValueChanged to be called multiple
# times (inefficient) than to open the possibility to a bug.
# As soon as QGIS bug #15272 is solved, the number of calls will be reduced!
event = "attributeValueChanged"
else:
event = "geometryChanged"
else:
event = "featureAdded"
feature = layer.getFeatures(QgsFeatureRequest(featureId)).next()
if result is None:
context = QgsExpressionContext()
context.appendScope(QgsExpressionContextUtils.globalScope())
context.appendScope(QgsExpressionContextUtils.projectScope())
context.appendScope(QgsExpressionContextUtils.layerScope(layer))
context.setFields(feature.fields())
context.setFeature(feature)
if expression.needsGeometry():
if self.iface:
# This block was borrowed from QGIS/python/plugins/processing/algs/qgis/FieldsCalculator.py
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(self.iface.mapCanvas().mapSettings().
hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
expression.setGeomCalculator(da)
if QGis.QGIS_VERSION_INT >= 21400: # Methods added in QGIS 2.14
expression.setDistanceUnits(
QgsProject.instance().distanceUnits())
expression.setAreaUnits(
QgsProject.instance().areaUnits())
expression.prepare(context)
result = expression.evaluate(context)
if expression.hasEvalError():
self.msg.show( QApplication.translate( "EventManager", "[Error] (Evaluating) " ) + \
expression.evalErrorString(), 'critical' )
result = NULL
field = layer.fields()[fieldIndex]
res = field.convertCompatible(result)
# If result is None, res will be None, but even in that case, QGIS knows
# what to do with it while saving, it seems it's treated as NULL.
# TODO when bug #15311 is fixed, this block should work better
#if dictProperties['expression'] in self.listProviderExpressions:
# # Save directly to provider
# layer.dataProvider().changeAttributeValues( { featureId : { fieldIndex : res } } )
#else: # Save to layer
# layer.changeAttributeValue( featureId, fieldIndex, res )
# Workaround
if event == 'featureAdded': # Save directly to the provider
layer.dataProvider().changeAttributeValues(
{featureId: {
fieldIndex: res
}})
else: # Save to layer
layer.changeAttributeValue(featureId, fieldIndex, res)
self.msg.show( "[Info] * AutoField's value updated to " + unicode(res) + \
", (" + layer.name() + "." + dictProperties['field'] + ") by " + event +".", 'info', True )
