QGIS/python/plugins/processing/algs/qgis/SaveSelectedFeatures.py
Nyall Dawson f84d703234 Add method QgsProcessingUtils::mapLayerFromString
Algorithms and other processing code should use this method
(instead of dataobjects.getLayerFromString) to
retrieve layers from a string, as it considers the processing
context and allows resolving strings to temporarily stored layers.

This permits processing models to function correctly when
intermediate results are stored as memory layers. Subsequent
model algorithms can then access these temporary layers as inputs.
All temporary layers will be removed when the context object
is destroyed after the model algorithm is run.
2017-05-02 12:33:04 +10:00

81 lines
3.0 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
SaveSelectedFeatures.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.core import QgsApplication
from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
from processing.core.parameters import ParameterVector
from processing.core.outputs import OutputVector
from processing.tools import dataobjects
class SaveSelectedFeatures(GeoAlgorithm):
OUTPUT_LAYER = 'OUTPUT_LAYER'
INPUT_LAYER = 'INPUT_LAYER'
def icon(self):
return QgsApplication.getThemeIcon("/providerQgis.svg")
def svgIconPath(self):
return QgsApplication.iconPath("providerQgis.svg")
def group(self):
return self.tr('Vector general tools')
def name(self):
return 'saveselectedfeatures'
def displayName(self):
return self.tr('Save selected features')
def defineCharacteristics(self):
self.addParameter(ParameterVector(self.INPUT_LAYER,
self.tr('Input layer')))
self.addOutput(OutputVector(self.OUTPUT_LAYER,
self.tr('Selection')))
def processAlgorithm(self, context, feedback):
inputFilename = self.getParameterValue(self.INPUT_LAYER)
output = self.getOutputFromName(self.OUTPUT_LAYER)
vectorLayer = dataobjects.QgsProcessingUtils.mapLayerFromString(inputFilename, context)
writer = output.getVectorWriter(vectorLayer.fields(), vectorLayer.wkbType(), vectorLayer.crs(), context)
features = vectorLayer.getSelectedFeatures()
count = int(vectorLayer.selectedFeatureCount())
if count == 0:
raise GeoAlgorithmExecutionException(self.tr('There are no selected features in the input layer.'))
total = 100.0 / count
for current, feat in enumerate(features):
writer.addFeature(feat)
feedback.setProgress(int(current * total))
del writer