""" *************************************************************************** OneSideBuffer.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" from qgis.core import ( QgsProcessing, QgsProcessingException, QgsProcessingParameterDefinition, QgsProcessingParameterDistance, QgsProcessingParameterFeatureSource, QgsProcessingParameterEnum, QgsProcessingParameterField, QgsProcessingParameterString, QgsProcessingParameterBoolean, QgsProcessingParameterVectorDestination, ) from processing.algs.gdal.GdalAlgorithm import GdalAlgorithm from processing.algs.gdal.GdalUtils import GdalUtils class OneSideBuffer(GdalAlgorithm): INPUT = "INPUT" FIELD = "FIELD" BUFFER_SIDE = "BUFFER_SIDE" GEOMETRY = "GEOMETRY" DISTANCE = "DISTANCE" DISSOLVE = "DISSOLVE" EXPLODE_COLLECTIONS = "EXPLODE_COLLECTIONS" OPTIONS = "OPTIONS" OUTPUT = "OUTPUT" def __init__(self): super().__init__() def initAlgorithm(self, config=None): self.bufferSides = [self.tr("Right"), self.tr("Left")] self.addParameter( QgsProcessingParameterFeatureSource( self.INPUT, self.tr("Input layer"), [QgsProcessing.SourceType.TypeVectorLine], ) ) self.addParameter( QgsProcessingParameterString( self.GEOMETRY, self.tr("Geometry column name"), defaultValue="geometry" ) ) self.addParameter( QgsProcessingParameterDistance( self.DISTANCE, self.tr("Buffer distance"), defaultValue=10, parentParameterName=self.INPUT, ) ) self.addParameter( QgsProcessingParameterEnum( self.BUFFER_SIDE, self.tr("Buffer side"), options=self.bufferSides, allowMultiple=False, defaultValue=0, ) ) self.addParameter( QgsProcessingParameterField( self.FIELD, self.tr("Dissolve by attribute"), None, self.INPUT, QgsProcessingParameterField.DataType.Any, optional=True, ) ) self.addParameter( QgsProcessingParameterBoolean( self.DISSOLVE, self.tr("Dissolve all results"), defaultValue=False ) ) self.addParameter( QgsProcessingParameterBoolean( self.EXPLODE_COLLECTIONS, self.tr( "Produce one feature for each geometry in any kind of geometry collection in the source file" ), defaultValue=False, ) ) options_param = QgsProcessingParameterString( self.OPTIONS, self.tr("Additional creation options"), defaultValue="", optional=True, ) options_param.setFlags( options_param.flags() | QgsProcessingParameterDefinition.Flag.FlagAdvanced ) self.addParameter(options_param) self.addParameter( QgsProcessingParameterVectorDestination( self.OUTPUT, self.tr("One-sided buffer"), QgsProcessing.SourceType.TypeVectorPolygon, ) ) def name(self): return "onesidebuffer" def displayName(self): return self.tr("One side buffer") def group(self): return self.tr("Vector geoprocessing") def groupId(self): return "vectorgeoprocessing" def commandName(self): return "ogr2ogr" def getConsoleCommands(self, parameters, context, feedback, executing=True): source = self.parameterAsSource(parameters, self.INPUT, context) if source is None: raise QgsProcessingException( self.invalidSourceError(parameters, self.INPUT) ) fields = source.fields() input_details = self.getOgrCompatibleSource( self.INPUT, parameters, context, feedback, executing ) if not input_details.layer_name: raise QgsProcessingException( self.invalidSourceError(parameters, self.INPUT) ) geometry = self.parameterAsString(parameters, self.GEOMETRY, context) if input_details.geometry_column_name: geometry = input_details.geometry_column_name distance = self.parameterAsDouble(parameters, self.DISTANCE, context) side = self.parameterAsEnum(parameters, self.BUFFER_SIDE, context) fieldName = self.parameterAsString(parameters, self.FIELD, context) dissolve = self.parameterAsBoolean(parameters, self.DISSOLVE, context) options = self.parameterAsString(parameters, self.OPTIONS, context) outFile = self.parameterAsOutputLayer(parameters, self.OUTPUT, context) self.setOutputValue(self.OUTPUT, outFile) output_details = GdalUtils.gdal_connection_details_from_uri(outFile, context) other_fields_exist = any(True for f in fields if f.name() != geometry) other_fields = ",*" if other_fields_exist else "" arguments = [ output_details.connection_string, input_details.connection_string, "-dialect", "sqlite", "-sql", ] if dissolve or fieldName: sql = f'SELECT ST_Union(ST_SingleSidedBuffer({geometry}, {distance}, {side})) AS {geometry}{other_fields} FROM "{input_details.layer_name}"' else: sql = f'SELECT ST_SingleSidedBuffer({geometry}, {distance}, {side}) AS {geometry}{other_fields} FROM "{input_details.layer_name}"' if fieldName: sql = f'{sql} GROUP BY "{fieldName}"' arguments.append(sql) if self.parameterAsBoolean(parameters, self.EXPLODE_COLLECTIONS, context): arguments.append("-explodecollections") if input_details.open_options: arguments.extend(input_details.open_options_as_arguments()) if input_details.credential_options: arguments.extend(input_details.credential_options_as_arguments()) if options: arguments.append(options) if output_details.format: arguments.append(f"-f {output_details.format}") return ["ogr2ogr", GdalUtils.escapeAndJoin(arguments)]