def start_app(gui=True, cleanup=True):
"""
Will start a QgsApplication and call all initialization code like
registering the providers and other infrastructure.
It will not load any plugins.
You can always get the reference to a running app by calling `QgsApplication.instance()`.
The initialization will only happen once, so it is safe to call this method repeatedly.
Parameters
----------
cleanup: Do cleanup on exit. Defaults to true.
Returns
-------
QgsApplication
A QgsApplication singleton
"""
global QGISAPP # pylint: disable=global-variable-undefined
try:
QGISAPP
except NameError:
# In python3 we need to convert to a bytes object (or should
# QgsApplication accept a QString instead of const char* ?)
try:
argvb = [os.fsencode(arg) for arg in sys.argv]
except AttributeError:
argvb = ['']
if platform.system() == 'Darwin':
QgsApplication.addLibraryPath(
os.path.expandvars('$QGIS_PREFIX_PATH/../Plugins'))
QgsApplication.addLibraryPath(
os.path.expandvars('$QGIS_PREFIX_PATH/../Plugins/qgis'))
QgsApplication.addLibraryPath(
os.path.expandvars('$QGIS_PREFIX_PATH/../MacOS'))
# Note: QGIS_PREFIX_PATH is evaluated in QgsApplication -
# no need to mess with it here.
QGISAPP = QgsApplication(argvb, gui)
QGISAPP.initQgis()
# click.echo(QGISAPP.showSettings())
Processing.initialize()
def debug_log_message(message, tag, level):
""" Print debug message on console """
click.secho('{}({}): {}'.format(tag, level, message), fg='yellow')
QgsApplication.instance().messageLog().messageReceived.connect(
debug_log_message)
if cleanup:
@atexit.register
def exitQgis(): # pylint: disable=unused-variable
""" Exit Qgis Application """
QGISAPP.exitQgis()
return QGISAPP
