def parse(self, data, _format=None):
'''
Parses and RDF graph serialization and into the class graph
It calls the rdflib parse function with the provided data and format.
Data is a string with the serialized RDF graph (eg RDF/XML, N3
... ). By default RF/XML is expected. The optional parameter _format
can be used to tell rdflib otherwise.
It raises a ``RDFParserException`` if there was some error during
the parsing.
Returns nothing.
'''
_format = url_to_rdflib_format(_format)
if _format == 'pretty-xml':
_format = 'xml'
try:
self.g.parse(data=data, format=_format)
# Apparently there is no single way of catching exceptions from all
# rdflib parsers at once, so if you use a new one and the parsing
# exceptions are not cached, add them here.
# PluginException indicates that an unknown format was passed.
except (SyntaxError, xml.sax.SAXParseException,
rdflib.plugin.PluginException, TypeError), e:
raise RDFParserException(e)
def serialize_catalog(self,
catalog_dict=None,
dataset_dicts=None,
_format='xml',
pagination_info=None):
'''
Returns an RDF serialization of the whole catalog
`catalog_dict` can contain literal values for the dcat:Catalog class
like `title`, `homepage`, etc. If not provided these would get default
values from the CKAN config (eg from `ckan.site_title`).
If passed a list of CKAN dataset dicts, these will be also serializsed
as part of the catalog.
**Note:** There is no hard limit on the number of datasets at this
level, this should be handled upstream.
The serialization format can be defined using the `_format` parameter.
It must be one of the ones supported by RDFLib, defaults to `xml`.
`pagination_info` may be a dict containing keys describing the results
pagination. See the `_add_pagination_triples()` method for details.
Returns a string with the serialized catalog
'''
catalog_ref = self.graph_from_catalog(catalog_dict)
if dataset_dicts:
i = 0
publishers = {}
formats = {}
themes = dhh.dge_harvest_dict_theme_option_label()
for dataset_dict in dataset_dicts:
#Add available resource formats in catalog and publishers
dataset_dict[dhc.EXPORT_AVAILABLE_RESOURCE_FORMATS] = formats
dataset_dict[dhc.EXPORT_AVAILABLE_PUBLISHERS] = publishers
dataset_dict[dhc.EXPORT_AVAILABLE_THEMES] = themes
dataset_ref = self.graph_from_dataset(dataset_dict)
publishers = dataset_dict.get(dhc.EXPORT_AVAILABLE_PUBLISHERS,
{})
formats = dataset_dict.get(
dhc.EXPORT_AVAILABLE_RESOURCE_FORMATS, {})
i = i + 1
self.g.add((catalog_ref, DCAT.dataset, dataset_ref))
log.debug("[processors] serialize_catalog Total datasets i=%s", i)
self.g.add((catalog_ref, DCT.extent,
Literal(i, datatype=XSD.nonNegativeInteger)))
if pagination_info:
self._add_pagination_triples(pagination_info)
_format = url_to_rdflib_format(_format)
output = self.g.serialize(format=_format)
return output
def serialize_catalog(self, catalog_dict=None, dataset_dicts=None,
_format='xml', pagination_info=None):
'''
Returns an RDF serialization of the whole catalog
`catalog_dict` can contain literal values for the dcat:Catalog class
like `title`, `homepage`, etc. If not provided these would get default
values from the CKAN config (eg from `ckan.site_title`).
If passed a list of CKAN dataset dicts, these will be also serializsed
as part of the catalog.
**Note:** There is no hard limit on the number of datasets at this
level, this should be handled upstream.
The serialization format can be defined using the `_format` parameter.
It must be one of the ones supported by RDFLib, defaults to `xml`.
`pagination_info` may be a dict containing keys describing the results
pagination. See the `_add_pagination_triples()` method for details.
Returns a string with the serialized catalog
'''
catalog_ref = self.graph_from_catalog(catalog_dict)
if dataset_dicts:
for dataset_dict in dataset_dicts:
dataset_ref = self.graph_from_dataset(dataset_dict)
cat_ref = self._add_source_catalog(catalog_ref, dataset_dict, dataset_ref)
if not cat_ref:
self.g.add((catalog_ref, DCAT.dataset, dataset_ref))
if pagination_info:
self._add_pagination_triples(pagination_info)
if not _format:
_format = 'xml'
_format = url_to_rdflib_format(_format)
#print _format
output = self.g.serialize(format=_format)
#print "serialize catalog**********"
#print output
return output
def serialize_dataset(self, dataset_dict, _format='xml'):
'''
Given a CKAN dataset dict, returns an RDF serialization
The serialization format can be defined using the `_format` parameter.
It must be one of the ones supported by RDFLib, defaults to `xml`.
Returns a string with the serialized dataset
'''
self.graph_from_dataset(dataset_dict)
_format = url_to_rdflib_format(_format)
if _format == 'json-ld':
output = self.g.serialize(format=_format, auto_compact=True)
else:
output = self.g.serialize(format=_format)
return output
def serialize_record(self, record_dict, resource_dict, _format="xml"):
"""
Given a CKAN dataset dict, returns an RDF serialization
The serialization format can be defined using the `_format` parameter.
It must be one of the ones supported by RDFLib, defaults to `xml`.
Returns a string with the serialized dataset
"""
self.graph_from_record(record_dict, resource_dict)
_format = url_to_rdflib_format(_format)
if _format == "json-ld":
output = self.g.serialize(format=_format, auto_compact=True)
else:
output = self.g.serialize(format=_format)
return output
def serialize_catalog(self, catalog_dict=None, dataset_dicts=None,
_format='xml', pagination_info=None):
'''
Returns an RDF serialization of the whole catalog
`catalog_dict` can contain literal values for the dcat:Catalog class
like `title`, `homepage`, etc. If not provided these would get default
values from the CKAN config (eg from `ckan.site_title`).
If passed a list of CKAN dataset dicts, these will be also serializsed
as part of the catalog.
**Note:** There is no hard limit on the number of datasets at this
level, this should be handled upstream.
The serialization format can be defined using the `_format` parameter.
It must be one of the ones supported by RDFLib, defaults to `xml`.
`pagination_info` may be a dict containing keys describing the results
pagination. See the `_add_pagination_triples()` method for details.
Returns a string with the serialized catalog
'''
catalog_ref = self.graph_from_catalog(catalog_dict)
if dataset_dicts:
for dataset_dict in dataset_dicts:
dataset_ref = self.graph_from_dataset(dataset_dict)
cat_ref = self._add_source_catalog(catalog_ref, dataset_dict, dataset_ref)
if not cat_ref:
self.g.add((catalog_ref, DCAT.dataset, dataset_ref))
if pagination_info:
self._add_pagination_triples(pagination_info)
if not _format:
_format = 'xml'
_format = url_to_rdflib_format(_format)
output = self.g.serialize(format=_format)
return output
def serialize_record(self, record, resource, output_format=u'xml', version=None):
'''
Given a record dict, returns an RDF serialization.
The serialization format can be defined using the `_format` parameter. It must be one of the
ones supported by RDFLib, defaults to `xml`.
Returns a string with the serialized dataset
'''
rdflib_format = url_to_rdflib_format(output_format)
builder = RecordGraphBuilder(record, resource, Namespaces(self.g), output_format, version)
for triple in builder:
# the builder is allowed to yield duplicate triples so using add here just defers the
# handling of these to the triplestore itself, which it handles fine. We could use set
# to be more proactive with de-duplication, however the replace part of the set function
# removes all previously added subject-predicate pairs and is therefore too aggressive
# (i.e. set(x, y, a) followed by set(x, y, b) would result in (x, y, b) in the
# triplestore and the (x, y, a) triple would be removed)
self.g.add(triple)
return self.g.serialize(format=rdflib_format,
**self.serializer_kwargs.get(rdflib_format, {}))
