def prepareAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, 'INPUT', context)
mapping = self.parameterAsFieldsMapping(parameters, self.FIELDS_MAPPING, context)
self.fields = QgsFields()
self.expressions = []
da = QgsDistanceArea()
da.setSourceCrs(source.sourceCrs())
da.setEllipsoid(context.project().ellipsoid())
# create an expression context using thread safe processing context
self.expr_context = self.createExpressionContext(parameters, context, source)
for field_def in mapping:
self.fields.append(QgsField(name=field_def['name'],
type=field_def['type'],
typeName="",
len=field_def.get('length', 0),
prec=field_def.get('precision', 0)))
expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(context.project().distanceUnits())
expression.setAreaUnits(context.project().areaUnits())
if expression.hasParserError():
raise QgsProcessingException(
self.tr(u'Parser error in expression "{}": {}')
.format(str(expression.expression()),
str(expression.parserErrorString())))
self.expressions.append(expression)
return True
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
layer = self.parameterAsVectorLayer(parameters, self.INPUT, context)
field_name = self.parameterAsString(parameters, self.FIELD_NAME, context)
field_type = self.TYPES[self.parameterAsEnum(parameters, self.FIELD_TYPE, context)]
width = self.parameterAsInt(parameters, self.FIELD_LENGTH, context)
precision = self.parameterAsInt(parameters, self.FIELD_PRECISION, context)
new_field = self.parameterAsBool(parameters, self.NEW_FIELD, context)
formula = self.parameterAsString(parameters, self.FORMULA, context)
expression = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(source.sourceCrs())
da.setEllipsoid(context.project().ellipsoid())
expression.setGeomCalculator(da)
expression.setDistanceUnits(context.project().distanceUnits())
expression.setAreaUnits(context.project().areaUnits())
fields = source.fields()
field_index = fields.lookupField(field_name)
if new_field or field_index < 0:
fields.append(QgsField(field_name, field_type, '', width, precision))
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, source.wkbType(), source.sourceCrs())
exp_context = self.createExpressionContext(parameters, context)
if layer is not None:
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
if not expression.prepare(exp_context):
raise QgsProcessingException(
self.tr('Evaluation error: {0}').format(expression.parserErrorString()))
features = source.getFeatures()
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, f in enumerate(features):
if feedback.isCanceled():
break
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
feedback.reportError(expression.evalErrorString())
else:
attrs = f.attributes()
if new_field or field_index < 0:
attrs.append(value)
else:
attrs[field_index] = value
f.setAttributes(attrs)
sink.addFeature(f, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}
def createExpression(self, text, da, context):
expr = QgsExpression(text)
expr.setGeomCalculator(da)
expr.setDistanceUnits(context.project().distanceUnits())
expr.setAreaUnits(context.project().areaUnits())
if expr.hasParserError():
raise QgsProcessingException(
self.tr(u'Parser error in expression "{}": {}')
.format(text, expr.parserErrorString()))
return expr
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 prepareAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, 'INPUT', context)
if source is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, 'INPUT'))
mapping = self.parameterAsFieldsMapping(parameters,
self.FIELDS_MAPPING, context)
self.fields = QgsFields()
self.expressions = []
da = QgsDistanceArea()
da.setSourceCrs(source.sourceCrs(), context.transformContext())
da.setEllipsoid(context.project().ellipsoid())
# create an expression context using thread safe processing context
self.expr_context = self.createExpressionContext(
parameters, context, source)
for field_def in mapping:
self.fields.append(
QgsField(name=field_def['name'],
type=field_def['type'],
typeName="",
len=field_def.get('length', 0),
prec=field_def.get('precision', 0)))
if field_def['expression']:
expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(context.project().distanceUnits())
expression.setAreaUnits(context.project().areaUnits())
if expression.hasParserError():
feedback.reportError(
self.tr(u'Parser error in expression "{}": {}').format(
expression.expression(),
expression.parserErrorString()))
return False
self.expressions.append(expression)
else:
self.expressions.append(None)
return True
def processAlgorithm(self, progress):
layer = self.getParameterValue(self.INPUT_LAYER)
mapping = self.getParameterValue(self.FIELDS_MAPPING)
output = self.getOutputFromName(self.OUTPUT_LAYER)
layer = dataobjects.getObjectFromUri(layer)
fields = []
expressions = []
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
for field_def in mapping:
fields.append(
QgsField(name=field_def['name'],
type=field_def['type'],
len=field_def['length'],
prec=field_def['precision']))
expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(QgsProject.instance().distanceUnits())
expression.setAreaUnits(QgsProject.instance().areaUnits())
if expression.hasParserError():
raise GeoAlgorithmExecutionException(
self.tr(u'Parser error in expression "{}": {}').format(
str(field_def['expression']),
str(expression.parserErrorString())))
expression.prepare(exp_context)
if expression.hasEvalError():
raise GeoAlgorithmExecutionException(
self.tr(u'Evaluation error in expression "{}": {}').format(
str(field_def['expression']),
str(expression.evalErrorString())))
expressions.append(expression)
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs())
# Create output vector layer with new attributes
error = ''
calculationSuccess = True
inFeat = QgsFeature()
outFeat = QgsFeature()
features = vector.features(layer)
total = 100.0 / len(features)
for current, inFeat in enumerate(features):
rownum = current + 1
geometry = inFeat.geometry()
outFeat.setGeometry(geometry)
attrs = []
for i in range(0, len(mapping)):
field_def = mapping[i]
expression = expressions[i]
exp_context.setFeature(inFeat)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
calculationSuccess = False
error = expression.evalErrorString()
break
attrs.append(value)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
progress.setPercentage(int(current * total))
del writer
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation'
' string:\n') + error)
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, self.INPUT))
layer = self.parameterAsVectorLayer(parameters, self.INPUT, context)
field_name = self.parameterAsString(parameters, self.FIELD_NAME,
context)
field_type = self.TYPES[self.parameterAsEnum(parameters,
self.FIELD_TYPE, context)]
width = self.parameterAsInt(parameters, self.FIELD_LENGTH, context)
precision = self.parameterAsInt(parameters, self.FIELD_PRECISION,
context)
new_field = self.parameterAsBoolean(parameters, self.NEW_FIELD,
context)
formula = self.parameterAsString(parameters, self.FORMULA, context)
expression = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(source.sourceCrs(), context.transformContext())
da.setEllipsoid(context.project().ellipsoid())
expression.setGeomCalculator(da)
expression.setDistanceUnits(context.project().distanceUnits())
expression.setAreaUnits(context.project().areaUnits())
fields = source.fields()
field_index = fields.lookupField(field_name)
if new_field or field_index < 0:
fields.append(
QgsField(field_name, field_type, '', width, precision))
(sink, dest_id) = self.parameterAsSink(parameters,
self.OUTPUT, context, fields,
source.wkbType(),
source.sourceCrs())
if sink is None:
raise QgsProcessingException(
self.invalidSinkError(parameters, self.OUTPUT))
exp_context = self.createExpressionContext(parameters, context)
if layer is not None:
exp_context.appendScope(
QgsExpressionContextUtils.layerScope(layer))
expression.prepare(exp_context)
features = source.getFeatures()
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, f in enumerate(features):
if feedback.isCanceled():
break
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
feedback.reportError(expression.evalErrorString())
else:
attrs = f.attributes()
if new_field or field_index < 0:
attrs.append(value)
else:
attrs[field_index] = value
f.setAttributes(attrs)
sink.addFeature(f, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER))
fieldName = self.getParameterValue(self.FIELD_NAME)
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
width = self.getParameterValue(self.FIELD_LENGTH)
precision = self.getParameterValue(self.FIELD_PRECISION)
newField = self.getParameterValue(self.NEW_FIELD)
formula = self.getParameterValue(self.FORMULA)
output = self.getOutputFromName(self.OUTPUT_LAYER)
fields = layer.fields()
if newField:
fields.append(QgsField(fieldName, fieldType, '', width, precision))
writer = output.getVectorWriter(fields, layer.wkbType(),
layer.crs())
exp = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: %s' % exp.evalErrorString()))
outFeature = QgsFeature()
outFeature.initAttributes(len(fields))
outFeature.setFields(fields)
error = ''
calculationSuccess = True
features = vector.features(layer)
total = 100.0 / len(features)
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
break
else:
outFeature.setGeometry(f.geometry())
for fld in f.fields():
outFeature[fld.name()] = f[fld.name()]
outFeature[fieldName] = value
writer.addFeature(outFeature)
progress.setPercentage(int(current * total))
del writer
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation '
'string:\n%s' % error))
def processAlgorithm(self, context, feedback):
layer = self.getParameterValue(self.INPUT_LAYER)
mapping = self.getParameterValue(self.FIELDS_MAPPING)
output = self.getOutputFromName(self.OUTPUT_LAYER)
layer = QgsProcessingUtils.mapLayerFromString(layer, context)
fields = QgsFields()
expressions = []
da = QgsDistanceArea()
da.setSourceCrs(layer.crs())
da.setEllipsoid(QgsProject.instance().ellipsoid())
exp_context = layer.createExpressionContext()
for field_def in mapping:
fields.append(
QgsField(field_def['name'], field_def['type'],
field_def['length'], field_def['precision']))
expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(QgsProject.instance().distanceUnits())
expression.setAreaUnits(QgsProject.instance().areaUnits())
expression.prepare(exp_context)
if expression.hasParserError():
raise GeoAlgorithmExecutionException(
self.tr(u'Parser error in expression "{}": {}').format(
str(expression.expression()),
str(expression.parserErrorString())))
expressions.append(expression)
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs(),
context)
# Create output vector layer with new attributes
error_exp = None
inFeat = QgsFeature()
outFeat = QgsFeature()
features = QgsProcessingUtils.getFeatures(layer, context)
count = QgsProcessingUtils.featureCount(layer, context)
if count > 0:
total = 100.0 / count
for current, inFeat in enumerate(features):
rownum = current + 1
geometry = inFeat.geometry()
outFeat.setGeometry(geometry)
attrs = []
for i in range(0, len(mapping)):
field_def = mapping[i]
expression = expressions[i]
exp_context.setFeature(inFeat)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
error_exp = expression
break
attrs.append(value)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
feedback.setProgress(int(current * total))
else:
feedback.setProgress(100)
del writer
if error_exp is not None:
raise GeoAlgorithmExecutionException(
self.tr(u'Evaluation error in expression "{}": {}').format(
str(error_exp.expression()),
str(error_exp.parserErrorString())))
def processAlgorithm(self, progress):
layer = self.getParameterValue(self.INPUT_LAYER)
mapping = self.getParameterValue(self.FIELDS_MAPPING)
output = self.getOutputFromName(self.OUTPUT_LAYER)
layer = dataobjects.getObjectFromUri(layer)
fields = []
expressions = []
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp_context = layer.createExpressionContext()
for field_def in mapping:
fields.append(QgsField(name=field_def['name'],
type=field_def['type'],
len=field_def['length'],
prec=field_def['precision']))
expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(QgsProject.instance().distanceUnits())
expression.setAreaUnits(QgsProject.instance().areaUnits())
expression.prepare(exp_context)
if expression.hasParserError():
raise GeoAlgorithmExecutionException(
self.tr(u'Parser error in expression "{}": {}')
.format(unicode(expression.expression()),
unicode(expression.parserErrorString())))
expressions.append(expression)
writer = output.getVectorWriter(fields,
layer.wkbType(),
layer.crs())
# Create output vector layer with new attributes
error_exp = None
inFeat = QgsFeature()
outFeat = QgsFeature()
features = vector.features(layer)
total = 100.0 / len(features)
for current, inFeat in enumerate(features):
rownum = current + 1
geometry = inFeat.geometry()
outFeat.setGeometry(geometry)
attrs = []
for i in range(0, len(mapping)):
field_def = mapping[i]
expression = expressions[i]
exp_context.setFeature(inFeat)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
error_exp = expression
break
attrs.append(value)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat)
progress.setPercentage(int(current * total))
del writer
if error_exp is not None:
raise GeoAlgorithmExecutionException(
self.tr(u'Evaluation error in expression "{}": {}')
.format(unicode(error_exp.expression()),
unicode(error_exp.parserErrorString())))
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
layer = self.parameterAsVectorLayer(parameters, self.INPUT, context)
field_name = self.parameterAsString(parameters, self.FIELD_NAME, context)
field_type = self.TYPES[self.parameterAsEnum(parameters, self.FIELD_TYPE, context)]
width = self.parameterAsInt(parameters, self.FIELD_LENGTH, context)
precision = self.parameterAsInt(parameters, self.FIELD_PRECISION, context)
new_field = self.parameterAsBool(parameters, self.NEW_FIELD, context)
formula = self.parameterAsString(parameters, self.FORMULA, context)
expression = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(source.sourceCrs(), context.transformContext())
da.setEllipsoid(context.project().ellipsoid())
expression.setGeomCalculator(da)
expression.setDistanceUnits(context.project().distanceUnits())
expression.setAreaUnits(context.project().areaUnits())
field_index = layer.fields().lookupField(field_name)
if new_field or field_index < 0:
res = layer.dataProvider().addAttributes([QgsField(field_name, field_type, '', width, precision)])
if not res:
raise QgsProcessingException("The new field couldn't be created! We suggest you to create it using QGIS tools and then update its values with this algorithm.")
layer.updateFields()
field_index = layer.fields().lookupField(field_name)
field = layer.fields()[field_index]
exp_context = self.createExpressionContext(parameters, context)
if layer is not None:
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
expression.prepare(exp_context)
features = layer.getFeatures()
total = 100.0 / layer.featureCount() if layer.featureCount() else 0
dict_results = dict()
for current, f in enumerate(features):
if feedback.isCanceled():
break
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
feedback.reportError(expression.evalErrorString())
else:
dict_results[f.id()] = {field_index: field.convertCompatible(value)}
feedback.setProgress(int(current * total))
layer.dataProvider().changeAttributeValues(dict_results)
return {self.OUTPUT: layer}
def get_feature_with_form_scope(params: Dict[str, str], response: QgsServerResponse, project: QgsProject) -> None:
""" Get filtered features with a form scope
In parameters:
LAYER=wms-layer-name
FILTER=An expression to filter layer
FORM_FEATURE={"type": "Feature", "geometry": {}, "properties": {}}
// optionals
FIELDS=list of requested field separated by comma
WITH_GEOMETRY=False
"""
layer_name = params.get('LAYER', '')
if not layer_name:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'GetFeatureWithFormScope' REQUEST: LAYER parameter is mandatory",
400)
# get layer
layer = find_vector_layer(layer_name, project)
# layer not found
if not layer:
raise ExpressionServiceError(
"Bad request error",
"Invalid LAYER parameter for 'VirtualField': {} provided".format(layer_name),
400)
# get filter
exp_filter = params.get('FILTER', '')
if not exp_filter:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'GetFeatureWithFormScope' REQUEST: FILTER parameter is mandatory",
400)
# get form feature
form_feature = params.get('FORM_FEATURE', '')
if not form_feature:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'GetFeatureWithFormScope' REQUEST: FORM_FEATURE parameter is mandatory",
400)
# Check features
try:
geojson = json.loads(form_feature)
except Exception:
QgsMessageLog.logMessage(
"JSON loads form feature '{}' exception:\n{}".format(form_feature, traceback.format_exc()),
"lizmap", Qgis.Critical)
raise ExpressionServiceError(
"Bad request error",
"Invalid 'GetFeatureWithFormScope' REQUEST: FORM_FEATURE '{}' are not well formed".format(form_feature),
400)
if not geojson or not isinstance(geojson, dict):
raise ExpressionServiceError(
"Bad request error",
"Invalid 'GetFeatureWithFormScope' REQUEST: FORM_FEATURE '{}' are not well formed".format(form_feature),
400)
if ('type' not in geojson) or geojson['type'] != 'Feature':
raise ExpressionServiceError(
"Bad request error",
("Invalid 'GetFeatureWithFormScope' REQUEST: FORM_FEATURE '{}' are not well formed: type not defined "
"or not Feature.").format(form_feature),
400)
# try to load form feature
# read fields
form_feature_fields = QgsJsonUtils.stringToFields(
form_feature,
QTextCodec.codecForName("UTF-8"))
# read features
form_feature_list = QgsJsonUtils.stringToFeatureList(
form_feature,
form_feature_fields,
QTextCodec.codecForName("UTF-8"))
# features not well formed
if not form_feature_list:
raise ExpressionServiceError(
"Bad request error",
("Invalid FORM_FEATURE for 'GetFeatureWithFormScope': not GeoJSON feature provided\n"
"{}").format(form_feature),
400)
if len(form_feature_list) != 1:
raise ExpressionServiceError(
"Bad request error",
("Invalid FORM_FEATURE for 'GetFeatureWithFormScope': not GeoJSON feature provided\n"
"{}").format(form_feature),
400)
# Get the form feature
form_feat = form_feature_list[0]
# create expression context
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope(project))
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
exp_context.appendScope(QgsExpressionContextUtils.formScope(form_feat))
# create distance area context
da = QgsDistanceArea()
da.setSourceCrs(layer.crs(), project.transformContext())
da.setEllipsoid(project.ellipsoid())
# Get filter expression
exp_f = QgsExpression(exp_filter)
exp_f.setGeomCalculator(da)
exp_f.setDistanceUnits(project.distanceUnits())
exp_f.setAreaUnits(project.areaUnits())
if exp_f.hasParserError():
raise ExpressionServiceError(
"Bad request error",
"Invalid FILTER for 'GetFeatureWithFormScope': Error \"{}\": {}".format(
exp_filter, exp_f.parserErrorString()),
400)
if not exp_f.isValid():
raise ExpressionServiceError(
"Bad request error",
"Invalid FILTER for 'GetFeatureWithFormScope': Expression not valid \"{}\"".format(exp_filter),
400)
exp_f.prepare(exp_context)
req = QgsFeatureRequest(exp_f, exp_context)
# With geometry
with_geom = params.get('WITH_GEOMETRY', '').lower() in ['true', '1', 't']
if not with_geom:
req.setFlags(QgsFeatureRequest.NoGeometry)
# Fields
pk_attributes = layer.primaryKeyAttributes()
attribute_list = [i for i in pk_attributes]
fields = layer.fields()
r_fields = [f.strip() for f in params.get('FIELDS', '').split(',') if f]
for f in r_fields:
attribute_list.append(fields.indexOf(f))
# response
response.setStatusCode(200)
response.setHeader("Content-Type", "application/json")
response.write('{ "type": "FeatureCollection","features":[')
response.flush()
json_exporter = QgsJsonExporter(layer)
if attribute_list:
json_exporter.setAttributes(attribute_list)
separator = ''
for feat in layer.getFeatures(req):
fid = layer_name + '.' + get_server_fid(feat, pk_attributes)
response.write(separator + json_exporter.exportFeature(feat, {}, fid))
response.flush()
separator = ',\n'
response.write(']}')
return
def virtualFields(params: Dict[str, str], response: QgsServerResponse, project: QgsProject) -> None:
""" Get virtual fields for features
In parameters:
LAYER=wms-layer-name
VIRTUALS={"key1": "first expression", "key2": "second expression"}
// optionals
FILTER=An expression to filter layer
FIELDS=list of requested field separated by comma
WITH_GEOMETRY=False
"""
layer_name = params.get('LAYER', '')
if not layer_name:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'VirtualFields' REQUEST: LAYER parameter is mandatory",
400)
# get layer
layer = find_vector_layer(layer_name, project)
# layer not found
if not layer:
raise ExpressionServiceError(
"Bad request error",
"Invalid LAYER parameter for 'VirtualFields': {} provided".format(layer_name),
400)
# get virtuals
virtuals = params.get('VIRTUALS', '')
if not virtuals:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'VirtualFields' REQUEST: VIRTUALS parameter is mandatory",
400)
# try to load virtuals dict
try:
vir_json = json.loads(virtuals)
except Exception:
QgsMessageLog.logMessage(
"JSON loads virtuals '{}' exception:\n{}".format(virtuals, traceback.format_exc()),
"lizmap", Qgis.Critical)
raise ExpressionServiceError(
"Bad request error",
"Invalid 'VirtualFields' REQUEST: VIRTUALS '{}' are not well formed".format(virtuals),
400)
if not isinstance(vir_json, dict):
raise ExpressionServiceError(
"Bad request error",
"Invalid 'VirtualFields' REQUEST: VIRTUALS '{}' are not well formed".format(virtuals),
400)
# create expression context
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope(project))
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
# create distance area context
da = QgsDistanceArea()
da.setSourceCrs(layer.crs(), project.transformContext())
da.setEllipsoid(project.ellipsoid())
# parse virtuals
exp_map = {}
exp_parser_errors = []
for k, e in vir_json.items():
exp = QgsExpression(e)
exp.setGeomCalculator(da)
exp.setDistanceUnits(project.distanceUnits())
exp.setAreaUnits(project.areaUnits())
if exp.hasParserError():
exp_parser_errors.append('Error "{}": {}'.format(e, exp.parserErrorString()))
continue
if not exp.isValid():
exp_parser_errors.append('Expression not valid "{}"'.format(e))
continue
exp.prepare(exp_context)
exp_map[k] = exp
# expression parser errors found
if exp_parser_errors:
raise ExpressionServiceError(
"Bad request error",
"Invalid VIRTUALS for 'VirtualFields':\n{}".format('\n'.join(exp_parser_errors)),
400)
req = QgsFeatureRequest()
# get filter
req_filter = params.get('FILTER', '')
if req_filter:
req_exp = QgsExpression(req_filter)
req_exp.setGeomCalculator(da)
req_exp.setDistanceUnits(project.distanceUnits())
req_exp.setAreaUnits(project.areaUnits())
if req_exp.hasParserError():
raise ExpressionServiceError(
"Bad request error",
"Invalid FILTER for 'VirtualFields' Error \"{}\": {}".format(
req_filter, req_exp.parserErrorString()),
400)
if not req_exp.isValid():
raise ExpressionServiceError(
"Bad request error",
"Invalid FILTER for 'VirtualFields' Expression not valid \"{}\"".format(req_filter),
400)
req_exp.prepare(exp_context)
req = QgsFeatureRequest(req_exp, exp_context)
# With geometry
with_geom = params.get('WITH_GEOMETRY', '').lower() in ['true', '1', 't']
if not with_geom:
req.setFlags(QgsFeatureRequest.NoGeometry)
# Fields
pk_attributes = layer.primaryKeyAttributes()
attribute_list = [i for i in pk_attributes]
fields = layer.fields()
r_fields = [f.strip() for f in params.get('FIELDS', '').split(',') if f]
for f in r_fields:
attribute_list.append(fields.indexOf(f))
# response
response.setStatusCode(200)
response.setHeader("Content-Type", "application/json")
response.write('{ "type": "FeatureCollection","features":[')
response.flush()
json_exporter = QgsJsonExporter(layer)
if attribute_list:
json_exporter.setAttributes(attribute_list)
separator = ''
for feat in layer.getFeatures(req):
fid = layer_name + '.' + get_server_fid(feat, pk_attributes)
extra = {}
# Update context
exp_context.setFeature(feat)
exp_context.setFields(feat.fields())
# Evaluate expressions for virtual fields
errors = {}
for k, exp in exp_map.items():
value = exp.evaluate(exp_context)
if exp.hasEvalError():
extra[k] = None
errors[k] = exp.evalErrorString()
else:
extra[k] = json.loads(QgsJsonUtils.encodeValue(value))
errors[k] = exp.expression()
response.write(separator + json_exporter.exportFeature(feat, extra, fid))
response.flush()
separator = ',\n'
response.write(']}')
return
def processAlgorithm(self, context, feedback):
layer = QgsProcessingUtils.mapLayerFromString(
self.getParameterValue(self.INPUT_LAYER), context)
fieldName = self.getParameterValue(self.FIELD_NAME)
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
width = self.getParameterValue(self.FIELD_LENGTH)
precision = self.getParameterValue(self.FIELD_PRECISION)
newField = self.getParameterValue(self.NEW_FIELD)
formula = self.getParameterValue(self.FORMULA)
output = self.getOutputFromName(self.OUTPUT_LAYER)
fields = layer.fields()
if newField:
fields.append(QgsField(fieldName, fieldType, '', width, precision))
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs(),
context)
exp = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(layer.crs())
da.setEllipsoid(QgsProject.instance().ellipsoid())
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())
exp_context = QgsExpressionContext(
QgsExpressionContextUtils.globalProjectLayerScopes(layer))
if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: {0}').format(exp.evalErrorString()))
outFeature = QgsFeature()
outFeature.initAttributes(len(fields))
outFeature.setFields(fields)
error = ''
calculationSuccess = True
features = QgsProcessingUtils.getFeatures(layer, context)
total = 100.0 / QgsProcessingUtils.featureCount(layer, context)
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
break
else:
outFeature.setGeometry(f.geometry())
for fld in f.fields():
outFeature[fld.name()] = f[fld.name()]
outFeature[fieldName] = value
writer.addFeature(outFeature)
feedback.setProgress(int(current * total))
del writer
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation '
'string:\n{0}').format(error))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT_LAYER))
fieldName = self.getParameterValue(self.FIELD_NAME)
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
width = self.getParameterValue(self.FIELD_LENGTH)
precision = self.getParameterValue(self.FIELD_PRECISION)
newField = self.getParameterValue(self.NEW_FIELD)
formula = self.getParameterValue(self.FORMULA)
output = self.getOutputFromName(self.OUTPUT_LAYER)
if output.value == '':
ext = output.getDefaultFileExtension(self)
output.value = system.getTempFilenameInTempFolder(output.name +
'.' + ext)
fields = layer.fields()
if newField:
fields.append(QgsField(fieldName, fieldType, '', width, precision))
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs())
exp = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: %s' % exp.evalErrorString()))
# add layer to registry to fix https://issues.qgis.org/issues/17300
# it is necessary only for aggregate expressions that verify that layer
# is registered
removeRegistryAfterEvaluation = False
if not QgsMapLayerRegistry.instance().mapLayer(layer.id()):
removeRegistryAfterEvaluation = True
QgsMapLayerRegistry.instance().addMapLayer(layer,
addToLegend=False)
outFeature = QgsFeature()
outFeature.initAttributes(len(fields))
outFeature.setFields(fields)
error = ''
calculationSuccess = True
features = vector.features(layer)
total = 100.0 / len(features) if len(features) > 0 else 1
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
break
else:
outFeature.setGeometry(f.geometry())
for fld in f.fields():
outFeature[fld.name()] = f[fld.name()]
outFeature[fieldName] = value
writer.addFeature(outFeature)
progress.setPercentage(int(current * total))
del writer
# remove from registry if added for expression requirement
# see above comment about fix #17300
if removeRegistryAfterEvaluation:
QgsMapLayerRegistry.instance().removeMapLayer(layer)
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation '
'string:\n%s' % error))
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 )
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(self.getParameterValue(self.INPUT_LAYER))
fieldName = self.getParameterValue(self.FIELD_NAME)
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
width = self.getParameterValue(self.FIELD_LENGTH)
precision = self.getParameterValue(self.FIELD_PRECISION)
newField = self.getParameterValue(self.NEW_FIELD)
formula = self.getParameterValue(self.FORMULA)
output = self.getOutputFromName(self.OUTPUT_LAYER)
if output.value == '':
ext = output.getDefaultFileExtension(self)
output.value = system.getTempFilenameInTempFolder(
output.name + '.' + ext)
fields = layer.fields()
if newField:
fields.append(QgsField(fieldName, fieldType, '', width, precision))
writer = output.getVectorWriter(fields, layer.wkbType(),
layer.crs())
exp = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: %s' % exp.evalErrorString()))
# add layer to registry to fix https://issues.qgis.org/issues/17300
# it is necessary only for aggregate expressions that verify that layer
# is registered
removeRegistryAfterEvaluation = False
if not QgsMapLayerRegistry.instance().mapLayer(layer.id()):
removeRegistryAfterEvaluation = True
QgsMapLayerRegistry.instance().addMapLayer(layer, addToLegend=False)
outFeature = QgsFeature()
outFeature.initAttributes(len(fields))
outFeature.setFields(fields)
error = ''
calculationSuccess = True
features = vector.features(layer)
total = 100.0 / len(features) if len(features) > 0 else 1
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
break
else:
outFeature.setGeometry(f.geometry())
for fld in f.fields():
outFeature[fld.name()] = f[fld.name()]
outFeature[fieldName] = value
writer.addFeature(outFeature)
progress.setPercentage(int(current * total))
del writer
# remove from registry if added for expression requirement
# see above comment about fix #17300
if removeRegistryAfterEvaluation:
QgsMapLayerRegistry.instance().removeMapLayer(layer)
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation '
'string:\n%s' % error))
def processAlgorithm(self, parameters, context, feedback):
layer = QgsProcessingUtils.mapLayerFromString(self.getParameterValue(self.INPUT_LAYER), context)
fieldName = self.getParameterValue(self.FIELD_NAME)
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
width = self.getParameterValue(self.FIELD_LENGTH)
precision = self.getParameterValue(self.FIELD_PRECISION)
newField = self.getParameterValue(self.NEW_FIELD)
formula = self.getParameterValue(self.FORMULA)
output = self.getOutputFromName(self.OUTPUT_LAYER)
fields = layer.fields()
if newField:
fields.append(QgsField(fieldName, fieldType, '', width, precision))
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs(), context)
exp = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(layer.crs())
da.setEllipsoid(QgsProject.instance().ellipsoid())
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())
exp_context = QgsExpressionContext(QgsExpressionContextUtils.globalProjectLayerScopes(layer))
if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: {0}').format(exp.evalErrorString()))
outFeature = QgsFeature()
outFeature.initAttributes(len(fields))
outFeature.setFields(fields)
error = ''
calculationSuccess = True
features = QgsProcessingUtils.getFeatures(layer, context)
total = 100.0 / layer.featureCount() if layer.featureCount() else 0
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
break
else:
outFeature.setGeometry(f.geometry())
for fld in f.fields():
outFeature[fld.name()] = f[fld.name()]
outFeature[fieldName] = value
writer.addFeature(outFeature, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
del writer
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation '
'string:\n{0}').format(error))
def processAlgorithm(self, parameters, context, feedback):
layer = self.getParameterValue(self.INPUT_LAYER)
mapping = self.getParameterValue(self.FIELDS_MAPPING)
output = self.getOutputFromName(self.OUTPUT_LAYER)
layer = QgsProcessingUtils.mapLayerFromString(layer, context)
fields = QgsFields()
expressions = []
da = QgsDistanceArea()
da.setSourceCrs(layer.crs())
da.setEllipsoid(context.project().ellipsoid())
exp_context = layer.createExpressionContext()
for field_def in mapping:
fields.append(QgsField(field_def['name'],
field_def['type'],
field_def['length'],
field_def['precision']))
expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(context.project().distanceUnits())
expression.setAreaUnits(context.project().areaUnits())
expression.prepare(exp_context)
if expression.hasParserError():
raise GeoAlgorithmExecutionException(
self.tr(u'Parser error in expression "{}": {}')
.format(str(expression.expression()),
str(expression.parserErrorString())))
expressions.append(expression)
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs(), context)
# Create output vector layer with new attributes
error_exp = None
inFeat = QgsFeature()
outFeat = QgsFeature()
features = QgsProcessingUtils.getFeatures(layer, context)
count = QgsProcessingUtils.featureCount(layer, context)
if count > 0:
total = 100.0 / count
for current, inFeat in enumerate(features):
rownum = current + 1
geometry = inFeat.geometry()
outFeat.setGeometry(geometry)
attrs = []
for i in range(0, len(mapping)):
field_def = mapping[i]
expression = expressions[i]
exp_context.setFeature(inFeat)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
error_exp = expression
break
attrs.append(value)
outFeat.setAttributes(attrs)
writer.addFeature(outFeat, QgsFeatureSink.FastInsert)
feedback.setProgress(int(current * total))
else:
feedback.setProgress(100)
del writer
if error_exp is not None:
raise GeoAlgorithmExecutionException(
self.tr(u'Evaluation error in expression "{}": {}')
.format(str(error_exp.expression()),
str(error_exp.parserErrorString())))
def processAlgorithm(self, progress):
layer = dataobjects.getObjectFromUri(
self.getParameterValue(self.INPUT_LAYER))
fieldName = self.getParameterValue(self.FIELD_NAME)
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
width = self.getParameterValue(self.FIELD_LENGTH)
precision = self.getParameterValue(self.FIELD_PRECISION)
newField = self.getParameterValue(self.NEW_FIELD)
formula = self.getParameterValue(self.FORMULA)
output = self.getOutputFromName(self.OUTPUT_LAYER)
fields = layer.fields()
if newField:
fields.append(QgsField(fieldName, fieldType, '', width, precision))
writer = output.getVectorWriter(fields, layer.wkbType(), layer.crs())
exp = QgsExpression(formula)
da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: %s' % exp.evalErrorString()))
outFeature = QgsFeature()
outFeature.initAttributes(len(fields))
outFeature.setFields(fields)
error = ''
calculationSuccess = True
features = vector.features(layer)
total = 100.0 / len(features)
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
break
else:
outFeature.setGeometry(f.geometry())
for fld in f.fields():
outFeature[fld.name()] = f[fld.name()]
outFeature[fieldName] = value
writer.addFeature(outFeature)
progress.setPercentage(int(current * total))
del writer
if not calculationSuccess:
raise GeoAlgorithmExecutionException(
self.tr('An error occurred while evaluating the calculation '
'string:\n%s' % error))
def evaluate(params: Dict[str, str], response: QgsServerResponse, project: QgsProject) -> None:
""" Evaluate expressions against layer or features
In parameters:
LAYER=wms-layer-name
EXPRESSION=An expression to evaluate
or
EXPRESSIONS=["first expression", "second expression"]
or
EXPRESSIONS={"key1": "first expression", "key2": "second expression"}
// optionals
FEATURE={"type": "Feature", "geometry": {}, "properties": {}}
or
FEATURES=[{"type": "Feature", "geometry": {}, "properties": {}}, {"type": "Feature", "geometry": {},
"properties": {}}]
FORM_SCOPE=boolean to add formScope based on provided features
"""
layername = params.get('LAYER', '')
if not layername:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'Evaluate' REQUEST: LAYER parameter is mandatory",
400)
# get layer
layer = find_vector_layer(layername, project)
# layer not found
if not layer:
raise ExpressionServiceError(
"Bad request error",
"Invalid LAYER parameter for 'Evaluate': {} provided".format(layername),
400)
# get expressions
expressions = params.get('EXPRESSIONS', '')
if not expressions:
expression = params.get('EXPRESSION', '')
if not expression:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'Evaluate' REQUEST: EXPRESSION or EXPRESSIONS parameter is mandatory",
400)
expressions = '["{}"]'.format(expression)
# try to load expressions list or dict
try:
exp_json = json.loads(expressions)
except Exception:
QgsMessageLog.logMessage(
"JSON loads expressions '{}' exception:\n{}".format(expressions, traceback.format_exc()),
"lizmap", Qgis.Critical)
raise ExpressionServiceError(
"Bad request error",
"Invalid 'Evaluate' REQUEST: EXPRESSIONS '{}' are not well formed".format(expressions),
400)
# create expression context
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope(project))
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))
# create distance area context
da = QgsDistanceArea()
da.setSourceCrs(layer.crs(), project.transformContext())
da.setEllipsoid(project.ellipsoid())
# parse expressions
exp_map = {}
exp_parser_errors = []
exp_items = []
if isinstance(exp_json, list):
exp_items = enumerate(exp_json)
elif isinstance(exp_json, dict):
exp_items = exp_json.items()
for k, e in exp_items:
exp = QgsExpression(e)
exp.setGeomCalculator(da)
exp.setDistanceUnits(project.distanceUnits())
exp.setAreaUnits(project.areaUnits())
if exp.hasParserError():
exp_parser_errors.append('Error "{}": {}'.format(e, exp.parserErrorString()))
continue
if not exp.isValid():
exp_parser_errors.append('Expression not valid "{}"'.format(e))
continue
exp.prepare(exp_context)
exp_map[k] = exp
# expression parser errors found
if exp_parser_errors:
raise ExpressionServiceError(
"Bad request error",
"Invalid EXPRESSIONS for 'Evaluate':\n{}".format('\n'.join(exp_parser_errors)),
400)
# get features
features = params.get('FEATURES', '')
if not features:
feature = params.get('FEATURE', '')
if feature:
features = '[' + feature + ']'
# create the body
body = {
'status': 'success',
'results': [],
'errors': [],
'features': 0
}
# without features just evaluate expression with layer context
if not features:
result = {}
error = {}
for k, exp in exp_map.items():
value = exp.evaluate(exp_context)
if exp.hasEvalError():
result[k] = None
error[k] = exp.evalErrorString()
else:
result[k] = json.loads(QgsJsonUtils.encodeValue(value))
body['results'].append(result)
body['errors'].append(error)
write_json_response(body, response)
return
# Check features
try:
geojson = json.loads(features)
except Exception:
QgsMessageLog.logMessage(
"JSON loads features '{}' exception:\n{}".format(features, traceback.format_exc()),
"lizmap", Qgis.Critical)
raise ExpressionServiceError(
"Bad request error",
"Invalid 'Evaluate' REQUEST: FEATURES '{}' are not well formed".format(features),
400)
if not geojson or not isinstance(geojson, list) or len(geojson) == 0:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'Evaluate' REQUEST: FEATURES '{}' are not well formed".format(features),
400)
if 'type' not in geojson[0] or geojson[0]['type'] != 'Feature':
raise ExpressionServiceError(
"Bad request error",
("Invalid 'Evaluate' REQUEST: FEATURES '{}' are not well formed: type not defined or not "
"Feature.").format(features),
400)
# try to load features
# read fields
feature_fields = QgsJsonUtils.stringToFields(
'{ "type": "FeatureCollection","features":' + features + '}',
QTextCodec.codecForName("UTF-8"))
# read features
feature_list = QgsJsonUtils.stringToFeatureList(
'{ "type": "FeatureCollection","features":' + features + '}',
feature_fields,
QTextCodec.codecForName("UTF-8"))
# features not well formed
if not feature_list:
raise ExpressionServiceError(
"Bad request error",
"Invalid FEATURES for 'Evaluate': not GeoJSON features array provided\n{}".format(features),
400)
# Extend layer fields with this provided in GeoJSON Features
feat_fields = QgsFields(layer.fields())
feat_fields.extend(feature_fields)
# form scope
add_form_scope = params.get('FORM_SCOPE', '').lower() in ['true', '1', 't']
# loop through provided features to evaluate expressions
for f in feature_list:
# clone the features with all attributes
# those defined in layer + fields from GeoJSON Features
feat = QgsFeature(feat_fields)
feat.setGeometry(f.geometry())
for field in f.fields():
fname = field.name()
if feat_fields.indexOf(fname) != -1:
feat.setAttribute(fname, f[fname])
# Add form scope to expression context
if add_form_scope:
exp_context.appendScope(QgsExpressionContextUtils.formScope(feat))
exp_context.setFeature(feat)
exp_context.setFields(feat.fields())
# Evaluate expressions with the new feature
result = {}
error = {}
for k, exp in exp_map.items():
if add_form_scope:
# need to prepare the expression because the context has been updated with a new scope
exp.prepare(exp_context)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
result[k] = None
error[k] = exp.evalErrorString()
else:
result[k] = json.loads(QgsJsonUtils.encodeValue(value))
error[k] = exp.expression()
body['results'].append(result)
body['errors'].append(error)
write_json_response(body, response)
return
