def check_save(sender, **kwargs):
"""
Checks item type uniqueness, field applicability and multiplicity.
"""
tag = kwargs['instance']
obj = Tag.get_object(tag)
previous_tags = Tag.get_tags(obj)
err_uniq = check_item_type_uniqueness(tag, previous_tags)
err_appl = check_field_applicability(tag)
err_mult = check_field_multiplicity(tag, previous_tags)
err_msg = generate_error_message(tag, err_uniq, err_appl, err_mult)
if err_uniq or err_appl or err_mult:
raise TypeError(err_msg)
def delete_tags(sender, **kwargs):
"""
Delete the tags pointing to an object.
"""
try:
obj = kwargs.get('instance')
tags = Tag.get_tags(obj)
tags.delete()
except AttributeError:
pass
def render_meta(obj, vocabulary):
result = u'<link rel="schema.dc" href="http://purl.org/dc/elements/1.1/">'
tags = Tag.get_tags(obj)
if tags:
value = tags[0].item_type.type_name
meta_tag = u'<meta property="DC.type" content="%s"/>' % value
result = u'%s\n%s' % (result, meta_tag)
for tag in tags:
field = tag.field
name = field.namespaces.get(vocabulary, field.field_name)
value = tag.value
meta_tag = u'<meta property="DC.%s" content="%s"/>' % (name, value)
result = u'%s\n%s' % (result, meta_tag)
return result
