Files
Daniel Bauer 6b1ea1403c Create Signposting from RO-Crate (#2)
* improvate jsonld parsing to be compatible with ro-crate

* refactoring

* example with RO-Crate

* bump version

---------

Co-authored-by: Daniel Bauer <daniel.bauer@senckenberg.de>
2024-11-21 15:40:46 +01:00

87 lines
2.6 KiB
Python

import json
from django.http import HttpResponse
from rdflib import Graph
from signposting import Signpost, LinkRel
import re
from django_signposting import sparql
def add_signposts(response: HttpResponse, *args: Signpost):
""" Adds signposting headers to the responses.
params:
response - the response object
args - a list of signposts to add to this resposnse.
"""
if not hasattr(response, '_signposts'):
response._signposts = []
for signpost in args:
if signpost not in response._signposts:
response._signposts.append(signpost)
def select_url(elements: tuple[str, ...]) -> str | None:
def is_url(url: str) -> bool:
url_pattern = re.compile(
r"^(https?|ftp)://" # protocol
r"(?:(?:[a-zA-Z0-9-_]+\.)?[a-zA-Z0-9-]+\.[a-zA-Z]{2,6})" # domain
r"(?::\d{1,5})?" # optional port
r"(?:/.*)?$" # path
)
return bool(url_pattern.match(url))
for elem in elements[::-1]:
if is_url(str(elem)):
return str(elem)
return None
def jsonld_to_signposts(jsonld: dict) -> []:
signposts = []
# TODO use jsonld context in query as prefix
g = Graph().parse(data=json.dumps(jsonld), format="json-ld")
rootElement = next(iter(sparql.root_element_query(g)), None)
if rootElement:
rootElement = rootElement[0]
else:
print("No root element found")
return {}
types = sparql.type_query(g, rootElement)
for type in types:
signposts.append(Signpost(LinkRel.type, str(type[0])))
authors = sparql.author_query(g, rootElement)
for author in authors:
author = select_url(author)
if author:
signposts.append(Signpost(LinkRel.author, author))
license = next(iter(sparql.license_query(g, rootElement)), [])
license = select_url(license)
if license:
signposts.append(Signpost(LinkRel.license, license))
citations = sparql.cite_query(g, rootElement)
for citation in citations:
citation = select_url(citation)
if citation:
signposts.append(Signpost(LinkRel.cite_as, citation))
sameas = sparql.sameas_query(g, rootElement)
for sa in sameas:
sa_media_type = sa[-1]
sa = select_url(sa[:-1])
if sa:
signposts.append(Signpost(LinkRel.describedby, sa, sa_media_type))
items = sparql.item_query(g, rootElement)
for item in items:
item_media_type = item[-1]
item = select_url(item[:-1])
if item:
signposts.append(Signpost(LinkRel.item, item, item_media_type))
return signposts