mirror of
https://github.com/qgis/QGIS.git
synced 2025-02-28 00:17:30 -05:00
176 lines
6.9 KiB
Python
176 lines
6.9 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
FieldsCalculator.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'
|
|
__date__ = 'August 2012'
|
|
__copyright__ = '(C) 2012, Victor Olaya'
|
|
|
|
# This will get replaced with a git SHA1 when you do a git archive
|
|
|
|
__revision__ = '$Format:%H$'
|
|
|
|
from qgis.PyQt.QtCore import QVariant
|
|
from qgis.core import (QgsExpression,
|
|
QgsExpressionContext,
|
|
QgsExpressionContextUtils,
|
|
QgsFeature,
|
|
QgsField,
|
|
QgsDistanceArea,
|
|
QgsProject,
|
|
GEO_NONE,
|
|
QgsApplication)
|
|
from processing.core.GeoAlgorithm import GeoAlgorithm
|
|
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
|
|
from processing.core.parameters import ParameterVector
|
|
from processing.core.parameters import ParameterString
|
|
from processing.core.parameters import ParameterNumber
|
|
from processing.core.parameters import ParameterBoolean
|
|
from processing.core.parameters import ParameterSelection
|
|
from processing.core.outputs import OutputVector
|
|
from processing.tools import dataobjects, vector
|
|
|
|
from .ui.FieldsCalculatorDialog import FieldsCalculatorDialog
|
|
|
|
|
|
class FieldsCalculator(GeoAlgorithm):
|
|
|
|
INPUT_LAYER = 'INPUT_LAYER'
|
|
NEW_FIELD = 'NEW_FIELD'
|
|
FIELD_NAME = 'FIELD_NAME'
|
|
FIELD_TYPE = 'FIELD_TYPE'
|
|
FIELD_LENGTH = 'FIELD_LENGTH'
|
|
FIELD_PRECISION = 'FIELD_PRECISION'
|
|
FORMULA = 'FORMULA'
|
|
OUTPUT_LAYER = 'OUTPUT_LAYER'
|
|
|
|
TYPES = [QVariant.Double, QVariant.Int, QVariant.String, QVariant.Date]
|
|
|
|
def icon(self):
|
|
return QgsApplication.getThemeIcon("/providerQgis.svg")
|
|
|
|
def svgIconPath(self):
|
|
return QgsApplication.iconPath("providerQgis.svg")
|
|
|
|
def group(self):
|
|
return self.tr('Vector table tools')
|
|
|
|
def name(self):
|
|
return 'fieldcalculator'
|
|
|
|
def displayName(self):
|
|
return self.tr('Field calculator')
|
|
|
|
def defineCharacteristics(self):
|
|
self.type_names = [self.tr('Float'),
|
|
self.tr('Integer'),
|
|
self.tr('String'),
|
|
self.tr('Date')]
|
|
|
|
self.addParameter(ParameterVector(self.INPUT_LAYER,
|
|
self.tr('Input layer')))
|
|
self.addParameter(ParameterString(self.FIELD_NAME,
|
|
self.tr('Result field name')))
|
|
self.addParameter(ParameterSelection(self.FIELD_TYPE,
|
|
self.tr('Field type'), self.type_names))
|
|
self.addParameter(ParameterNumber(self.FIELD_LENGTH,
|
|
self.tr('Field length'), 1, 255, 10))
|
|
self.addParameter(ParameterNumber(self.FIELD_PRECISION,
|
|
self.tr('Field precision'), 0, 15, 3))
|
|
self.addParameter(ParameterBoolean(self.NEW_FIELD,
|
|
self.tr('Create new field'), True))
|
|
self.addParameter(ParameterString(self.FORMULA, self.tr('Formula')))
|
|
self.addOutput(OutputVector(self.OUTPUT_LAYER, self.tr('Calculated')))
|
|
|
|
def processAlgorithm(self, context, feedback):
|
|
layer = dataobjects.getLayerFromString(self.getParameterValue(self.INPUT_LAYER))
|
|
fieldName = self.getParameterValue(self.FIELD_NAME)
|
|
fieldType = self.TYPES[self.getParameterValue(self.FIELD_TYPE)]
|
|
width = self.getParameterValue(self.FIELD_LENGTH)
|
|
precision = self.getParameterValue(self.FIELD_PRECISION)
|
|
newField = self.getParameterValue(self.NEW_FIELD)
|
|
formula = self.getParameterValue(self.FORMULA)
|
|
|
|
output = self.getOutputFromName(self.OUTPUT_LAYER)
|
|
|
|
fields = layer.fields()
|
|
if newField:
|
|
fields.append(QgsField(fieldName, fieldType, '', width, precision))
|
|
|
|
writer = output.getVectorWriter(fields, layer.wkbType(),
|
|
layer.crs())
|
|
|
|
exp = QgsExpression(formula)
|
|
|
|
da = QgsDistanceArea()
|
|
da.setSourceCrs(layer.crs())
|
|
da.setEllipsoid(QgsProject.instance().ellipsoid())
|
|
exp.setGeomCalculator(da)
|
|
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
|
|
exp.setAreaUnits(QgsProject.instance().areaUnits())
|
|
|
|
exp_context = QgsExpressionContext(QgsExpressionContextUtils.globalProjectLayerScopes(layer))
|
|
|
|
if not exp.prepare(exp_context):
|
|
raise GeoAlgorithmExecutionException(
|
|
self.tr('Evaluation error: {0}').format(exp.evalErrorString()))
|
|
|
|
outFeature = QgsFeature()
|
|
outFeature.initAttributes(len(fields))
|
|
outFeature.setFields(fields)
|
|
|
|
error = ''
|
|
calculationSuccess = True
|
|
|
|
features = vector.features(layer)
|
|
total = 100.0 / len(features)
|
|
|
|
rownum = 1
|
|
for current, f in enumerate(features):
|
|
rownum = current + 1
|
|
exp_context.setFeature(f)
|
|
exp_context.lastScope().setVariable("row_number", rownum)
|
|
value = exp.evaluate(exp_context)
|
|
if exp.hasEvalError():
|
|
calculationSuccess = False
|
|
error = exp.evalErrorString()
|
|
break
|
|
else:
|
|
outFeature.setGeometry(f.geometry())
|
|
for fld in f.fields():
|
|
outFeature[fld.name()] = f[fld.name()]
|
|
outFeature[fieldName] = value
|
|
writer.addFeature(outFeature)
|
|
|
|
feedback.setProgress(int(current * total))
|
|
del writer
|
|
|
|
if not calculationSuccess:
|
|
raise GeoAlgorithmExecutionException(
|
|
self.tr('An error occurred while evaluating the calculation '
|
|
'string:\n{0}').format(error))
|
|
|
|
def checkParameterValuesBeforeExecuting(self):
|
|
newField = self.getParameterValue(self.NEW_FIELD)
|
|
fieldName = self.getParameterValue(self.FIELD_NAME).strip()
|
|
if newField and len(fieldName) == 0:
|
|
return self.tr('Field name is not set. Please enter a field name')
|
|
|
|
def getCustomParametersDialog(self):
|
|
return FieldsCalculatorDialog(self)
|