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[processing] Use faster expression request for ExtractByAttribute

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This commit is contained in:
Nyall Dawson 2015-11-16 16:10:30 +11:00
parent e15962eea9
commit 48afc425dc
1 changed files with 7 additions and 10 deletions
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17
python/plugins/processing/algs/qgis/ExtractByAttribute.py
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@ -26,7 +26,7 @@ __copyright__ = '(C) 2010, Michael Minn'
__revision__ = '$Format:%H$'
from PyQt4.QtCore import QVariant
from qgis.core import QgsExpression
from qgis.core import QgsExpression, QgsFeatureRequest
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
@ -117,15 +117,12 @@ class ExtractByAttribute(GeoAlgorithm):
self.tr('Unsupported field type "%s"' % fields[idx].typeName()))
expression = QgsExpression(expr)
expression.prepare(fields)
if not expression.hasParserError():
req = QgsFeatureRequest(expression)
else:
raise GeoAlgorithmExecutionException(expression.parserErrorString())
features = vector.features(layer)
count = len(features)
total = 100.0 / float(count)
for count, f in enumerate(features):
if expression.evaluate(f, fields):
writer.addFeature(f)
progress.setPercentage(int(count * total))
for f in layer.getFeatures(req):
writer.addFeature(f)
del writer