QGIS/python/plugins/processing/algs/qgis/FieldPyculator.py
2024-01-19 19:44:48 +10:00

236 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 QVariant
from qgis.core import (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'
TYPES = [QVariant.LongLong, QVariant.Double, QVariant.String]
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 = [(QVariant.Int, QVariant.Invalid),
(QVariant.Double, QVariant.Invalid),
(QVariant.String, QVariant.Invalid),
(QVariant.Bool, QVariant.Invalid),
(QVariant.Date, QVariant.Invalid),
(QVariant.Time, QVariant.Invalid),
(QVariant.DateTime, QVariant.Invalid),
(QVariant.ByteArray, QVariant.Invalid),
(QVariant.StringList, QVariant.String),
(QVariant.List, QVariant.Int),
(QVariant.List, QVariant.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 = QVariant.Invalid
field_sub_type = QVariant.Invalid
field_type_parameter = self.parameterAsEnum(parameters, self.FIELD_TYPE, context)
if field_type_parameter == 0: # Integer
field_type = QVariant.Int
elif field_type_parameter == 1: # Float
field_type = QVariant.Double
elif field_type_parameter == 2: # String
field_type = QVariant.String
elif field_type_parameter == 3: # Boolean
field_type = QVariant.Bool
elif field_type_parameter == 4: # Date
field_type = QVariant.Date
elif field_type_parameter == 5: # Time
field_type = QVariant.Time
elif field_type_parameter == 6: # DateTime
field_type = QVariant.DateTime
elif field_type_parameter == 7: # Binary
field_type = QVariant.ByteArray
elif field_type_parameter == 8: # StringList
field_type = QVariant.StringList
field_sub_type = QVariant.String
elif field_type_parameter == 9: # IntegerList
field_type = QVariant.List
field_sub_type = QVariant.Int
elif field_type_parameter == 10: # DoubleList
field_type = QVariant.List
field_sub_type = QVariant.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)
return {self.OUTPUT: dest_id}
def checkParameterValues(self, parameters, context):
# TODO check that formula is correct and fields exist
return super().checkParameterValues(parameters, context)