def calculate(self):
''' Prepare environment to run the alg and run it. After run, merge produced
data basing on plugin configuration
'''
alg = Algorithm()
roadLayer = self.gui.getRoadLayer()
# prepare layer where to add result
addToInputLayer = self.gui.addToOriginaLayer_RButton.isChecked()
newOutputLayer = self.gui.outFile_LEdit.text()
self.outLayer = roadLayer
if not addToInputLayer:
if not newOutputLayer:
message = self.tr('No output vector specified')
QgsMessageLog.logMessage(message, 'QTraffic', QgsMessageLog.CRITICAL)
iface.messageBar().pushCritical('QTraffic', message)
return
# copy input layer to the new one
writeError = QgsVectorFileWriter.writeAsVectorFormat(roadLayer, newOutputLayer, 'utf-8', roadLayer.crs())
if writeError != QgsVectorFileWriter.NoError:
message = self.tr('Error writing vector file {}'.format(newOutputLayer))
QgsMessageLog.logMessage(message, 'QTraffic', QgsMessageLog.CRITICAL)
iface.messageBar().pushCritical('QTraffic', message)
return
# load the layer
newLayerName =os.path.splitext(os.path.basename( newOutputLayer ))[0]
self.outLayer = QgsVectorLayer(newOutputLayer, newLayerName, 'ogr')
if not self.outLayer.isValid():
message = self.tr('Error loading vector file {}'.format(newOutputLayer))
QgsMessageLog.logMessage(message, 'QTraffic', QgsMessageLog.CRITICAL)
iface.messageBar().pushCritical('QTraffic', message)
return
# prepare environment
try:
alg.setProject(self.project)
alg.setLayer( roadLayer )
alg.init()
alg.prepareRun()
except:
traceback.print_exc()
message = self.tr('Error preparing context for the algoritm')
QgsMessageLog.logMessage(message, 'QTraffic', QgsMessageLog.CRITICAL)
iface.messageBar().pushCritical('QTraffic', message)
return
# run the alg
success = alg.run()
if not success:
return
# prepare result
try:
alg.addResultToLayer(self.outLayer)
except:
return
# add or refresh rsult vector layer
if not addToInputLayer:
QgsMapLayerRegistry.instance().addMapLayer(self.outLayer)
iface.mapCanvas().refresh()
