216 lines
8.3 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
general.py
---------------------
Date : April 2013
Copyright : (C) 2013 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. *
* *
***************************************************************************
"""
__author__ = 'Victor Olaya'
__date__ = 'April 2013'
__copyright__ = '(C) 2013, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
from qgis.core import (QgsApplication,
QgsProcessingAlgorithm,
QgsProcessingParameterEnum,
QgsProcessingParameterFeatureSink,
QgsProcessingParameterVectorDestination,
QgsProcessingParameterRasterDestination,
QgsProcessingOutputLayerDefinition,
QgsProject)
from processing.core.Processing import Processing
from processing.gui.Postprocessing import handleAlgorithmResults
from processing.gui.AlgorithmDialog import AlgorithmDialog
from qgis.utils import iface
def algorithmHelp(id):
"""
Prints algorithm parameters with their types. Also
provides information about parameters and outputs,
and their acceptable values.
:param id: An algorithm's ID
:type id: str
"""
alg = QgsApplication.processingRegistry().algorithmById(id)
if alg is not None:
print('{} ({})\n'.format(alg.displayName(), alg.id()))
if alg.shortDescription():
print(alg.shortDescription() + '\n')
if alg.shortHelpString():
print(alg.shortHelpString() + '\n')
print('\n----------------')
print('Input parameters')
print('----------------')
for p in alg.parameterDefinitions():
print('\n{}: {}'.format(p.name(), p.description()))
print('\n\tParameter type:\t{}'.format(p.__class__.__name__))
if isinstance(p, QgsProcessingParameterEnum):
opts = []
for i, o in enumerate(p.options()):
opts.append('\t\t- {}: {}'.format(i, o))
print('\n\tAvailable values:\n{}'.format('\n'.join(opts)))
parameter_type = QgsApplication.processingRegistry().parameterType(p.type())
accepted_types = parameter_type.acceptedPythonTypes() if parameter_type is not None else []
if accepted_types:
opts = []
for t in accepted_types:
opts.append('\t\t- {}'.format(t))
print('\n\tAccepted data types:')
print('\n'.join(opts))
print('\n----------------')
print('Outputs')
print('----------------')
for o in alg.outputDefinitions():
print('\n{}: <{}>'.format(o.name(), o.__class__.__name__))
if o.description():
print('\t' + o.description())
else:
print('Algorithm "{}" not found.'.format(id))
def run(algOrName, parameters, onFinish=None, feedback=None, context=None, is_child_algorithm=False):
"""
Executes given algorithm and returns its outputs as dictionary object.
:param algOrName: Either an instance of an algorithm, or an algorithm's ID
:param parameters: Algorithm parameters dictionary
:param onFinish: optional function to run after the algorithm has completed
:param feedback: Processing feedback object
:param context: Processing context object
:param is_child_algorithm: Set to True if this algorithm is being run as part of a larger algorithm,
i.e. it is a sub-part of an algorithm which calls other Processing algorithms.
:returns algorithm results as a dictionary, or None if execution failed
:rtype: Union[dict, None]
"""
if onFinish or not is_child_algorithm:
return Processing.runAlgorithm(algOrName, parameters, onFinish, feedback, context)
else:
# for child algorithms, we disable to default post-processing step where layer ownership
# is transferred from the context to the caller. In this case, we NEED the ownership to remain
# with the context, so that further steps in the algorithm have guaranteed access to the layer.
def post_process(_alg, _context, _feedback):
return
return Processing.runAlgorithm(algOrName, parameters, onFinish=post_process, feedback=feedback, context=context)
def runAndLoadResults(algOrName, parameters, feedback=None, context=None):
"""
Executes given algorithm and load its results into the current QGIS project
when possible.
:param algOrName: Either an instance of an algorithm, or an algorithm's ID
:param parameters: Algorithm parameters dictionary
:param feedback: Processing feedback object
:param context: Processing context object
:returns algorithm results as a dictionary, or None if execution failed
:rtype: Union[dict, None]
"""
if isinstance(algOrName, QgsProcessingAlgorithm):
alg = algOrName
else:
alg = QgsApplication.processingRegistry().createAlgorithmById(algOrName)
# output destination parameters to point to current project
for param in alg.parameterDefinitions():
if not param.name() in parameters:
continue
if isinstance(param, (QgsProcessingParameterFeatureSink, QgsProcessingParameterVectorDestination,
QgsProcessingParameterRasterDestination)):
p = parameters[param.name()]
if not isinstance(p, QgsProcessingOutputLayerDefinition):
parameters[param.name()] = QgsProcessingOutputLayerDefinition(p, QgsProject.instance())
else:
p.destinationProject = QgsProject.instance()
parameters[param.name()] = p
return Processing.runAlgorithm(alg, parameters=parameters, onFinish=handleAlgorithmResults, feedback=feedback,
context=context)
def createAlgorithmDialog(algOrName, parameters={}):
"""
Creates and returns an algorithm dialog for the specified algorithm, prepopulated
with a given set of parameters. It is the caller's responsibility to execute
and delete this dialog.
:param algOrName: Either an instance of an algorithm, or an algorithm's ID
:param parameters: Initial algorithm parameters dictionary
:returns algorithm results as a dictionary, or None if execution failed
:rtype: Union[dict, None]
"""
if isinstance(algOrName, QgsProcessingAlgorithm):
alg = algOrName.create()
else:
alg = QgsApplication.processingRegistry().createAlgorithmById(algOrName)
if alg is None:
return False
dlg = alg.createCustomParametersWidget(iface.mainWindow())
if not dlg:
dlg = AlgorithmDialog(alg, parent=iface.mainWindow())
dlg.setParameters(parameters)
return dlg
def execAlgorithmDialog(algOrName, parameters={}):
"""
Executes an algorithm dialog for the specified algorithm, prepopulated
with a given set of parameters.
:param algOrName: Either an instance of an algorithm, or an algorithm's ID
:param parameters: Initial algorithm parameters dictionary
:returns algorithm results as a dictionary, or None if execution failed
:rtype: Union[dict, None]
"""
dlg = createAlgorithmDialog(algOrName, parameters)
if dlg is None:
return {}
canvas = iface.mapCanvas()
prevMapTool = canvas.mapTool()
dlg.show()
dlg.exec_()
if canvas.mapTool() != prevMapTool:
try:
canvas.mapTool().reset()
except:
pass
canvas.setMapTool(prevMapTool)
results = dlg.results()
# make sure the dialog is destroyed and not only hidden on pressing Esc
dlg.close()
return results