QGIS/python/plugins/processing/algs/qgis/FieldPyculator.py
2024-11-29 15:38:02 +01:00

294 lines
10 KiB
Python

"""
***************************************************************************
FieldPyculator.py
---------------------
Date : August 2012
Copyright : (C) 2012 by Victor Olaya
Email : volayaf at gmail dot com
***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************
"""
__author__ = "Victor Olaya & NextGIS"
__date__ = "August 2012"
__copyright__ = "(C) 2012, Victor Olaya & NextGIS"
import sys
from qgis.PyQt.QtCore import QMetaType
from qgis.core import (
Qgis,
QgsProcessingException,
QgsField,
QgsFields,
QgsFeatureSink,
QgsProcessing,
QgsProcessingParameterFeatureSource,
QgsProcessingParameterString,
QgsProcessingParameterEnum,
QgsProcessingParameterNumber,
QgsProcessingParameterFeatureSink,
QgsVariantUtils,
)
from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
class FieldsPyculator(QgisAlgorithm):
INPUT = "INPUT"
FIELD_NAME = "FIELD_NAME"
FIELD_TYPE = "FIELD_TYPE"
FIELD_LENGTH = "FIELD_LENGTH"
FIELD_PRECISION = "FIELD_PRECISION"
GLOBAL = "GLOBAL"
FORMULA = "FORMULA"
OUTPUT = "OUTPUT"
RESULT_VAR_NAME = "value"
def flags(self):
# This algorithm represents a security risk, due to the use
# of the Python "exec" function
return super().flags() | Qgis.ProcessingAlgorithmFlag.SecurityRisk
def group(self):
return self.tr("Vector table")
def groupId(self):
return "vectortable"
def __init__(self):
super().__init__()
def initAlgorithm(self, config=None):
self.addParameter(
QgsProcessingParameterFeatureSource(
self.INPUT,
self.tr("Input layer"),
types=[QgsProcessing.SourceType.TypeVector],
)
)
self.addParameter(
QgsProcessingParameterString(
self.FIELD_NAME, self.tr("Result field name"), defaultValue="NewField"
)
)
types = [
(QMetaType.Type.Int, QMetaType.Type.UnknownType),
(QMetaType.Type.Double, QMetaType.Type.UnknownType),
(QMetaType.Type.QString, QMetaType.Type.UnknownType),
(QMetaType.Type.Bool, QMetaType.Type.UnknownType),
(QMetaType.Type.QDate, QMetaType.Type.UnknownType),
(QMetaType.Type.QTime, QMetaType.Type.UnknownType),
(QMetaType.Type.QDateTime, QMetaType.Type.UnknownType),
(QMetaType.Type.QByteArray, QMetaType.Type.UnknownType),
(QMetaType.Type.QStringList, QMetaType.Type.QString),
(QMetaType.Type.QVariantList, QMetaType.Type.Int),
(QMetaType.Type.QVariantList, QMetaType.Type.Double),
]
type_names = []
type_icons = []
for type_name, subtype_name in types:
type_names.append(
QgsVariantUtils.typeToDisplayString(type_name, subtype_name)
)
type_icons.append(QgsFields.iconForFieldType(type_name, subtype_name))
param = QgsProcessingParameterEnum(
"FIELD_TYPE", "Field type", options=type_names
)
param.setMetadata({"widget_wrapper": {"icons": type_icons}})
self.addParameter(param)
self.addParameter(
QgsProcessingParameterNumber(
self.FIELD_LENGTH, self.tr("Field length"), minValue=0, defaultValue=10
)
)
self.addParameter(
QgsProcessingParameterNumber(
self.FIELD_PRECISION,
self.tr("Field precision"),
minValue=0,
maxValue=15,
defaultValue=3,
)
)
self.addParameter(
QgsProcessingParameterString(
self.GLOBAL, self.tr("Global expression"), multiLine=True, optional=True
)
)
self.addParameter(
QgsProcessingParameterString(
self.FORMULA,
self.tr("Formula"),
defaultValue="value = ",
multiLine=True,
)
)
self.addParameter(
QgsProcessingParameterFeatureSink(self.OUTPUT, self.tr("Calculated"))
)
def name(self):
return "advancedpythonfieldcalculator"
def displayName(self):
return self.tr("Advanced Python field calculator")
def processAlgorithm(self, parameters, context, feedback):
source = self.parameterAsSource(parameters, self.INPUT, context)
if source is None:
raise QgsProcessingException(
self.invalidSourceError(parameters, self.INPUT)
)
field_name = self.parameterAsString(parameters, self.FIELD_NAME, context)
field_type = QMetaType.Type.UnknownType
field_sub_type = QMetaType.Type.UnknownType
field_type_parameter = self.parameterAsEnum(
parameters, self.FIELD_TYPE, context
)
if field_type_parameter == 0: # Integer
field_type = QMetaType.Type.Int
elif field_type_parameter == 1: # Float
field_type = QMetaType.Type.Double
elif field_type_parameter == 2: # String
field_type = QMetaType.Type.QString
elif field_type_parameter == 3: # Boolean
field_type = QMetaType.Type.Bool
elif field_type_parameter == 4: # Date
field_type = QMetaType.Type.QDate
elif field_type_parameter == 5: # Time
field_type = QMetaType.Type.QTime
elif field_type_parameter == 6: # DateTime
field_type = QMetaType.Type.QDateTime
elif field_type_parameter == 7: # Binary
field_type = QMetaType.Type.QByteArray
elif field_type_parameter == 8: # StringList
field_type = QMetaType.Type.QStringList
field_sub_type = QMetaType.Type.QString
elif field_type_parameter == 9: # IntegerList
field_type = QMetaType.Type.QVariantList
field_sub_type = QMetaType.Type.Int
elif field_type_parameter == 10: # DoubleList
field_type = QMetaType.Type.QVariantList
field_sub_type = QMetaType.Type.Double
width = self.parameterAsInt(parameters, self.FIELD_LENGTH, context)
precision = self.parameterAsInt(parameters, self.FIELD_PRECISION, context)
code = self.parameterAsString(parameters, self.FORMULA, context)
globalExpression = self.parameterAsString(parameters, self.GLOBAL, context)
fields = source.fields()
field = QgsField(
field_name, field_type, "", width, precision, "", field_sub_type
)
fields.append(field)
new_ns = {}
(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))
# Run global code
if globalExpression.strip() != "":
try:
bytecode = compile(globalExpression, "<string>", "exec")
exec(bytecode, new_ns)
except:
raise QgsProcessingException(
self.tr(
"FieldPyculator code execute error. Global code block can't be executed!\n{0}\n{1}"
).format(str(sys.exc_info()[0].__name__), str(sys.exc_info()[1]))
)
# Replace all fields tags
fields = source.fields()
for num, field in enumerate(fields):
field_name = str(field.name())
replval = "__attr[" + str(num) + "]"
code = code.replace("<" + field_name + ">", replval)
# Replace all special vars
code = code.replace("$id", "__id")
code = code.replace("$geom", "__geom")
need_id = code.find("__id") != -1
need_geom = code.find("__geom") != -1
need_attrs = code.find("__attr") != -1
# Compile
try:
bytecode = compile(code, "<string>", "exec")
except:
raise QgsProcessingException(
self.tr(
"FieldPyculator code execute error. Field code block can't be executed!\n{0}\n{1}"
).format(str(sys.exc_info()[0].__name__), str(sys.exc_info()[1]))
)
# Run
features = source.getFeatures()
total = 100.0 / source.featureCount() if source.featureCount() else 0
for current, feat in enumerate(features):
if feedback.isCanceled():
break
feedback.setProgress(int(current * total))
attrs = feat.attributes()
feat_id = feat.id()
# Add needed vars
if need_id:
new_ns["__id"] = feat_id
if need_geom:
geom = feat.geometry()
new_ns["__geom"] = geom
if need_attrs:
pyattrs = [a for a in attrs]
new_ns["__attr"] = pyattrs
# Clear old result
if self.RESULT_VAR_NAME in new_ns:
del new_ns[self.RESULT_VAR_NAME]
# Exec
exec(bytecode, new_ns)
# Check result
if self.RESULT_VAR_NAME not in new_ns:
raise QgsProcessingException(
self.tr(
"FieldPyculator code execute error\n"
"Field code block does not return '{0}' variable! "
"Please declare this variable in your code!"
).format(self.RESULT_VAR_NAME)
)
# Write feature
attrs.append(new_ns[self.RESULT_VAR_NAME])
feat.setAttributes(attrs)
sink.addFeature(feat, QgsFeatureSink.Flag.FastInsert)
sink.finalize()
return {self.OUTPUT: dest_id}
def checkParameterValues(self, parameters, context):
# TODO check that formula is correct and fields exist
return super().checkParameterValues(parameters, context)