def __init__(self, layer_uri, xml_uri=None, json_uri=None):
"""
Constructor.
:param layer_uri: uri of the layer for which the metadata ae
:type layer_uri: str
:param xml_uri: uri of an xml file to use
:type xml_uri: str
:param json_uri: uri of a json file to use
:type json_uri: str
"""
# private members
self._layer_uri = layer_uri
# TODO (MB): maybe use MetadataDbIO.are_metadata_file_based instead
self._layer_is_file_based = os.path.isfile(layer_uri)
instantiate_metadata_db = False
path = os.path.splitext(layer_uri)[0]
if xml_uri is None:
if self.layer_is_file_based:
self._xml_uri = '%s.xml' % path
else:
# xml should be stored in cacheDB
self._xml_uri = None
instantiate_metadata_db = True
else:
self._xml_uri = xml_uri
if json_uri is None:
if self.layer_is_file_based:
self._json_uri = '%s.json' % path
else:
# json should be stored in cacheDB
self._json_uri = None
instantiate_metadata_db = True
else:
self._json_uri = json_uri
if instantiate_metadata_db:
self.db_io = MetadataDbIO()
self.reading_ancillary_files = False
self._properties = {}
# initialise the properties
for name, path in self._standard_properties.iteritems():
self.set(name, None, path)
self._last_update = datetime.now()
try:
self.read_from_ancillary_file(xml_uri)
except IOError:
pass
