Python Algorithm.addResultToLayer方法代碼示例

# 需要導入模塊: from algorithm import Algorithm [as 別名]
# 或者: from algorithm.Algorithm import addResultToLayer [as 別名]
    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()

# 需要導入模塊: from algorithm import Algorithm [as 別名]
# 或者: from algorithm.Algorithm import addResultToLayer [as 別名]

#.........這裏部分代碼省略.........
        if msgType == QgsMessageLog.CRITICAL:
            msgType = QgsMessageBar.CRITICAL
        
        if msgType == QgsMessageLog.WARNING:
            duration = 3
            msgType = QgsMessageBar.WARNING

        iface.messageBar().pushMessage(message, msgType, duration)
            
    def manageError(self, ex, exceptionMessage):
        ''' Do actions in case of alg thread error. Now only notify exception 
        '''
        QgsMessageLog.logMessage(exceptionMessage, 'QTraffic', QgsMessageLog.CRITICAL)
        iface.messageBar().pushMessage(exceptionMessage, QgsMessageBar.CRITICAL)
        
    def manageFinished(self, success, reason):
        ''' Do action after notify that alg is finished. These are the postprocessing steps
        1) merge result to the output layer
        2) add the layer to canvas in case it is new
        3) notify edn of processing
        4) terminate the thread
        '''
        # finish the thread
        self.thread.quit()
        
        # check result
        if not success:
            QgsMessageLog.logMessage('Failed execution: {}'.format(reason), 'QTraffic', QgsMessageLog.CRITICAL)
            iface.messageBar().pushCritical('QTraffic', self.tr("Error executing the algorithm: {}".format(reason)))
            return
        
        # prepare result
        try:
            self.alg.addResultToLayer(self.outLayer)
        except Exception as ex:
            traceback.print_exc()
            QgsMessageLog.logMessage('Cannot add result to layer: {}'.format(str(ex)), 'QTraffic', QgsMessageLog.CRITICAL)
            iface.messageBar().pushCritical('QTraffic', self.tr("Cannot add result to layer"))
            return
        
        # add or refresh rsult vector layer
        addToInputLayer = self.gui.addToOriginaLayer_RButton.isChecked()
        if not addToInputLayer:
            QgsMapLayerRegistry.instance().addMapLayer(self.outLayer)
        iface.mapCanvas().refresh()
        
        # notify the user the end of process
        iface.messageBar().pushSuccess('QTraffic', self.tr('Alg terminated successfully'))
        
    def validate(self):
        ''' pre calcluation validation related only to this tab
        Mandatory:
            At least an output parameters have to be set
            if "create new layer" a new layer name have to be set
        '''
        addToInputLayer = self.gui.addToOriginaLayer_RButton.isChecked()
        newOutputLayer = self.gui.outFile_LEdit.text()
        if (not addToInputLayer and
            not newOutputLayer):
            message = self.tr('No output vector specified')
            iface.messageBar().pushMessage(message, QgsMessageBar.CRITICAL)
            return False
        
        Gasoline_Consumption = self.gui.fuelEnergyConsumptionGasoline_CBox.isChecked()
        Diesel_Consumption = self.gui.fuelEnergyConsumptionDiesel_CBox.isChecked()
        LPG_Consumption = self.gui.fuelEnergyConsumptionLPG_CBox.isChecked()