def create_topic_by_subject_locator (self, subject_locator):
"""Returns a `Topic` instance with the specified subject locator.
This method returns either an existing `Topic` or creates a
new `Topic` instance with the specified subject locator.
:param subject_locator: the subject locator the topic should
contain
:type subject_locator: `Locator`
:rtype: `Topic`
"""
if subject_locator is None:
raise ModelConstraintException(
self, 'The subject locator may not be None')
reference = subject_locator.to_external_form()
try:
topic = self.topic_constructs.get(
subject_locators__address=reference)
except Topic.DoesNotExist:
topic = Topic(topic_map=self)
topic.save()
sl = SubjectLocator(topic=topic, address=reference,
containing_topic_map=self)
sl.save()
topic.subject_locators.add(sl)
return topic
def create_topic_by_subject_locator(self, subject_locator):
"""Returns a `Topic` instance with the specified subject locator.
This method returns either an existing `Topic` or creates a
new `Topic` instance with the specified subject locator.
:param subject_locator: the subject locator the topic should
contain
:type subject_locator: `Locator`
:rtype: `Topic`
"""
if subject_locator is None:
raise ModelConstraintException(
self, 'The subject locator may not be None')
reference = subject_locator.to_external_form()
try:
topic = self.topic_constructs.get(
subject_locators__address=reference)
except Topic.DoesNotExist:
topic = Topic(topic_map=self)
topic.save()
sl = SubjectLocator(topic=topic,
address=reference,
containing_topic_map=self)
sl.save()
topic.subject_locators.add(sl)
return topic
def create_empty_topic (self):
"""Returns a `Topic` instance with no other information.
:rtype: `Topic`
"""
topic = Topic(topic_map=self)
topic.save()
return topic
def create_empty_topic(self):
"""Returns a `Topic` instance with no other information.
:rtype: `Topic`
"""
topic = Topic(topic_map=self)
topic.save()
return topic
def create_topic_by_subject_identifier(self, subject_identifier):
"""Returns a `Topic` instance with the specified subject identifier.
This method returns either an existing `Topic` or creates a
new `Topic` instance with the specified subject identifier.
If a topic with the specified subject identifier exists in
this topic map, that topic is returned. If a topic with an
item identifier equal to the specified subject identifier
exists, the specified subject identifier is added to that
topic and the topic is returned. If neither a topic with the
specified subject identifier nor with an item identifier equal
to the subject identifier exists, a topic with the subject
identifier is created.
:param subject_identifier: the subject identifier the topic
should contain
:type subject_identifier: `Locator`
:rtype: `Topic`
"""
if subject_identifier is None:
raise ModelConstraintException(
self, 'The subject identifier may not be None')
reference = subject_identifier.to_external_form()
try:
topic = self.topic_constructs.get(
subject_identifiers__address=reference)
except Topic.DoesNotExist:
try:
topic = self.topic_constructs.get(
item_identifiers__address=reference)
except Topic.DoesNotExist:
topic = Topic(topic_map=self)
topic.save()
si = SubjectIdentifier(topic=topic,
address=reference,
containing_topic_map=self)
si.save()
topic.subject_identifiers.add(si)
return topic
def create_topic_by_subject_identifier (self, subject_identifier):
"""Returns a `Topic` instance with the specified subject identifier.
This method returns either an existing `Topic` or creates a
new `Topic` instance with the specified subject identifier.
If a topic with the specified subject identifier exists in
this topic map, that topic is returned. If a topic with an
item identifier equal to the specified subject identifier
exists, the specified subject identifier is added to that
topic and the topic is returned. If neither a topic with the
specified subject identifier nor with an item identifier equal
to the subject identifier exists, a topic with the subject
identifier is created.
:param subject_identifier: the subject identifier the topic
should contain
:type subject_identifier: `Locator`
:rtype: `Topic`
"""
if subject_identifier is None:
raise ModelConstraintException(
self, 'The subject identifier may not be None')
reference = subject_identifier.to_external_form()
try:
topic = self.topic_constructs.get(
subject_identifiers__address=reference)
except Topic.DoesNotExist:
try:
topic = self.topic_constructs.get(
item_identifiers__address=reference)
except Topic.DoesNotExist:
topic = Topic(topic_map=self)
topic.save()
si = SubjectIdentifier(topic=topic, address=reference,
containing_topic_map=self)
si.save()
topic.subject_identifiers.add(si)
return topic