Move link-autogeneration from submission form to model and disable frontend editing

This ensures that it is always called when new AKs are created.
Additionally, editing of links in frontend is disabled, preventing diverging links between our tool and the wiki export.
This fixes #193 and #204.

AKModel/models.py

@@ -317,7 +317,7 @@ class AK(models.Model):
     owners = models.ManyToManyField(to=AKOwner, blank=True, verbose_name=_('Owners'),
                                     help_text=_('Those organizing the AK'))
 
-    # TODO generate automatically
+    # Will be automatically generated in save method if not set
     link = models.URLField(blank=True, verbose_name=_('Web Link'), help_text=_('Link to wiki page'))
     protocol_link = models.URLField(blank=True, verbose_name=_('Protocol Link'), help_text=_('Link to protocol'))
 
@@ -466,6 +466,17 @@ class AK(models.Model):
             return reverse_lazy('submit:ak_detail', kwargs={'event_slug': self.event.slug, 'pk': self.id})
         return self.edit_url
 
+    def save(self, force_insert=False, force_update=False, using=None, update_fields=None):
+        # Auto-Generate Link if not set yet
+        if self.link == "":
+            link = self.event.base_url + self.name.replace(" ", "_")
+            # Truncate links longer than 200 characters (default length of URL fields in django)
+            self.link = link[:200]
+            # Tell Django that we have updated the link field
+            if update_fields is not None:
+                update_fields = {"link"}.union(update_fields)
+        super().save(force_insert, force_update, using, update_fields)
+
 
 class Room(models.Model):
     """ A room describes where an AK can be held.

AKSubmission/forms.py

@@ -33,7 +33,6 @@ class AKForm(AvailabilitiesFormMixin, forms.ModelForm):
         model = AK
         fields = ['name',
                   'short_name',
-                  'link',
                   'protocol_link',
                   'owners',
                   'description',
@@ -101,7 +100,7 @@ class AKForm(AvailabilitiesFormMixin, forms.ModelForm):
         """
         Normalize/clean inputs
 
-        Generate a (not yet used) short name if field was left blank, generate a wiki link,
+        Generate a (not yet used) short name if field was left blank,
         create a list of normalized slot durations
 
         :return: cleaned inputs
@@ -128,12 +127,6 @@ class AKForm(AvailabilitiesFormMixin, forms.ModelForm):
                 short_name = f'{short_name[:-(digits + 1)]}-{i}'
             cleaned_data["short_name"] = short_name
 
-        # Generate wiki link
-        if self.cleaned_data["event"].base_url:
-            link = self.cleaned_data["event"].base_url + self.cleaned_data["name"].replace(" ", "_")
-            # Truncate links longer than 200 characters (default length of URL fields in django)
-            self.cleaned_data["link"] = link[:200]
-
         # Get durations from raw durations field
         if "durations" in cleaned_data:
             cleaned_data["durations"] = [self._clean_duration(d) for d in self.cleaned_data["durations"].split()]