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5339d62715
Include descriptive text with the specified parameter value in error, and always check that sources were loaded to avoid raw Python exceptions when they are not
192 lines
7.7 KiB
Python
192 lines
7.7 KiB
Python
# -*- coding: utf-8 -*-
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"""
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***************************************************************************
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FieldPyculator.py
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---------------------
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Date : August 2012
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Copyright : (C) 2012 by Victor Olaya
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Email : volayaf at gmail dot com
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***************************************************************************
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* *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* *
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***************************************************************************
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"""
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__author__ = 'Victor Olaya & NextGIS'
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__date__ = 'August 2012'
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__copyright__ = '(C) 2012, Victor Olaya & NextGIS'
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# This will get replaced with a git SHA1 when you do a git archive
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__revision__ = '$Format:%H$'
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import sys
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from qgis.PyQt.QtCore import QVariant
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from qgis.core import (QgsProcessingException,
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QgsField,
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QgsFeatureSink,
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QgsProcessingParameterFeatureSource,
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QgsProcessingParameterString,
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QgsProcessingParameterEnum,
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QgsProcessingParameterNumber,
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QgsProcessingParameterFeatureSink)
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from processing.algs.qgis.QgisAlgorithm import QgisAlgorithm
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class FieldsPyculator(QgisAlgorithm):
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INPUT = 'INPUT'
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FIELD_NAME = 'FIELD_NAME'
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FIELD_TYPE = 'FIELD_TYPE'
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FIELD_LENGTH = 'FIELD_LENGTH'
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FIELD_PRECISION = 'FIELD_PRECISION'
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GLOBAL = 'GLOBAL'
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FORMULA = 'FORMULA'
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OUTPUT = 'OUTPUT'
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RESULT_VAR_NAME = 'value'
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TYPES = [QVariant.LongLong, QVariant.Double, QVariant.String]
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def group(self):
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return self.tr('Vector table')
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def groupId(self):
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return 'vectortable'
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def __init__(self):
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super().__init__()
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def initAlgorithm(self, config=None):
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self.type_names = [self.tr('Integer'),
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self.tr('Float'),
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self.tr('String')]
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self.addParameter(QgsProcessingParameterFeatureSource(self.INPUT, self.tr('Input layer')))
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self.addParameter(QgsProcessingParameterString(self.FIELD_NAME,
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self.tr('Result field name'), defaultValue='NewField'))
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self.addParameter(QgsProcessingParameterEnum(self.FIELD_TYPE,
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self.tr('Field type'), options=self.type_names))
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self.addParameter(QgsProcessingParameterNumber(self.FIELD_LENGTH,
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self.tr('Field length'), minValue=1, maxValue=255, defaultValue=10))
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self.addParameter(QgsProcessingParameterNumber(self.FIELD_PRECISION,
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self.tr('Field precision'), minValue=0, maxValue=15, defaultValue=3))
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self.addParameter(QgsProcessingParameterString(self.GLOBAL,
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self.tr('Global expression'), multiLine=True, optional=True))
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self.addParameter(QgsProcessingParameterString(self.FORMULA,
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self.tr('Formula'), defaultValue='value = ', multiLine=True))
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self.addParameter(QgsProcessingParameterFeatureSink(self.OUTPUT,
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self.tr('Calculated')))
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def name(self):
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return 'advancedpythonfieldcalculator'
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def displayName(self):
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return self.tr('Advanced Python field calculator')
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def processAlgorithm(self, parameters, context, feedback):
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source = self.parameterAsSource(parameters, self.INPUT, context)
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if source is None:
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raise QgsProcessingException(self.invalidSourceError(parameters, self.INPUT))
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field_name = self.parameterAsString(parameters, self.FIELD_NAME, context)
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field_type = self.TYPES[self.parameterAsEnum(parameters, self.FIELD_TYPE, context)]
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width = self.parameterAsInt(parameters, self.FIELD_LENGTH, context)
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precision = self.parameterAsInt(parameters, self.FIELD_PRECISION, context)
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code = self.parameterAsString(parameters, self.FORMULA, context)
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globalExpression = self.parameterAsString(parameters, self.GLOBAL, context)
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fields = source.fields()
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field = QgsField(field_name, field_type, '', width, precision)
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fields.append(field)
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new_ns = {}
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(sink, dest_id) = self.parameterAsSink(parameters, self.OUTPUT, context,
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fields, source.wkbType(), source.sourceCrs())
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# Run global code
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if globalExpression.strip() != '':
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try:
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bytecode = compile(globalExpression, '<string>', 'exec')
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exec(bytecode, new_ns)
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except:
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raise QgsProcessingException(
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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])))
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# Replace all fields tags
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fields = source.fields()
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num = 0
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for field in fields:
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field_name = str(field.name())
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replval = '__attr[' + str(num) + ']'
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code = code.replace('<' + field_name + '>', replval)
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num += 1
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# Replace all special vars
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code = code.replace('$id', '__id')
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code = code.replace('$geom', '__geom')
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need_id = code.find('__id') != -1
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need_geom = code.find('__geom') != -1
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need_attrs = code.find('__attr') != -1
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# Compile
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try:
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bytecode = compile(code, '<string>', 'exec')
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except:
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raise QgsProcessingException(
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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])))
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# Run
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features = source.getFeatures()
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total = 100.0 / source.featureCount() if source.featureCount() else 0
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for current, feat in enumerate(features):
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if feedback.isCanceled():
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break
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feedback.setProgress(int(current * total))
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attrs = feat.attributes()
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feat_id = feat.id()
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# Add needed vars
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if need_id:
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new_ns['__id'] = feat_id
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if need_geom:
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geom = feat.geometry()
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new_ns['__geom'] = geom
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if need_attrs:
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pyattrs = [a for a in attrs]
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new_ns['__attr'] = pyattrs
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# Clear old result
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if self.RESULT_VAR_NAME in new_ns:
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del new_ns[self.RESULT_VAR_NAME]
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# Exec
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exec(bytecode, new_ns)
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# Check result
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if self.RESULT_VAR_NAME not in new_ns:
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raise QgsProcessingException(
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self.tr("FieldPyculator code execute error\n"
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"Field code block does not return '{0}' variable! "
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"Please declare this variable in your code!").format(self.RESULT_VAR_NAME))
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# Write feature
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attrs.append(new_ns[self.RESULT_VAR_NAME])
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feat.setAttributes(attrs)
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sink.addFeature(feat, QgsFeatureSink.FastInsert)
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return {self.OUTPUT: dest_id}
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def checkParameterValues(self, parameters, context):
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# TODO check that formula is correct and fields exist
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return super(FieldsPyculator, self).checkParameterValues(parameters, context)
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