mirror of
https://github.com/dnlbauer/django-signposting.git
synced 2026-09-10 22:15:30 +00:00
107 lines
3.5 KiB
Python
107 lines
3.5 KiB
Python
from typing import Callable
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from django.http import HttpRequest, HttpResponse
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from signposting import Signpost
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from bs4 import BeautifulSoup
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import json
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from django.utils.deprecation import MiddlewareMixin
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from django.conf import settings
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from .utils import jsonld_to_signposts
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class SignpostingMiddleware:
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def __init__(self, get_response: Callable[[HttpRequest], HttpResponse]):
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self.get_response = get_response
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def __call__(self, request: HttpRequest) -> HttpResponse:
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response = self.get_response(request)
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# no signposts on errors
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if response.status_code >= 400:
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return response
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if not hasattr(response, "_signposts"):
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return response
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self._add_signposts(response, response._signposts)
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return response
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def _add_signposts(self, response: HttpResponse, signposts: list[Signpost]):
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"""Adds signposting headers to the respones.
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params:
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response - the response object
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signposts - a list of Signposts
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"""
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link_snippets = []
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for signpost in signposts:
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link_snippets.append(f'<{signpost.target}> ; rel="{signpost.rel}"')
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if signpost.type:
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link_snippets[-1] += f' ; type="{signpost.type}"'
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response["Link"] = " , ".join(link_snippets)
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class HtmlSignpostingMiddleware(SignpostingMiddleware):
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def __init__(self, get_response: Callable[[HttpRequest], HttpResponse]):
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self.get_response = get_response
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def __call__(self, request: HttpRequest) -> HttpResponse:
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response = self.get_response(request)
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if not hasattr(response, "_signposts"):
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return response
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# Adding Signposts via HTML is only supported for HTML responses
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if not response.headers["Content-Type"].startswith("text/html"):
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return response
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content = response.content.decode("utf-8")
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soup = BeautifulSoup(content, "html.parser")
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# Html should have a root element
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if not soup.html:
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raise Exception("Could not find HTML root element")
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# Add head element if not present
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if not soup.head:
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head_tag = soup.new_tag("head")
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soup.html.insert(0, head_tag)
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# BUild links for each signpost and add them to the html
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for signpost in response._signposts:
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link_tag = soup.new_tag("link")
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link_tag["rel"] = signpost.rel
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link_tag["href"] = signpost.target
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if signpost.type:
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link_tag["type"] = signpost.type
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soup.head.append(link_tag)
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# Override the original content with the new HTML
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response.content = soup.prettify().encode("utf-8")
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response["Content-Length"] = len(response.content)
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return response
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class JsonLdSignpostingParserMiddleware(MiddlewareMixin):
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def process_response(
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self, request: HttpRequest, response: HttpResponse
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) -> HttpResponse:
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if not getattr(settings, "SIGNPOSTING_PARSE_JSONLD", True):
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return response
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if response.get("Content-Type", "").startswith("text/html"):
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soup = BeautifulSoup(response.content, "html.parser")
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for script in soup.find_all("script", type="application/ld+json"):
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try:
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jsonld = json.loads(script.string)
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signposts = jsonld_to_signposts(jsonld)
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response._signposts = signposts
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except json.JSONDecodeError as e:
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print(e)
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continue
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return response
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