QGIS/python/plugins/processing/algs/grass7/Grass7Algorithm.py
2017-11-04 15:31:21 +01:00

734 lines
33 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
Grass7Algorithm.py
---------------------
Date : February 2015
Copyright : (C) 2014-2015 by Victor Olaya
Email : volayaf 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. *
* *
***************************************************************************
"""
from builtins import str
from builtins import range
__author__ = 'Victor Olaya'
__date__ = 'February 2015'
__copyright__ = '(C) 2012-2015, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import sys
import os
import uuid
import importlib
from qgis.PyQt.QtCore import QCoreApplication, QUrl
from qgis.core import (QgsRasterLayer,
QgsApplication,
QgsMapLayer,
QgsProcessingUtils,
QgsMessageLog,
QgsVectorFileWriter,
QgsProcessingAlgorithm,
QgsProcessingParameterDefinition,
QgsProcessingException,
QgsProcessingParameterExtent,
QgsProcessingParameterEnum,
QgsProcessingParameterNumber,
QgsProcessingParameterString,
QgsProcessingParameterPoint,
QgsProcessingParameterBoolean,
QgsProcessingParameterVectorLayer,
QgsProcessingParameterRasterLayer,
QgsProcessingParameterMultipleLayers,
QgsProcessingParameterVectorDestination,
QgsProcessingParameterRasterDestination,
QgsProcessingParameterFileDestination,
QgsProcessingOutputVectorLayer,
QgsProcessingOutputRasterLayer,
QgsProcessingOutputHtml)
from qgis.utils import iface
from processing.core.ProcessingConfig import ProcessingConfig
from processing.core.parameters import (getParameterFromString)
from .Grass7Utils import Grass7Utils
from processing.tools import dataobjects, system
pluginPath = os.path.normpath(os.path.join(
os.path.split(os.path.dirname(__file__))[0], os.pardir))
class Grass7Algorithm(QgsProcessingAlgorithm):
GRASS_OUTPUT_TYPE_PARAMETER = 'GRASS_OUTPUT_TYPE_PARAMETER'
GRASS_MIN_AREA_PARAMETER = 'GRASS_MIN_AREA_PARAMETER'
GRASS_SNAP_TOLERANCE_PARAMETER = 'GRASS_SNAP_TOLERANCE_PARAMETER'
GRASS_REGION_EXTENT_PARAMETER = 'GRASS_REGION_PARAMETER'
GRASS_REGION_CELLSIZE_PARAMETER = 'GRASS_REGION_CELLSIZE_PARAMETER'
GRASS_REGION_ALIGN_TO_RESOLUTION = '-a_r.region'
OUTPUT_TYPES = ['auto', 'point', 'line', 'area']
def __init__(self, descriptionfile):
super().__init__()
self._name = ''
self._display_name = ''
self._group = ''
self.grass7Name = ''
self.params = []
self.hardcodedStrings = []
self.descriptionFile = descriptionfile
# Default GRASS parameters
self.region = None
self.cellSize = None
self.snaptTolerance = None
self.outputType = None
self.minArea = None
self.alignToResolution = None
# Load parameters from a description file
self.defineCharacteristicsFromFile()
self.numExportedLayers = 0
# Do we need this anymore?
self.uniqueSuffix = str(uuid.uuid4()).replace('-', '')
# Use the ext mechanism
name = self.name().replace('.', '_')
try:
self.module = importlib.import_module('processing.algs.grass7.ext.' + name)
except ImportError:
self.module = None
def createInstance(self):
return self.__class__(self.descriptionFile)
def name(self):
return self._name
def displayName(self):
return self._display_name
def group(self):
return self._group
def icon(self):
return QgsApplication.getThemeIcon("/providerGrass.svg")
def svgIconPath(self):
return QgsApplication.iconPath("providerGrass.svg")
def tr(self, string, context=''):
if context == '':
context = self.__class__.__name__
return QCoreApplication.translate(context, string)
def helpUrl(self):
helpPath = Grass7Utils.grassHelpPath()
if helpPath == '':
return None
if os.path.exists(helpPath):
return QUrl.fromLocalFile(os.path.join(helpPath, '{}.html'.format(self.grass7Name))).toString()
else:
return helpPath + '{}.html'.format(self.grass7Name)
def getParameterDescriptions(self):
descs = {}
_, helpfile = self.help()
try:
with open(helpfile) as infile:
lines = infile.readlines()
for i in range(len(lines)):
if lines[i].startswith('<DT><b>'):
for param in self.parameterDefinitions():
searchLine = '<b>' + param.name() + '</b>'
if searchLine in lines[i]:
i += 1
descs[param.name()] = (lines[i])[4:-6]
break
except Exception:
pass
return descs
def initAlgorithm(self, config=None):
"""
Algorithm initialization
"""
for p in self.params:
# We use createOutput argument for automatic output creation
self.addParameter(p, True)
def defineCharacteristicsFromFile(self):
"""
Create algorithm parameters and outputs from a text file.
"""
with open(self.descriptionFile) as lines:
# First line of the file is the Grass algorithm name
line = lines.readline().strip('\n').strip()
self.grass7Name = line
# Second line if the algorithm name in Processing
line = lines.readline().strip('\n').strip()
self._name = line
self._display_name = QCoreApplication.translate("GrassAlgorithm", line)
if " - " not in self._name:
self._name = self.grass7Name + " - " + self._name
self._display_name = self.grass7Name + " - " + self._display_name
self._name = self._name[:self._name.find(' ')].lower()
# Read the grass group
line = lines.readline().strip('\n').strip()
self._group = QCoreApplication.translate("GrassAlgorithm", line)
hasRasterOutput = False
hasVectorInput = False
vectorOutputs = False
# Then you have parameters/output definition
line = lines.readline().strip('\n').strip()
while line != '':
try:
line = line.strip('\n').strip()
if line.startswith('Hardcoded'):
self.hardcodedStrings.append(line[len('Hardcoded|'):])
parameter = getParameterFromString(line)
if parameter is not None:
self.params.append(parameter)
if isinstance(parameter, QgsProcessingParameterVectorLayer):
hasVectorInput = True
elif isinstance(parameter, QgsProcessingParameterMultipleLayers) \
and parameter.layerType() < 3:
hasVectorInput = True
elif isinstance(parameter, QgsProcessingParameterVectorDestination):
vectorOutputs = True
elif isinstance(parameter, QgsProcessingParameterRasterDestination):
hasRasterOutput = True
line = lines.readline().strip('\n').strip()
except Exception as e:
QgsMessageLog.logMessage(self.tr('Could not open GRASS GIS 7 algorithm: {0}\n{1}').format(self.descriptionFile, line), self.tr('Processing'), QgsMessageLog.CRITICAL)
raise e
param = QgsProcessingParameterExtent(
self.GRASS_REGION_EXTENT_PARAMETER,
self.tr('GRASS GIS 7 region extent'),
optional=True
)
param.setFlags(param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
self.params.append(param)
if hasRasterOutput:
param = QgsProcessingParameterNumber(
self.GRASS_REGION_CELLSIZE_PARAMETER,
self.tr('GRASS GIS 7 region cellsize (leave 0 for default)'),
type=QgsProcessingParameterNumber.Double,
minValue=0.0, maxValue=sys.float_info.max + 1, defaultValue=0.0
)
param.setFlags(param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
self.params.append(param)
if hasVectorInput:
param = QgsProcessingParameterNumber(self.GRASS_SNAP_TOLERANCE_PARAMETER,
self.tr('v.in.ogr snap tolerance (-1 = no snap)'),
type=QgsProcessingParameterNumber.Double,
minValue=-1.0, maxValue=sys.float_info.max + 1,
defaultValue=-1.0)
param.setFlags(param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
self.params.append(param)
param = QgsProcessingParameterNumber(self.GRASS_MIN_AREA_PARAMETER,
self.tr('v.in.ogr min area'),
type=QgsProcessingParameterNumber.Double,
minValue=0.0, maxValue=sys.float_info.max + 1,
defaultValue=0.0001)
param.setFlags(param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
self.params.append(param)
if vectorOutputs:
param = QgsProcessingParameterEnum(self.GRASS_OUTPUT_TYPE_PARAMETER,
self.tr('v.out.ogr output type'),
self.OUTPUT_TYPES)
param.setFlags(param.flags() | QgsProcessingParameterDefinition.FlagAdvanced)
self.params.append(param)
def getDefaultCellSize(self, parameters, context):
"""
Determine a default cell size from all the raster layers.
"""
if self.cellSize:
return True
cellsize = 0
parameters = [p for p in self.parameterDefinitions()
if isinstance(p, (QgsProcessingParameterRasterLayer,
QgsProcessingParameterMultipleLayers))]
cz = lambda l, cellsize: max(cellsize, (l.extent().xMaximum() - l.extent().xMinimum()) / l.width())
for param in parameters:
paramName = param.name()
if isinstance(param, QgsProcessingParameterRasterLayer):
layer = self.parameterAsExtent(parameters, paramName, context)
cellsize = max(cellsize, (layer.extent().xMaximum() -
layer.extent().xMinimum()) /
layer.width())
#cellsize = cz(layer, cellsize)
elif isinstance(param, QgsProcessingParameterMultipleLayers):
layers = self.parameterAsLayerList(parameters, paramName, context)
for layer in layers:
if layer.type() == QgsMapLayer.RasterLayer:
#cellsize = cz(layer, cellsize)
cellsize = max(cellsize, (
layer.extent().xMaximum() -
layer.extent().xMinimum()) /
layer.width())
QgsMessageLog.logMessage('cellSize: {}'.format(cellsize), 'Grass7', QgsMessageLog.INFO)
if cellsize == 0:
return False
else:
self.cellSize = cellsize
return True
def grabDefaultGrassParameters(self, parameters, context):
"""
Imports default GRASS parameters (EXTENT, etc) into
object attributes for faster retrieving.
"""
# GRASS region extent
self.region = self.parameterAsExtent(parameters,
self.GRASS_REGION_EXTENT_PARAMETER,
context)
QgsMessageLog.logMessage('processAlgorithm self.region: {}'.format(self.region.isEmpty()), 'Grass7', QgsMessageLog.INFO)
# GRASS cell size
self.cellSize = self.parameterAsString(parameters,
self.GRASS_REGION_CELLSIZE_PARAMETER,
context)
# GRASS snap tolerance
self.snapTolerance = self.parameterAsDouble(parameters,
self.GRASS_SNAP_TOLERANCE_PARAMETER,
context)
# GRASS min area
self.minArea = self.parameterAsDouble(parameters,
self.GRASS_MIN_AREA_PARAMETER,
context)
# GRASS output type
self.outputType = self.parameterAsString(parameters,
self.GRASS_OUTPUT_TYPE_PARAMETER,
context)
# GRASS align to resolution
self.alignToResolution = self.parameterAsBool(parameters,
self.GRASS_REGION_ALIGN_TO_RESOLUTION,
context)
def processAlgorithm(self, parameters, context, feedback):
if system.isWindows():
path = Grass7Utils.grassPath()
if path == '':
raise QgsProcessingException(
self.tr('GRASS GIS 7 folder is not configured. Please '
'configure it before running GRASS GIS 7 algorithms.'))
# Create brand new commands lists
self.commands = []
self.outputCommands = []
self.exportedLayers = {}
# If GRASS session has been created outside of this algorithm then
# get the list of layers loaded in GRASS otherwise start a new
# session
existingSession = Grass7Utils.sessionRunning
if existingSession:
self.exportedLayers = Grass7Utils.getSessionLayers()
else:
Grass7Utils.startGrass7Session()
# Handle default GRASS parameters
self.grabDefaultGrassParameters(parameters, context)
# Handle ext functions for inputs/command/outputs
if self.module:
if hasattr(self.module, 'processInputs'):
func = getattr(self.module, 'processInputs')
func(self)
else:
self.processInputs(parameters, context)
if hasattr(self.module, 'processCommand'):
func = getattr(self.module, 'processCommand')
func(self)
else:
self.processCommand()
if hasattr(self.module, 'processOutputs'):
func = getattr(self.module, 'processOutputs')
func(self)
else:
self.processOutputs()
else:
self.processInputs(parameters, context)
self.processCommand(parameters, context)
self.processOutputs(parameters, context)
# Run GRASS
loglines = []
loglines.append(self.tr('GRASS GIS 7 execution commands'))
for line in self.commands:
feedback.pushCommandInfo(line)
loglines.append(line)
if ProcessingConfig.getSetting(Grass7Utils.GRASS_LOG_COMMANDS):
QgsMessageLog.logMessage("\n".join(loglines), self.tr('Processing'), QgsMessageLog.INFO)
Grass7Utils.executeGrass7(self.commands, feedback, self.outputCommands)
# TODO handle and detect outputHtml
#for out in self.destinationParameterDefinitions():
# if isinstance(out, QgsProcessingParameterOutputHTML):
# with open(self.getOutputFromName("rawoutput").value) as f:
# rawOutput = "".join(f.readlines())
# with open(out.value, "w") as f:
# f.write("<pre>%s</pre>" % rawOutput)
# If the session has been created outside of this algorithm, add
# the new GRASS GIS 7 layers to it otherwise finish the session
if existingSession:
Grass7Utils.addSessionLayers(self.exportedLayers)
else:
Grass7Utils.endGrass7Session()
# Return outputs map
outputs = {}
for outName in [o.name() for o in self.outputDefinitions()]:
if outName in parameters:
outputs[outName] = parameters[outName]
QgsMessageLog.logMessage('processAlgorithm end. outputs: {}'.format(outputs), 'Grass7', QgsMessageLog.INFO)
return outputs
def processInputs(self, parameters, context):
"""Prepare the GRASS import commands"""
inputLayers=[]
inputs = [p for p in self.parameterDefinitions()
if isinstance(p, (QgsProcessingParameterVectorLayer,
QgsProcessingParameterRasterLayer,
QgsProcessingParameterMultipleLayers))]
for param in inputs:
paramName = param.name()
# Raster inputs needs to be imported into temp GRASS DB
if isinstance(param, QgsProcessingParameterRasterLayer):
if not paramName in parameters:
continue
layer = self.parameterAsRasterLayer(parameters, paramName, context)
layerSrc = parameters[paramName]
# Check if the layer hasn't already been exported in, for
# example, previous GRASS calls in this session
if paramName in self.exportedLayers:
continue
else:
inputLayers.append(layer)
self.setSessionProjectionFromLayer(layer)
self.commands.append(self.exportRasterLayer(paramName, layerSrc))
# Vector inputs needs to be imported into temp GRASS DB
elif isinstance(param, QgsProcessingParameterVectorLayer):
if not paramName in parameters:
continue
layer = self.parameterAsVectorLayer(parameters, paramName, context)
layerSrc = self.parameterAsCompatibleSourceLayerPath(
parameters, paramName, context,
self.provider().supportedOutputVectorLayerExtensions()
)
if paramName in self.exportedLayers:
continue
else:
inputLayers.append(layer)
self.setSessionProjectionFromLayer(layer)
self.commands.append(self.exportVectorLayer(paramName, layerSrc))
# TODO: find the best replacement for ParameterTable
#if isinstance(param, ParameterTable):
# pass
elif isinstance(param, QgsProcessingParameterMultipleLayers):
if not paramName in parameters:
continue
layers = self.parameterAsLayerList(parameters, paramName, context)
for idx, layer in enumerate(layers):
layerName = '{}_{}'.format(paramName, idx)
layerSrc = layer.source()
if layerName not in self.exportedLayers:
inputLayers.append(layer)
self.setSessionProjectionFromLayer(layer)
# Add a raster layer
if layer.type() == QgsMapLayer.RasterLayer:
self.commands.append(self.exportRasterLayer(layerName, layerSrc))
# Add a vector layer
elif layer.type() == QgsMapLayer.VectorLayer:
self.commands.append(self.exportVectorLayer(layerName, layerSrc))
# If projection has not already be set, use the project
self.setSessionProjectionFromProject()
# Build GRASS region
if self.region.isEmpty():
self.region = QgsProcessingUtils.combineLayerExtents(inputLayers)
command = 'g.region n={} s={} e={} w={}'.format(
self.region.yMaximum(), self.region.yMinimum(),
self.region.xMaximum(), self.region.xMinimum()
)
# Handle cell size
if self.getDefaultCellSize(parameters, context):
command += ' res={}'.format(self.cellSize)
# Handle align to resolution
if self.alignToResolution:
command += ' -a'
# Add the default parameters commands
self.commands.append(command)
QgsMessageLog.logMessage('processInputs end. Commands: {}'.format(self.commands), 'Grass7', QgsMessageLog.INFO)
def processCommand(self, parameters, context):
"""Prepare the GRASS algorithm command
:param parameters:
"""
noOutputs = [o for o in self.parameterDefinitions() if o not in self.destinationParameterDefinitions()]
command = '{} '.format(self.grass7Name)
command += '{}'.join(self.hardcodedStrings)
# Add algorithm command
for param in noOutputs:
paramName = param.name()
value = None
# Exclude default GRASS parameters
if paramName in [self.GRASS_REGION_CELLSIZE_PARAMETER,
self.GRASS_REGION_EXTENT_PARAMETER,
self.GRASS_MIN_AREA_PARAMETER,
self.GRASS_SNAP_TOLERANCE_PARAMETER,
self.GRASS_OUTPUT_TYPE_PARAMETER,
self.GRASS_REGION_ALIGN_TO_RESOLUTION]:
continue
# Raster and vector layers
if isinstance(param, (QgsProcessingParameterRasterLayer,
QgsProcessingParameterVectorLayer)):
if paramName in self.exportedLayers:
value = self.exportedLayers[paramName]
else:
value = self.parameterAsCompatibleSourceLayerPath(
parameters, paramName, context,
QgsVectorFileWriter.supportedFormatExtensions()
)
# MultipleLayers
elif isinstance(param, QgsProcessingParameterMultipleLayers):
layers = self.parameterAsLayerList(parameters, paramName, context)
values = []
for idx in range(len(layers)):
layerName = '{}_{}'.format(paramName, idx)
values.append(self.exportedLayers[layerName])
value = ','.join(values)
# For booleans, we just add the parameter name
elif isinstance(param, QgsProcessingParameterBoolean):
if self.parameterAsBool(parameters, paramName, context):
command += ' {}'.format(paramName)
# For enumeration, we need to grab the string value
elif isinstance(param, QgsProcessingParameterEnum):
idx = self.parameterAsEnum(parameters, paramName, context)
value = '"{}"'.format(param.options()[idx])
# For strings, we just translate as string
elif isinstance(param, QgsProcessingParameterString):
value = '"{}"'.format(
self.parameterAsString(parameters, paramName, context)
)
# For numbers and points, we translate as a string
elif isinstance(param, (QgsProcessingParameterNumber,
QgsProcessingParameterPoint)):
value = self.parameterAsString(parameters, paramName, context)
# For everything else, we assume that it is a string
else:
value = '"{}"'.format(
self.parameterAsString(parameters, paramName, context)
)
if value:
command += ' {}={}'.format(paramName, value)
# Handle outputs
for out in self.destinationParameterDefinitions():
outName = out.name()
# For File destination
if isinstance(out, QgsProcessingParameterFileDestination):
command += ' {}="{}"'.format(outName,
self.parameterAsFileOutput(parameters, outName, context))
else:
# We add an output name to make sure it is unique if the session
# uses this algorithm several times.
#value = self.parameterAsOutputLayer(parameters, outName, context)
uniqueOutputName = outName + self.uniqueSuffix
command += ' {}={}'.format(outName, uniqueOutputName)
# Add output file to exported layers, to indicate that
# they are present in GRASS
self.exportedLayers[outName] = uniqueOutputName
command += ' --overwrite'
self.commands.append(command)
QgsMessageLog.logMessage('processCommands end. Commands: {}'.format(self.commands), 'Grass7', QgsMessageLog.INFO)
def processOutputs(self, parameters, context):
"""Prepare the GRASS v.out.ogr commands"""
# TODO: support multiple raster formats.
# TODO: support multiple vector formats.
for out in self.destinationParameterDefinitions():
outName = out.name()
fileName = self.parameterAsOutputLayer(parameters, outName, context)
uniqName = '{}{}'.format(outName, self.uniqueSuffix)
if isinstance(out, QgsProcessingParameterRasterDestination):
# Raster layer output: adjust region to layer before
# exporting
self.commands.append('g.region raster={}'.format(uniqName))
self.outputCommands.append('g.region raster={}'.format(uniqName))
# TODO: move this hack into ext/
if self.grass7Name == 'r.statistics':
# r.statistics saves its results in a non-qgis compatible
# way. Post-process them with r.mapcalc.
calcExpression = 'correctedoutput' + self.uniqueSuffix
calcExpression += '=@{}'.format(uniqName)
command = 'r.mapcalc expression="' + calcExpression + '"'
self.commands.append(command)
self.outputCommands.append(command)
command = 'r.out.gdal --overwrite -c createopt="TFW=YES,COMPRESS=LZW"'
command += ' input='
command += 'correctedoutput' + self.uniqueSuffix
command += ' output="' + fileName + '"'
else:
command = 'r.out.gdal --overwrite -c createopt="TFW=YES,COMPRESS=LZW"'
command += ' input='
if self.grass7Name == 'r.horizon':
command += '{}_0'.format(uniqName)
elif self.grass7Name == 'r.statistics':
self.commands.append(command)
self.outputCommands.append(command)
else:
command += '{} output="{}"'.format(uniqName, fileName)
self.commands.append(command)
self.outputCommands.append(command)
if isinstance(out, QgsProcessingParameterVectorDestination):
typeidx = self.parameterAsEnum(parameters, self.GRASS_OUTPUT_TYPE_PARAMETER, context)
outType = ('auto' if typeidx
is None else self.OUTPUT_TYPES[typeidx])
# TODO: move this hack into ext/
if self.grass7Name == 'r.flow':
command = 'v.out.ogr type=line layer=0 -s -e input={}'.format(uniqName)
elif self.grass7Name == 'v.voronoi':
if '-l' in self.commands[-1]:
command = 'v.out.ogr type=line layer=0 -s -e input={}'.format(uniqName)
else:
command = 'v.out.ogr -s -e input={} type={}'.format(uniqName, outType)
elif self.grass7Name == 'v.sample':
command = 'v.out.ogr type=point -s -e input={}'.format(uniqName)
else:
command = 'v.out.ogr -s -e input={} type={}'.format(uniqName, outType)
command += ' output="{}"'.format(os.path.dirname(fileName))
command += ' format=ESRI_Shapefile'
command += ' output_layer={} --overwrite'.format(os.path.basename(fileName)[:-4])
self.commands.append(command)
self.outputCommands.append(command)
QgsMessageLog.logMessage('processOutputs. Commands: {}'.format(self.commands), 'Grass7', QgsMessageLog.INFO)
def exportVectorLayer(self, layerKey, layerSrc):
# TODO: learn about ProcessingContexts
#context = dataobjects.createContext()
# TODO: improve this. We are now exporting if it is not a shapefile,
# but the functionality of v.in.ogr could be used for this.
# We also export if there is a selection
#if not os.path.exists(orgFilename) or not orgFilename.endswith('shp'):
# layer = QgsProcessingUtils.mapLayerFromString(orgFilename, context, False)
# if layer:
# filename = dataobjects.exportVectorLayer(layer)
#else:
# layer = QgsProcessingUtils.mapLayerFromString(orgFilename, context, False)
# if layer:
# #TODO
# #useSelection = \
# # ProcessingConfig.getSetting(ProcessingConfig.USE_SELECTED)
# if useSelection and layer.selectedFeatureCount() != 0:
# filename = dataobjects.exportVectorLayer(layer)
# else:
# filename = orgFilename
# else:
# filename = orgFilename
# TODO handle selection with a where_clause?
# TODO use v.external as an option!
destFileName = 'a' + os.path.basename(self.getTempFilename())
self.exportedLayers[layerKey] = destFileName
layerFileName= os.path.basename(layerSrc)
layerName = os.path.splitext(layerFileName)[0]
command = 'v.in.ogr min_area={0} snap={1} input="{2}" layer={3} output={4} --overwrite -o'.format(
self.minArea, self.snapTolerance,
os.path.dirname(layerSrc),
layerName,
destFileName)
return command
def setSessionProjectionFromProject(self):
"""
Set the projection from the project.
We creates a PROJ4 definition which is transmitted to Grass
"""
if not Grass7Utils.projectionSet and iface:
proj4 = iface.mapCanvas().mapSettings().destinationCrs().toProj4()
command = 'g.proj -c proj4="{}"'.format(proj4)
self.commands.append(command)
Grass7Utils.projectionSet = True
def setSessionProjectionFromLayer(self, layer):
"""
Set the projection from a QgsVectorLayer.
We creates a PROJ4 definition which is transmitted to Grass
"""
context = dataobjects.createContext()
if not Grass7Utils.projectionSet:
proj4 = str(layer.crs().toProj4())
command = 'g.proj -c proj4="{}"'.format(proj4)
self.commands.append(command)
Grass7Utils.projectionSet = True
def exportRasterLayer(self, layerKey, layerSrc):
"""
Creates a dedicated command to load a raster into
temporary GRASS DB.
"""
# TODO: handle multiple bands
destFilename = 'a' + os.path.basename(self.getTempFilename())
self.exportedLayers[layerKey] = destFilename
command = 'r.external input="{}" band=1 output={} --overwrite -o'.format(
layerSrc, destFilename)
return command
def getTempFilename(self):
# TODO Replace with QgsProcessingUtils generateTempFilename
return system.getTempFilename()
def canExecute(self):
message = Grass7Utils.checkGrass7IsInstalled()
return not message, message
def checkParameterValues(self, parameters, context):
if self.module:
if hasattr(self.module, 'checkParameterValuesBeforeExecuting'):
func = getattr(self.module, 'checkParameterValuesBeforeExecuting')
return func(self), None
return super(Grass7Algorithm, self).checkParameterValues(parameters, context)