mirror of
https://github.com/qgis/QGIS.git
synced 2025-04-28 00:05:04 -04:00
f84d703234
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.
75 lines
2.6 KiB
Python
75 lines
2.6 KiB
Python
# -*- coding: utf-8 -*-
|
|
|
|
"""
|
|
***************************************************************************
|
|
TruncateTable.py
|
|
-----------------------
|
|
Date : January 2017
|
|
Copyright : (C) 2017 by Nyall Dawson
|
|
Email : nyall dot dawson 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__ = 'Nyall Dawson'
|
|
__date__ = 'January 2017'
|
|
__copyright__ = '(C) 2017, Nyall Dawson'
|
|
|
|
# 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.parameters import ParameterTable
|
|
from processing.core.outputs import OutputVector
|
|
from processing.core.GeoAlgorithmExecutionException import GeoAlgorithmExecutionException
|
|
from processing.tools import dataobjects
|
|
|
|
|
|
class TruncateTable(GeoAlgorithm):
|
|
|
|
INPUT = 'INPUT'
|
|
OUTPUT = 'OUTPUT'
|
|
|
|
def icon(self):
|
|
return QgsApplication.getThemeIcon("/providerQgis.svg")
|
|
|
|
def svgIconPath(self):
|
|
return QgsApplication.iconPath("providerQgis.svg")
|
|
|
|
def tags(self):
|
|
return self.tr('empty,delete,layer,clear,features').split(',')
|
|
|
|
def group(self):
|
|
return self.tr('Vector general tools')
|
|
|
|
def name(self):
|
|
return 'truncatetable'
|
|
|
|
def displayName(self):
|
|
return self.tr('Truncate table')
|
|
|
|
def defineCharacteristics(self):
|
|
self.addParameter(ParameterTable(self.INPUT,
|
|
self.tr('Input Layer')))
|
|
self.addOutput(OutputVector(self.OUTPUT,
|
|
self.tr('Truncated layer'), True))
|
|
|
|
def processAlgorithm(self, context, feedback):
|
|
file_name = self.getParameterValue(self.INPUT)
|
|
layer = dataobjects.QgsProcessingUtils.mapLayerFromString(file_name, context)
|
|
provider = layer.dataProvider()
|
|
|
|
if not provider.truncate():
|
|
raise GeoAlgorithmExecutionException(
|
|
self.tr('Could not truncate table.'))
|
|
|
|
self.setOutputValue(self.OUTPUT, file_name)
|