Nyall Dawson fd2c18ee16 Refactor processing writer to use QgsFeatureSink, and to store
temporary output layers in the provided processing context

Should fix loss of intermediate memory layers when running
a multi-step model
2017-04-26 17:38:40 +10:00

32 lines
1006 B
Python

##Centroids=name
##Geometry=group
##INPUT_LAYER=vector
##OUTPUT_LAYER=output vector
from qgis.core import QgsWkbTypes, QgsGeometry, QgsProcessingUtils
from processing.tools.vector import createVectorWriter
from processing.tools import dataobjects
layer = dataobjects.getLayerFromString(INPUT_LAYER)
fields = layer.fields()
writer, writer_dest, writer_layer = createVectorWriter(OUTPUT_LAYER, 'utf-8', fields, QgsWkbTypes.Point, layer.crs(),
context)
features = QgsProcessingUtils.getFeatures(layer, context)
count = QgsProcessingUtils.featureCount(layer, context)
if count == 0:
raise GeoAlgorithmExecutionException('Input layer contains no features.')
total = 100.0 / count
for count, f in enumerate(features):
outputFeature = f
if f.hasGeometry():
outputGeometry = f.geometry().centroid()
outputFeature.setGeometry(outputGeometry)
writer.addFeature(outputFeature)
feedback.setProgress(int(count * total))