def apply_filter(self, request, metadata_layer, qgis_feature_request,
view):
if request.data and request.data.get('expression'):
qgis_feature_request.combineFilterExpression(
request.data.get('expression'))
if request.data.get('form_data') and request.data.get(
'qgs_layer_id'):
try:
project = Layer.objects.get(
pk=metadata_layer.layer_id).project
layer = Layer.objects.get(
project=project,
qgs_layer_id=request.data.get('qgs_layer_id'))
fields = layer.qgis_layer.fields()
form_data = request.data.get('form_data')
form_feature = QgsJsonUtils.stringToFeatureList(
json.dumps(form_data), fields, None)[0]
for k, v in form_data['properties'].items():
form_feature.setAttribute(k, v)
qgis_feature_request.expressionContext().appendScope(
QgsExpressionContextUtils.formScope(form_feature))
except:
raise Exception("Layer or project could not be found!")
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 replace_expression_text(params: Dict[str, str], response: QgsServerResponse, project: QgsProject) -> None:
""" Replace expression texts against layer or features
In parameters:
LAYER=wms-layer-name
STRING=A string with expression between [% and %]
or
STRINGS=["first string with expression", "second string with expression"]
or
STRINGS={"key1": "first string with expression", "key2": "second string with 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 'ReplaceExpressionText' 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 'ReplaceExpressionText': {} provided".format(layername),
400)
# get strings
strings = params.get('STRINGS', '')
if not strings:
the_string = params.get('STRING', '')
if not the_string:
raise ExpressionServiceError(
"Bad request error",
"Invalid 'ReplaceExpressionText' REQUEST: STRING or STRINGS parameter is mandatory",
400)
strings = '["{}"]'.format(the_string)
# try to load expressions list or dict
try:
str_json = json.loads(strings)
except Exception:
QgsMessageLog.logMessage(
"JSON loads strings '{}' exception:\n{}".format(strings, traceback.format_exc()),
"lizmap", Qgis.Critical)
raise ExpressionServiceError(
"Bad request error",
"Invalid 'ReplaceExpressionText' REQUEST: STRINGS '{}' are not well formed".format(strings),
400)
# get features
features = params.get('FEATURES', '')
if not features:
feature = params.get('FEATURE', '')
if feature:
features = '[' + feature + ']'
# 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())
# organized strings
str_map = {}
str_items = []
if isinstance(str_json, list):
str_items = enumerate(str_json)
elif isinstance(str_json, dict):
str_items = str_json.items()
for k, s in str_items:
str_map[k] = s
# create the body
body = {
'status': 'success',
'results': [],
'errors': [],
'features': 0
}
# without features just replace expression string with layer context
if not features:
result = {}
for k, s in str_map.items():
value = QgsExpression.replaceExpressionText(s, exp_context, da)
result[k] = json.loads(QgsJsonUtils.encodeValue(value))
body['results'].append(result)
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 'ReplaceExpressionText': 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 replace expression strings
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():
field_name = field.name()
if feat_fields.indexOf(field_name) != -1:
feat.setAttribute(field_name, f[field_name])
# 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())
# replace expression strings with the new feature
result = {}
for k, s in str_map.items():
value = QgsExpression.replaceExpressionText(s, exp_context, da)
result[k] = json.loads(QgsJsonUtils.encodeValue(value))
body['results'].append(result)
write_json_response(body, response)
return
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
def expression_eval(expression_text,
project_id=None,
qgs_layer_id=None,
form_data=None,
formatter=0):
"""Evaluates a QgsExpression and returns the result
:param expression_text: The QgsExpression text
:type expression_text: str
:param project_id: ID of the qdjango project, defaults to None
:type project_id: int, optional
:param qgs_layer_id: ID of the QGIS Layer, defaults to None
:type qgslayer_id: str, optional
:param form_data: A dictionary that maps to a GeoJSON representation of the feature currently edited in the form
:type form_data: dict, optional
:param formatter: Indicate if form_data values contains formatter values or original features value.
:type formatter: int, optional
"""
expression = QgsExpression(expression_text)
expression_context = QgsExpressionContext()
layer = None
for func_name in expression.referencedFunctions():
if func_name in FORBIDDEN_FUNCTIONS:
raise ExpressionForbiddenError(
_('Function "{}" is not allowed for security reasons!').format(
func_name))
for var_name in expression.referencedVariables():
if var_name in FORBIDDEN_VARIABLES:
raise ExpressionForbiddenError(
_('Variable "{}" is not allowed for security reasons!').format(
var_name))
if project_id is not None:
try:
project = Project.objects.get(pk=project_id)
if qgs_layer_id is not None:
try:
layer = project.layer_set.get(qgs_layer_id=qgs_layer_id)
except Layer.DoesNotExist:
raise ExpressionLayerError(
_('QGIS layer with id "{}" could not be found!').
format(qgs_layer_id))
expression_contex = QgsExpressionContextUtils.globalProjectLayerScopes(
layer.qgis_layer)
else:
expression_contex = QgsExpressionContextUtils.globalScope()
expression_context.appendScope(
QgsExpressionContextUtils.projectScope(
project.qgis_project))
except Project.DoesNotExist:
raise ExpressionProjectError(
_('QDjango project with id "{}" could not be found!').format(
project_id))
else:
expression_contex = QgsExpressionContextUtils.globalScope()
if form_data is not None:
if layer is None:
raise ExpressionLayerError(
_('A valid QGIS layer is required to process form data!'))
try:
# Case by formatter
# formatter == 1 : get featureid from layer, usually must be used with formatter form_data
# formatter == 0 : default behavior
if formatter == 0:
fields = layer.qgis_layer.fields()
form_feature = QgsJsonUtils.stringToFeatureList(
json.dumps(form_data), fields, None)[0]
# Set attributes manually because QgsJsonUtils does not respect order
for k, v in form_data['properties'].items():
form_feature.setAttribute(k, v)
else:
qgis_feature_request = QgsFeatureRequest()
exp = expression_from_server_fids(
[form_data['id']], layer.qgis_layer.dataProvider())
qgis_feature_request.combineFilterExpression(exp)
form_feature = get_qgis_features(layer.qgis_layer,
qgis_feature_request)[0]
expression_context.appendScope(
QgsExpressionContextUtils.formScope(form_feature))
expression_context.setFeature(form_feature)
except:
raise ExpressionFormDataError()
valid, errors = expression.checkExpression(expression_text,
expression_context)
if not valid:
raise ExpressionParseError(errors)
result = expression.evaluate(expression_context)
if expression.hasEvalError():
raise ExpressionEvalError(expression.evalErrorString())
return result
