Source code for sylib.nodes.sympathy.data.json.importers.plugin_base_json_importers
# This file is part of Sympathy for Data.
# Copyright (c) 2018, Combine Control Systems AB
#
# Sympathy for Data 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, version 3 of the License.
#
# Sympathy for Data is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Sympathy for Data. If not, see <http://www.gnu.org/licenses/>.
import os
import io
import json
import xmltodict
from sympathy.api import importers
from sympathy.api.exceptions import SyDataError
from sympathy.api import qt as qt_compat
QtGui = qt_compat.import_module('QtGui')
def _sniff_type(filename):
"""
Guess if it is a JSON or XML file by looking
at the file extension or the first line
"""
ext = os.path.splitext(filename)[1].lower()
if ext in [".json", ".xml"]:
return ext[1:]
with open(filename, "rb") as f:
for line in f:
line = line.lstrip()
if line:
if line.startswith(b"<"):
return "xml"
else:
return "json"
def import_data(obj, filename, filetype):
"""
Load a Json structure from a datasource or a filepath
:param datasource: the datasource or the filepath to load the Json from
:param filetype: can be either ``json`` or ``xml`` and determines what type
of file to load
"""
filetype = filetype.lower()
with io.open(filename, "rb") as f:
if filetype == "json":
_dict = json.load(f)
elif filetype == "xml":
_dict = xmltodict.parse(f.read())
else:
assert False, 'Unknown filetype'
obj.set(_dict)
class DataImportAuto(importers.JsonDataImporterBase):
IMPORTER_NAME = "Auto"
def __init__(self, fq_infilename, parameters):
self.__importer_class = None
super(DataImportAuto, self).__init__(fq_infilename, parameters)
def _importer_class(self):
if self._fq_infilename is not None:
if self.__importer_class is None:
self.__importer_class = (
importers.plugin_for_file(
importers.JsonDataImporterBase,
self._fq_infilename))
return self.__importer_class
def valid_for_file(self):
return False
def is_type(self):
importer_class = self._importer_class()
if importer_class is None:
raise SyDataError(
"No importer could automatically be found for this file.")
importer = importer_class(self._fq_infilename, None)
return importer.is_type()
def parameter_view(self, parameters):
importer_class = self._importer_class()
if importer_class is None:
text = "No importer could automatically be found for this file."
else:
text = "This file will be imported using the {} importer.".format(
importer_class.display_name())
return QtGui.QLabel(text)
def import_data(self, out_datafile, parameters=None, progress=None):
importer_class = self._importer_class()
if importer_class is None:
raise SyDataError(
"No importer could automatically be found for this file.")
importer = importer_class(self._fq_infilename, parameters)
importer.import_data(out_datafile, parameters, progress)
[docs]class DataImportXml(importers.JsonDataImporterBase):
IMPORTER_NAME = "XML"
def valid_for_file(self):
try:
return _sniff_type(self._fq_infilename) == 'xml'
except Exception:
return False
def parameter_view(self, parameters):
if not self.valid_for_file():
return QtGui.QLabel(
'File does not exist or cannot be read.')
return QtGui.QLabel()
def import_data(self, out_datafile, parameters=None, progress=None):
import_data(out_datafile, self._fq_infilename, filetype='xml')
class DataImportJson(importers.JsonDataImporterBase):
IMPORTER_NAME = "JSON"
def valid_for_file(self):
try:
return _sniff_type(self._fq_infilename) == 'json'
except Exception:
return False
def parameter_view(self, parameters):
if not self.valid_for_file():
return QtGui.QLabel(
'File does not exist or cannot be read.')
return QtGui.QLabel()
def import_data(self, out_datafile, parameters=None, progress=None):
import_data(out_datafile, self._fq_infilename, filetype='json')