QGIS/python/plugins/processing/algs/qgis/VectorSplit.py

# -*- coding: utf-8 -*-

"""
***************************************************************************
    VectorSplit.py
    ---------------------
    Date                 : September 2014
    Copyright            : (C) 2014 by Alexander Bruy
    Email                : alexander dot bruy 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__ = 'Alexander Bruy'
__date__ = 'September 2014'
__copyright__ = '(C) 2014, Alexander Bruy'

# This will get replaced with a git SHA1 when you do a git archive

__revision__ = '$Format:%H$'

import os

from processing.core.GeoAlgorithm import GeoAlgorithm
from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputDirectory
from processing.tools import dataobjects, vector
from processing.tools.system import mkdir

class VectorSplit(GeoAlgorithm):

    INPUT = 'INPUT'
    FIELD = 'FIELD'
    OUTPUT = 'OUTPUT'

    def defineCharacteristics(self):
        self.name = 'Split vector layer'
        self.group = 'Vector general tools'
        self.addParameter(ParameterVector(self.INPUT,
            self.tr('Input layer'), [ParameterVector.VECTOR_TYPE_ANY]))
        self.addParameter(ParameterTableField(self.FIELD,
            self.tr('Unique ID field'), self.INPUT))

        self.addOutput(OutputDirectory(self.OUTPUT, self.tr('Output directory')))

    def processAlgorithm(self, progress):
        layer = dataobjects.getObjectFromUri(
            self.getParameterValue(self.INPUT))
        fieldName = self.getParameterValue(self.FIELD)
        directory = self.getOutputValue(self.OUTPUT)

        mkdir(directory)

        fieldIndex = layer.fieldNameIndex(fieldName)
        uniqueValues = vector.uniqueValues(layer, fieldIndex)
        baseName = os.path.join(directory, '{0}_{1}'.format(layer.name(), fieldName))

        fields = layer.pendingFields()
        crs = layer.dataProvider().crs()
        geomType = layer.wkbType()

        total = 100.0 / len(uniqueValues)
        features = vector.features(layer)

        for count, i in enumerate(uniqueValues):
            fName = u'{0}_{1}.shp'.format(baseName, unicode(i).strip())

            writer = vector.VectorWriter(fName, None, fields, geomType, crs)
            for f in features:
                if f[fieldName] == i:
                    writer.addFeature(f)
            del writer

            progress.setPercentage(int(count * total))