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[processing] Fixes for field calculator and field mapper
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- respect project distance, area and ellipsoid settings
- ensure expression variables are correctly evaluated

(cherry-picked from d32c41a)
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@nyalldawson
nyalldawson committed Mar 1, 2016
1 parent 2b72350 commit 3ea7860
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Showing 3 changed files with 44 additions and 8 deletions.
16 changes: 12 additions & 4 deletions python/plugins/processing/algs/qgis/FieldsCalculator.py
View file
Expand Up @@ -26,7 +26,7 @@
__revision__ = '$Format:%H$'

from PyQt4.QtCore import QVariant
from qgis.core import QgsExpression, QgsFeature, QgsField, QgsDistanceArea, QgsProject, GEO_NONE
from qgis.core import QgsExpression, QgsExpressionContext, QgsExpressionContextUtils, QgsFeature, QgsField, QgsDistanceArea, QgsProject, GEO_NONE
from qgis.utils import iface
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
Expand Down Expand Up @@ -111,8 +111,15 @@ def processAlgorithm(self, progress):
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])
exp.setGeomCalculator(da)
exp.setDistanceUnits(QgsProject.instance().distanceUnits())
exp.setAreaUnits(QgsProject.instance().areaUnits())

if not exp.prepare(layer.pendingFields()):
exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))

if not exp.prepare(exp_context):
raise GeoAlgorithmExecutionException(
self.tr('Evaluation error: %s' % exp.evalErrorString()))

Expand All @@ -129,8 +136,9 @@ def processAlgorithm(self, progress):
rownum = 1
for current, f in enumerate(features):
rownum = current + 1
exp.setCurrentRowNumber(rownum)
value = exp.evaluate(f)
exp_context.setFeature(f)
exp_context.lastScope().setVariable("row_number", rownum)
value = exp.evaluate(exp_context)
if exp.hasEvalError():
calculationSuccess = False
error = exp.evalErrorString()
Expand Down
27 changes: 23 additions & 4 deletions python/plugins/processing/algs/qgis/FieldsMapper.py
View file
Expand Up @@ -26,7 +26,8 @@
__revision__ = '$Format:%H$'


from qgis.core import QgsField, QgsExpression, QgsFeature
from qgis.core import QgsField, QgsExpression, QgsExpressionContext, QgsExpressionContextUtils, QgsDistanceArea, QgsProject, QgsFeature, GEO_NONE
from qgis.utils import iface
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
Expand Down Expand Up @@ -68,19 +69,36 @@ def processAlgorithm(self, progress):
provider = layer.dataProvider()
fields = []
expressions = []

da = QgsDistanceArea()
da.setSourceCrs(layer.crs().srsid())
da.setEllipsoidalMode(
iface.mapCanvas().mapSettings().hasCrsTransformEnabled())
da.setEllipsoid(QgsProject.instance().readEntry(
'Measure', '/Ellipsoid', GEO_NONE)[0])

exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(layer))

for field_def in mapping:
fields.append(QgsField(name=field_def['name'],
type=field_def['type'],
len=field_def['length'],
prec=field_def['precision']))

expression = QgsExpression(field_def['expression'])
expression.setGeomCalculator(da)
expression.setDistanceUnits(QgsProject.instance().distanceUnits())
expression.setAreaUnits(QgsProject.instance().areaUnits())

if expression.hasParserError():
raise GeoAlgorithmExecutionException(
self.tr(u'Parser error in expression "{}": {}')
.format(unicode(field_def['expression']),
unicode(expression.parserErrorString())))
expression.prepare(provider.fields())
expression.prepare(exp_context)
if expression.hasEvalError():
raise GeoAlgorithmExecutionException(
self.tr(u'Evaluation error in expression "{}": {}')
Expand Down Expand Up @@ -108,8 +126,9 @@ def processAlgorithm(self, progress):
for i in xrange(0, len(mapping)):
field_def = mapping[i]
expression = expressions[i]
expression.setCurrentRowNumber(rownum)
value = expression.evaluate(inFeat)
exp_context.setFeature(inFeat)
exp_context.lastScope().setVariable("row_number", rownum)
value = expression.evaluate(exp_context)
if expression.hasEvalError():
calculationSuccess = False
error = expression.evalErrorString()
Expand Down
9 changes: 9 additions & 0 deletions python/plugins/processing/algs/qgis/ui/FieldsCalculatorDialog.py
View file
Expand Up @@ -31,6 +31,7 @@
from PyQt4 import uic
from PyQt4.QtCore import Qt, QSettings
from PyQt4.QtGui import QDialog, QFileDialog, QApplication, QCursor, QMessageBox
from qgis.core import QgsExpressionContext, QgsExpressionContextUtils
from qgis.gui import QgsEncodingFileDialog

from processing.core.ProcessingConfig import ProcessingConfig
Expand Down Expand Up @@ -95,6 +96,14 @@ def updateLayer(self):
self.builder.setLayer(self.layer)
self.builder.loadFieldNames()

exp_context = QgsExpressionContext()
exp_context.appendScope(QgsExpressionContextUtils.globalScope())
exp_context.appendScope(QgsExpressionContextUtils.projectScope())
exp_context.appendScope(QgsExpressionContextUtils.layerScope(self.layer))
exp_context.lastScope().setVariable("row_number", 1)
exp_context.setHighlightedVariables(["row_number"])
self.builder.setExpressionContext(exp_context)

self.populateFields()

def setupSpinboxes(self, index):
Expand Down

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