ogr2ogrbuffer.py

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

"""
***************************************************************************
    ogr2ogrbuffer.py
    ---------------------
    Date                 : Janaury 2015
    Copyright            : (C) 2015 by Giovanni Manghi
    Email                : giovanni dot manghi at naturalgis dot pt
***************************************************************************
*                                                                         *
*   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__ = 'Giovanni Manghi'
__date__ = 'January 2015'
__copyright__ = '(C) 2015, Giovanni Manghi'

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

__revision__ = '$Format:%H$'

from processing.core.parameters import ParameterVector
from processing.core.parameters import ParameterString
from processing.core.parameters import ParameterNumber
from processing.core.parameters import ParameterBoolean
from processing.core.parameters import ParameterTableField
from processing.core.outputs import OutputVector

from processing.tools.system import isWindows

from processing.algs.gdal.OgrAlgorithm import OgrAlgorithm
from processing.algs.gdal.GdalUtils import GdalUtils

class Ogr2OgrBuffer(OgrAlgorithm):

    OUTPUT_LAYER = 'OUTPUT_LAYER'
    INPUT_LAYER = 'INPUT_LAYER'
    GEOMETRY = 'GEOMETRY'
    DISTANCE = 'DISTANCE'   
    DISSOLVEALL = 'DISSOLVEALL'
    FIELD = 'FIELD'
    MULTI = 'MULTI' 
    OPTIONS = 'OPTIONS'

    def defineCharacteristics(self):
        self.name = 'Buffer vectors'
        self.group = '[OGR] Geoprocessing'

        self.addParameter(ParameterVector(self.INPUT_LAYER, 'Input layer',
                          [ParameterVector.VECTOR_TYPE_ANY], False))
        self.addParameter(ParameterString(self.GEOMETRY, 'Geometry column name ("geometry" for Shapefiles, may be different for other formats)',
                          'geometry', optional=False))
        self.addParameter(ParameterString(self.DISTANCE,'Buffer distance', '1000', optional=False))
        self.addParameter(ParameterBoolean(self.DISSOLVEALL,
                          'Dissolve all results?', False))
        self.addParameter(ParameterTableField(self.FIELD, 'Dissolve by attribute',
                          self.INPUT_LAYER, optional=True))
        self.addParameter(ParameterBoolean(self.MULTI,
                          'Output as singlepart geometries (only used when dissolving by attribute)?', False))
        self.addParameter(ParameterString(self.OPTIONS, 'Additional creation options (see ogr2ogr manual)',
                          '', optional=True))
        self.addOutput(OutputVector(self.OUTPUT_LAYER, 'Output layer'))

    def processAlgorithm(self, progress):
        inLayer = self.getParameterValue(self.INPUT_LAYER)
        ogrLayer = self.ogrConnectionString(inLayer)[1:-1]
        layername = "'" + self.ogrLayerName(inLayer) + "'"
        geometry = unicode(self.getParameterValue(self.GEOMETRY))
        distance = unicode(self.getParameterValue(self.DISTANCE))
        dissolveall = self.getParameterValue(self.DISSOLVEALL)
        field = unicode(self.getParameterValue(self.FIELD)) 
        multi = self.getParameterValue(self.MULTI)
        
        output = self.getOutputFromName(self.OUTPUT_LAYER)
        outFile = output.value

        output = self.ogrConnectionString(outFile)
        options = unicode(self.getParameterValue(self.OPTIONS))

        arguments = []
        arguments.append(output)
        arguments.append(ogrLayer)
        arguments.append(self.ogrLayerName(inLayer))
        if dissolveall or field != 'None':
           arguments.append('-dialect sqlite -sql "SELECT ST_Union(ST_Buffer(')
        else:
           arguments.append('-dialect sqlite -sql "SELECT ST_Buffer(')           
        arguments.append(geometry)
        arguments.append(',')
        arguments.append(distance)
        if dissolveall or field != 'None':
           arguments.append(')),*')  
        else:
           arguments.append('),*')  
        arguments.append('FROM')
        arguments.append(layername)
        if field != 'None':
           arguments.append('GROUP')
           arguments.append('BY')         
           arguments.append(field) 
        arguments.append('"')   
        if field != 'None' and multi:
           arguments.append('-explodecollections')

        if len(options) > 0:
            arguments.append(options)
            
        commands = []
        if isWindows():
            commands = ['cmd.exe', '/C ', 'ogr2ogr.exe',
                        GdalUtils.escapeAndJoin(arguments)]
        else:
            commands = ['ogr2ogr', GdalUtils.escapeAndJoin(arguments)]

        GdalUtils.runGdal(commands, progress)