feat: move bibtex fetching to utils

The logic to fill the bibtex data is now part of the `utils` module and
can therefore be used in the `save()` method of the model as well as in
other places, like the api_views.py module.
The logic was copied from the api_views.SaveBibsonomyEntry.post() method
and refactored a bit. If there is any kind of error, the method simply
returns `None`.

apis_bibsonomy/api_views.py

@@ -10,7 +10,7 @@
 from rest_framework.views import APIView
 
 from .models import Reference
-from .utils import BibsonomyEntry
+from .utils import BibsonomyEntry, get_bibtex_from_url
 
 
 class SaveBibsonomyEntry(APIView):
@@ -37,29 +37,11 @@ def post(self, request, format=None):
         pages_end = request.data.get("pages_end", None)
         folio = request.data.get("folio", None)
         notes = request.data.get("notes", None)
-        kind = None
         sett = getattr(settings, "APIS_BIBSONOMY", [])
-        for s in sett:
-            if "url" in s.keys():
-                if s["url"] in bib_ref:
-                    sett1 = s
-                    kind = s["type"]
         if bib_ref is not None:
             r = {"bibs_url": bib_ref}
-            if kind == "bibsonomy":
-                bib_e = BibsonomyEntry(bib_hash=bib_ref, base_set=sett1)
-                r["bibtex"] = json.dumps(bib_e.bibtex)
-            elif kind == "zotero":
-                for s in sett:
-                    if s["type"] == "zotero":
-                        headers = {
-                            "Zotero-API-Key": s["API key"],
-                            "Zotero-API-Version": "3",
-                        }
-                        params = {"include": "csljson"}
-                        res = requests.get(bib_ref, headers=headers, params=params)
-                        r["bibtex"] = json.dumps(res.json()["csljson"])
-            else:
+            r["bibtex"] = get_bibtex_from_url(bib_ref)
+            if r["bibtex"] is None:
                 m = {"message": "You need to select a publication."}
                 return Response(data=m, status=status.HTTP_400_BAD_REQUEST)
         if obj_id is not None:

apis_bibsonomy/models.py

@@ -3,10 +3,12 @@
 from django.urls import reverse
 from django.conf import settings
 from django.db.models import Q
+from .utils import BibsonomyEntry, get_bibtex_from_url
+from django.conf import settings
+import requests
 
 import json
 
-
 class Reference(models.Model):
     """Model that holds the reference to a bibsonomy entry"""
 
@@ -51,3 +53,21 @@ def similar_references(self, with_self=False):
         if not with_self:
             return Reference.objects.exclude(pk=self.pk).filter(similarity)
         return Reference.objects.filter(similarity)
+
+
+
+    def save(
+        self, force_insert=False, force_update=False, using=None, update_fields=None
+    ):
+
+        if update_fields is not None and "bibtex" in update_fields:
+            self.bibtex = None
+        if self.bibtex is None and self.bibs_url is not None:
+            self.bibtex = get_bibtex_from_url(self.bibs_url)
+
+        super().save(
+            force_insert=force_insert,
+            force_update=force_update,
+            using=using,
+            update_fields=update_fields,
+        )

apis_bibsonomy/utils.py

@@ -3,6 +3,8 @@
 from requests.auth import HTTPBasicAuth
 from django.conf import settings
 import json
+import logging
+logger = logging.getLogger(__name__)
 
 
 class BibsonomyEntry:
@@ -51,3 +53,25 @@ def get_autocomplete(self):
         return res_str
     html = property(get_html)
     autocomplete = property(get_autocomplete)
+
+def get_bibtex_from_url(url):
+    sources = getattr(settings, "APIS_BIBSONOMY", [])
+    sources = [s for s in sources if s.get("url") and s.get("url") in url]
+    source = sources[-1]
+    btype = source.get("type", None)
+    bibtex = None
+    try:
+        if btype == "bibsonomy":
+            bib_e = BibsonomyEntry(bib_hash=url, base_set=source)
+            bibtex = json.dumps(bib_e.bibtex)
+        elif btype == "zotero":
+            headers = {
+                "Zotero-API-Key": source.get("API key", None),
+                "Zotero-API-Version": "3",
+            }
+            params = {"include": "csljson"}
+            res = requests.get(url, headers=headers, params=params)
+            bibtex = json.dumps(res.json()["csljson"])
+    except Exception as e:
+        logger.warning(f"Could not fetch bibtex from {url}: {e}")
+    return bibtex