def testReferencedAttributeIndexesNonExistingField(self):
e = QgsExpression()
e.setExpression("foo = 1")
self.assertTrue(e.isValid())
self.assertEqual(len(e.referencedAttributeIndexes(QgsFields())), 0)
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
group_field_name = self.parameterAsString(parameters, self.GROUP_FIELD, context)
order_field_name = self.parameterAsString(parameters, self.ORDER_FIELD, context)
date_format = self.parameterAsString(parameters, self.DATE_FORMAT, context)
mvalue_exp = self.parameterAsExpression(parameters, self.MVALUE_EXPRESSION, context)
text_dir = self.parameterAsString(parameters, self.OUTPUT_TEXT_DIR, context)
QgsMessageLog.logMessage("-"*80)
QgsMessageLog.logMessage(str(mvalue_exp))
QgsMessageLog.logMessage(mvalue_exp.__class__.__name__)
# instantiate the expression if mvalue is set
if mvalue_exp:
expression = QgsExpression(mvalue_exp)
expression_ctx = self.createExpressionContext(parameters, context)
expression.prepare(expression_ctx)
else:
expression = None
group_field_index = source.fields().lookupField(group_field_name)
order_field_index = source.fields().lookupField(order_field_name)
if group_field_index >= 0:
group_field_def = source.fields().at(group_field_index)
else:
group_field_def = None
order_field_def = source.fields().at(order_field_index)
fields = QgsFields()
if group_field_def is not None:
fields.append(group_field_def)
begin_field = QgsField(order_field_def)
begin_field.setName('begin')
fields.append(begin_field)
end_field = QgsField(order_field_def)
end_field.setName('end')
fields.append(end_field)
output_wkb = QgsWkbTypes.LineString
if QgsWkbTypes.hasM(source.wkbType()) or mvalue_exp:
output_wkb = QgsWkbTypes.addM(output_wkb)
if QgsWkbTypes.hasZ(source.wkbType()):
output_wkb = QgsWkbTypes.addZ(output_wkb)
(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
fields, output_wkb, source.sourceCrs())
if sink is None:
raise QgsProcessingException(self.invalidSinkError(parameters, self.OUTPUT))
points = dict()
referencedColumns = expression.referencedAttributeIndexes(source.fields()) if expression else [group_field_index, order_field_index]
features = source.getFeatures(QgsFeatureRequest().setSubsetOfAttributes(referencedColumns), QgsProcessingFeatureSource.FlagSkipGeometryValidityChecks)
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, f in enumerate(features):
if feedback.isCanceled():
break
if not f.hasGeometry():
continue
point = f.geometry().constGet().clone()
if group_field_index >= 0:
group = f.attributes()[group_field_index]
else:
group = 1
order = f.attributes()[order_field_index]
if date_format != '':
order = datetime.strptime(str(order), date_format)
if group in points:
points[group].append((order, point, f))
else:
points[group] = [(order, point, f)]
feedback.setProgress(int(current * total))
feedback.setProgress(0)
da = QgsDistanceArea()
da.setSourceCrs(source.sourceCrs(), context.transformContext())
da.setEllipsoid(context.project().ellipsoid())
current = 0
total = 100.0 / len(points) if points else 1
for group, vertices in list(points.items()):
if feedback.isCanceled():
break
vertices.sort(key=lambda x: (x[0] is None, x[0]))
f = QgsFeature()
attributes = []
if group_field_index >= 0:
attributes.append(group)
attributes.extend([vertices[0][0], vertices[-1][0]])
f.setAttributes(attributes)
line = [node[1] for node in vertices]
if text_dir:
fileName = os.path.join(text_dir, '%s.txt' % group)
with open(fileName, 'w') as fl:
fl.write('angle=Azimuth\n')
fl.write('heading=Coordinate_System\n')
fl.write('dist_units=Default\n')
for i in range(len(line)):
if i == 0:
fl.write('startAt=%f;%f;90\n' % (line[i].x(), line[i].y()))
fl.write('survey=Polygonal\n')
fl.write('[data]\n')
else:
angle = line[i - 1].azimuth(line[i])
distance = da.measureLine(QgsPointXY(line[i - 1]), QgsPointXY(line[i]))
fl.write('%f;%f;90\n' % (angle, distance))
linestring = QgsLineString(line)
if mvalue_exp:
linestring.addMValue(0)
for i, node in enumerate(vertices):
QgsMessageLog.logMessage(node[2].__class__.__name__)
expression_ctx.setFeature(node[2])
mvalue = expression.evaluate(expression_ctx)
if expression.hasEvalError():
raise QgsProcessingException(
self.tr('Evaluation error: {0}').format(expression.evalErrorString()))
QgsMessageLog.logMessage("evaluating mvalue at {} to {} {}".format(i, mvalue, mvalue.__class__))
# mvalue = 12 # TODO : remove
QgsMessageLog.logMessage("setting mvalue at {} to {} {}".format(i, mvalue, mvalue.__class__))
linestring.setMAt(i, mvalue)
# test = linestring.mAt(i) # TODO : remove
# QgsMessageLog.logMessage("mvalue at {} is {} {}".format(i, test, test.__class__)) # TODO : remove
f.setGeometry(QgsGeometry(linestring))
sink.addFeature(f, QgsFeatureSink.FastInsert)
current += 1
feedback.setProgress(int(current * total))
return {self.OUTPUT: dest_id}
