2017-12-30 17:16:16 +01:00

122 lines
4.7 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
v_net.py
--------
Date : December 2015
Copyright : (C) 2015 by Médéric Ribreux
Email : medspx at medspx dot fr
***************************************************************************
* *
* 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. *
* *
***************************************************************************
This Python module handles pre-treatment operations for v.net.* GRASS7 modules.
Before using a v.net module you often have to incorporate a points layer into
the network vector map.
"""
__author__ = 'Médéric Ribreux'
__date__ = 'December 2015'
__copyright__ = '(C) 2015, Médéric Ribreux'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import os
from qgis.core import QgsProcessingException
from processing.tools.system import getTempFilename
def incorporatePoints(alg, parameters, context, pointLayerName='points', networkLayerName='input'):
"""
incorporate points with lines to form a GRASS network
"""
# Grab the point layer and delete this parameter
pointLayer = alg.parameterAsVectorLayer(parameters, pointLayerName, context)
if pointLayer:
# Create an intermediate GRASS layer which is the combination of network + centers
intLayer = 'net' + os.path.basename(getTempFilename())
pointLayer = alg.exportedLayers[pointLayerName]
# Grab the network layer
lineLayer = alg.parameterAsVectorLayer(parameters, networkLayerName, context)
if lineLayer:
lineLayer = alg.exportedLayers[networkLayerName]
else:
raise QgsProcessingException(
alg.tr('GRASS GIS 7 v.net requires a lines layer!'))
threshold = alg.parameterAsDouble(parameters, 'threshold', context)
# Create the v.net connect command for point layer integration
command = u"v.net input={} points={} output={} operation=connect threshold={}".format(
lineLayer, pointLayer, intLayer, threshold)
alg.commands.append(command)
# Connect the point layer database to the layer 2 of the network
command = u"v.db.connect -o map={} table={} layer=2".format(intLayer, pointLayer)
alg.commands.append(command)
# remove undesired parameters
alg.removeParameter(pointLayerName)
# Use temp layer for input
alg.exportedLayers[networkLayerName] = intLayer
# Process the command
if 'threshold' in parameters:
alg.removeParameter('threshold')
alg.processCommand(parameters, context)
def variableOutput(alg, layers, parameters, context, nocats=True):
""" Handle variable data output for v.net modules:
:param layers:
layers is a dict of outputs:
{ 'outputName': ['srcLayer', 'output_type', output_layer_number, nocats],
...
}
where:
- outputName is the name of the output in the description file.
- srcLayer is the grass name of the layer to export.
- output_type is the GRASS datatype (point/line/area/etc.).
- output_layer_number is the GRASS layer number for multiple layers datasets.
- nocats indicates weither we need to also export without categories items.
:param parameters:
:param context:
:param nocats: do not add categories.
"""
for outputName, typeList in list(layers.items()):
if not isinstance(typeList, list):
continue
fileName = alg.parameterAsOutputLayer(parameters, outputName, context)
grassName = '{}{}'.format(typeList[0], alg.uniqueSuffix)
alg.exportVectorLayer(
grassName, fileName, typeList[1], typeList[2],
typeList[3])
def processOutputs(alg, parameters, context):
idx = alg.parameterAsInt(parameters, 'operation', context)
operations = alg.parameterDefinition('operation').options()
operation = operations[idx]
if operation == 'nodes':
outputParameter = {'output': ['output', 'point', 2, True]}
elif operation == 'connect':
outputParameter = {'output': ['output', 'line', 1, False]}
elif operation == 'arcs':
outputParameter = {'output': ['output', 'line', 1, True]}
variableOutput(alg, outputParameter, parameters, context)