Properly handle tag without aliases (though don't know how this can happen)

boards/models/tag.py

@@ -1,201 +1,211 b''
 import hashlib
 from django.urls import reverse
 from django.db import models
 from django.db.models import Count, Q
 from django.utils.translation import get_language
 
 import boards
 from boards.models import Attachment
 from boards.models.attachment import FILE_TYPES_IMAGE
 from boards.models.base import Viewable
 from boards.models.thread import STATUS_ACTIVE, STATUS_BUMPLIMIT, STATUS_ARCHIVE
 from boards.utils import cached_result
 
 
 __author__ = 'neko259'
 
 
 TAG_DELIMITER = ', '
 RELATED_TAGS_COUNT = 5
 DEFAULT_LOCALE = 'default'
 
 
 class TagAliasManager(models.Manager):
     def filter_localized(self, *args, **kwargs):
         locale = get_language()
         tag_aliases = (self.filter(locale=locale)
                 | self.filter(Q(locale=DEFAULT_LOCALE)
                     & ~Q(parent__aliases__locale=locale)))
         return tag_aliases.filter(**kwargs)
 
 
 class TagAlias(models.Model, Viewable):
     class Meta:
         app_label = 'boards'
         ordering = ('name',)
         unique_together = ('name', 'locale')
 
     objects = TagAliasManager()
 
     name = models.CharField(max_length=100, db_index=True)
     locale = models.CharField(max_length=10, db_index=True)
 
     parent = models.ForeignKey('Tag', on_delete=models.CASCADE, null=True,
                                blank=True, related_name='aliases')
 
     def __str__(self):
         return self.name
 
 
 class TagManager(models.Manager):
     def get_tag_url_list(self, tags: list) -> str:
         """
         Gets a comma-separated list of tag links.
         """
 
         return TAG_DELIMITER.join([tag.get_view() for tag in tags])
 
     def get_by_alias(self, alias):
         try:
             return self.filter(aliases__name__in=[alias]).first()
         except Tag.DoesNotExist:
             pass
 
     def get_or_create_with_alias(self, name, required=False):
         tag = self.get_by_alias(name)
         created = False
         if not tag:
             tag = self.create(required=required)
             TagAlias.objects.create(name=name, locale=DEFAULT_LOCALE, parent=tag)
             created = True
         return tag, created
 
 
 class Tag(models.Model, Viewable):
     """
     A tag is a text node assigned to the thread. The tag serves as a board
     section. There can be multiple tags for each thread
     """
 
     objects = TagManager()
 
     class Meta:
         app_label = 'boards'
 
     required = models.BooleanField(default=False, db_index=True)
     description = models.TextField(blank=True)
 
     parent = models.ForeignKey('Tag', on_delete=models.CASCADE, null=True,
                                blank=True, related_name='children')
 
     def get_name(self):
-        return self.aliases.get(locale=DEFAULT_LOCALE).name
+        try:
+            alias = self.aliases.get(locale=DEFAULT_LOCALE)
+        except TagAlias.DoesNotExist:
+            alias = self.aliases.first()
+
+        if alias:
+            return alias.name
+        else:
+            # This is an extremely bad situation, somehow we have a tag without
+            # any alias
+            return 'BROKEN #{}'.format(self.id)
 
     def __str__(self):
         return self.get_name()
 
     def is_empty(self) -> bool:
         """
         Checks if the tag has some threads.
         """
 
         return self.get_thread_count() == 0
 
     def get_thread_count(self, status=None) -> int:
         threads = self.get_threads()
         if status is not None:
             threads = threads.filter(status=status)
         return threads.count()
 
     def get_active_thread_count(self) -> int:
         return self.get_thread_count(status=STATUS_ACTIVE)
 
     def get_bumplimit_thread_count(self) -> int:
         return self.get_thread_count(status=STATUS_BUMPLIMIT)
 
     def get_archived_thread_count(self) -> int:
         return self.get_thread_count(status=STATUS_ARCHIVE)
 
     @cached_result()
     def get_absolute_url(self):
         return reverse('tag', kwargs={'tag_name': self.get_name()})
 
     def get_threads(self):
         return self.thread_tags.order_by('-bump_time')
 
     def is_required(self):
         return self.required
 
     def _get_locale_cache_key(self):
         return [get_language()]
 
     @cached_result(key_method=_get_locale_cache_key)
     def get_localized_name(self):
         locale = get_language()
 
         aliases = self.aliases.filter(Q(locale=locale) | Q(locale=DEFAULT_LOCALE))
 
         localized_tag_name = None
         default_tag_name = None
 
         for alias in aliases:
             if alias.locale == locale:
                 localized_tag_name = alias.name
             elif alias.locale == DEFAULT_LOCALE:
                 default_tag_name = alias.name
 
         return localized_tag_name or default_tag_name
 
     def get_view(self):
         name = self.get_localized_name()
         link = '<a class="tag" href="{}">{}</a>'.format(
             self.get_absolute_url(), name)
         if self.is_required():
             link = '<b>{}</b>'.format(link)
         return link
 
     @cached_result()
     def get_post_count(self):
         return self.get_threads().aggregate(num_posts=Count('replies'))['num_posts']
 
     def get_description(self):
         return self.description
 
     def get_random_image_post(self, status=[STATUS_ACTIVE, STATUS_BUMPLIMIT]):
         posts = boards.models.Post.objects.filter(attachments__mimetype__in=FILE_TYPES_IMAGE)\
             .annotate(images_count=Count(
             'attachments')).filter(images_count__gt=0, thread__tags__in=[self])
         if status is not None:
             posts = posts.filter(thread__status__in=status)
         return posts.order_by('?').first()
 
     def get_related_tags(self):
         return set(Tag.objects.filter(thread_tags__in=self.get_threads()).exclude(
             id=self.id).order_by('?')[:RELATED_TAGS_COUNT])
 
     @cached_result()
     def get_color(self):
         """
         Gets color hashed from the tag name.
         """
         return hashlib.md5(self.get_name().encode()).hexdigest()[:6]
 
     def get_parent(self):
         return self.parent
 
     def get_all_parents(self):
         parents = list()
         parent = self.get_parent()
         if parent and parent not in parents:
             parents.insert(0, parent)
             parents = parent.get_all_parents() + parents
 
         return parents
 
     def get_children(self):
         return self.children
 
     def get_images(self):
         return Attachment.objects.filter(
             attachment_posts__thread__tags__in=[self]).filter(
             mimetype__in=FILE_TYPES_IMAGE).order_by('-attachment_posts__pub_time')