Introduce a middleware that allows for HttpResponses to be thrown from inner utility functions, to avoid boilerplate in views

entries/from_url.py

@@ -1,35 +1,35 @@
-from typing import Union
 from urllib.parse import urlparse
 
 from django.contrib.sites.models import Site
 from django.http import HttpResponse
 from django.urls import resolve, Resolver404
 from micropub.views import error
+from lemoncurry.middleware import ResponseException
 
 from .models import Entry
 
 
-def from_url(url: str) -> Union[Entry, HttpResponse]:
+def from_url(url: str) -> Entry:
     domain = Site.objects.get_current().domain
     if not url:
-        return error.bad_req('url parameter required')
+        raise ResponseException(error.bad_req('url parameter required'))
     if '//' not in url:
         url = '//' + url
     parts = urlparse(url, scheme='https')
     if parts.scheme not in ('http', 'https') or parts.netloc != domain:
-        return error.bad_req('url does not point to this site')
+        raise ResponseException(error.bad_req('url does not point to this site'))
 
     try:
         match = resolve(parts.path)
     except Resolver404:
-        return error.bad_req('url does not point to a valid page on this site')
+        raise ResponseException(error.bad_req('url does not point to a valid page on this site'))
 
     if match.view_name != 'entries:entry':
-        return error.bad_req('url does not point to an entry on this site')
+        raise ResponseException(error.bad_req('url does not point to an entry on this site'))
 
     try:
         entry = Entry.objects.get(pk=match.kwargs['id'])
     except Entry.DoesNotExist:
-        return error.bad_req('url does not point to an existing entry')
+        raise ResponseException(error.bad_req('url does not point to an existing entry'))
 
     return entry