Merge pull request #2524 from chdorner/feature/tag-support

Initial hashtag support

bookwyrm/views/__init__.py

@@ -130,6 +130,7 @@ from .group import (
     accept_membership,
     reject_membership,
 )
+from .hashtag import Hashtag
 from .inbox import Inbox
 from .interaction import Favorite, Unfavorite, Boost, Unboost
 from .isbn import Isbn

bookwyrm/views/hashtag.py

@@ -0,0 +1,54 @@
+""" listing statuses for a given hashtag """
+from django.core.paginator import Paginator
+from django.db.models import Q
+from django.views import View
+from django.shortcuts import get_object_or_404
+from django.template.response import TemplateResponse
+
+from bookwyrm import models
+from bookwyrm.settings import PAGE_LENGTH
+from bookwyrm.views.helpers import maybe_redirect_local_path
+
+
+# pylint: disable= no-self-use
+class Hashtag(View):
+    """listing statuses for a given hashtag"""
+
+    # pylint: disable=unused-argument
+    def get(self, request, hashtag_id, slug=None):
+        """show hashtag with related statuses"""
+        hashtag = get_object_or_404(models.Hashtag, id=hashtag_id)
+
+        if redirect_local_path := maybe_redirect_local_path(request, hashtag):
+            return redirect_local_path
+
+        activities = (
+            models.Status.privacy_filter(
+                request.user,
+            )
+            .filter(
+                Q(mention_hashtags=hashtag),
+            )
+            .exclude(
+                privacy__in=["direct", "unlisted"],
+            )
+            .select_related(
+                "user",
+                "reply_parent",
+                "review__book",
+                "comment__book",
+                "quotation__book",
+            )
+            .prefetch_related(
+                "mention_books",
+                "mention_users",
+                "attachments",
+            )
+        )
+        paginated = Paginator(activities, PAGE_LENGTH)
+
+        data = {
+            "hashtag": hashtag.name,
+            "activities": paginated.get_page(request.GET.get("page", 1)),
+        }
+        return TemplateResponse(request, "hashtag.html", data)

bookwyrm/views/status.py

@@ -115,6 +115,19 @@ class CreateStatus(View):
         if status.reply_parent:
             status.mention_users.add(status.reply_parent.user)
 
+        # inspect the text for hashtags
+        for (mention_text, mention_hashtag) in find_or_create_hashtags(content).items():
+            # add them to status mentions fk
+            status.mention_hashtags.add(mention_hashtag)
+
+            # turn the mention into a link
+            content = re.sub(
+                rf"{mention_text}\b(?!@)",
+                rf'<a href="{mention_hashtag.remote_id}" data-mention="hashtag">'
+                + rf"{mention_text}</a>",
+                content,
+            )
+
         # deduplicate mentions
         status.mention_users.set(set(status.mention_users.all()))
 
@@ -237,6 +250,38 @@ def find_mentions(user, content):
     return username_dict
 
 
+def find_or_create_hashtags(content):
+    """detect #hashtags in raw status content
+
+    it stores hashtags case-sensitive, but ensures that an existing
+    hashtag with different case are found and re-used. for example,
+    an existing #BookWyrm hashtag will be found and used even if the
+    status content is using #bookwyrm.
+    """
+    if not content:
+        return {}
+
+    found_hashtags = {t.lower(): t for t in re.findall(regex.HASHTAG, content)}
+    if len(found_hashtags) == 0:
+        return {}
+
+    known_hashtags = {
+        t.name.lower(): t
+        for t in models.Hashtag.objects.filter(
+            Q(name__in=found_hashtags.keys())
+        ).distinct()
+    }
+
+    not_found = found_hashtags.keys() - known_hashtags.keys()
+    for lower_name in not_found:
+        tag_name = found_hashtags[lower_name]
+        mention_hashtag = models.Hashtag(name=tag_name)
+        mention_hashtag.save()
+        known_hashtags[lower_name] = mention_hashtag
+
+    return {found_hashtags[k]: v for k, v in known_hashtags.items()}
+
+
 def format_links(content):
     """detect and format links"""
     validator = URLValidator()