rss feeds on communities

app/activitypub/routes.py

@@ -199,7 +199,7 @@ def community_profile(actor):
     if '@' in actor:
         # don't provide activitypub info for remote communities
         if 'application/ld+json' in request.headers.get('Accept', '') or 'application/activity+json' in request.headers.get('Accept', ''):
-            abort(404)
+            abort(400)
         community: Community = Community.query.filter_by(ap_id=actor, banned=False).first()
     else:
         community: Community = Community.query.filter_by(name=actor, banned=False, ap_id=None).first()

app/community/routes.py

@@ -19,8 +19,8 @@ from app.utils import get_setting, render_template, allowlist_html, markdown_to_
     shorten_string, markdown_to_text, domain_from_url, validate_image, gibberish, community_membership, ap_datetime, \
     request_etag_matches, return_304
 import os
-from PIL import Image, ImageOps
+from feedgen.feed import FeedGenerator
-from datetime import datetime
+from datetime import timezone
 
 
 @bp.route('/add_local', methods=['GET', 'POST'])
@@ -117,7 +117,59 @@ def show_community(community: Community):
     return render_template('community/community.html', community=community, title=community.title,
                            is_moderator=is_moderator, is_owner=is_owner, mods=mod_list, posts=posts, description=description,
                            og_image=og_image, POST_TYPE_IMAGE=POST_TYPE_IMAGE, POST_TYPE_LINK=POST_TYPE_LINK, SUBSCRIPTION_PENDING=SUBSCRIPTION_PENDING,
-                           SUBSCRIPTION_MEMBER=SUBSCRIPTION_MEMBER, etag=f"{community.id}_{hash(community.last_active)}")
+                           SUBSCRIPTION_MEMBER=SUBSCRIPTION_MEMBER, etag=f"{community.id}_{hash(community.last_active)}",
+                           rss_feed=f"https://{current_app.config['SERVER_NAME']}/community/{community.link()}/feed", rss_feed_name=f"{community.title} posts on PieFed")
+
+
+# RSS feed of the community
+@bp.route('/<actor>/feed', methods=['GET'])
+@cache.cached(timeout=600)
+def show_community_rss(actor):
+    actor = actor.strip()
+    if '@' in actor:
+        community: Community = Community.query.filter_by(ap_id=actor, banned=False).first()
+    else:
+        community: Community = Community.query.filter_by(name=actor, banned=False, ap_id=None).first()
+    if community is not None:
+        # If nothing has changed since their last visit, return HTTP 304
+        current_etag = f"{community.id}_{hash(community.last_active)}"
+        if request_etag_matches(current_etag):
+            return return_304(current_etag, 'application/rss+xml')
+
+        posts = community.posts.filter(Post.from_bot == False).order_by(desc(Post.created_at)).limit(100).all()
+        description = shorten_string(community.description, 150) if community.description else None
+        og_image = community.image.source_url if community.image_id else None
+        fg = FeedGenerator()
+        fg.id(f"https://{current_app.config['SERVER_NAME']}/c/{actor}")
+        fg.title(community.title)
+        fg.link(href=f"https://{current_app.config['SERVER_NAME']}/c/{actor}", rel='alternate')
+        if og_image:
+            fg.logo(og_image)
+        else:
+            fg.logo(f"https://{current_app.config['SERVER_NAME']}/static/images/apple-touch-icon.png")
+        if description:
+            fg.subtitle(description)
+        else:
+            fg.subtitle(' ')
+        fg.link(href=f"https://{current_app.config['SERVER_NAME']}/c/{actor}/feed", rel='self')
+        fg.language('en')
+
+        for post in posts:
+            fe = fg.add_entry()
+            fe.title(post.title)
+            fe.link(href=f"https://{current_app.config['SERVER_NAME']}/post/{post.id}")
+            fe.description(post.body_html)
+            fe.guid(post.profile_id(), permalink=True)
+            fe.author(name=post.author.user_name)
+            fe.pubDate(post.created_at.replace(tzinfo=timezone.utc))
+
+        response = make_response(fg.rss_str())
+        response.headers.set('Content-Type', 'application/rss+xml')
+        response.headers.add_header('ETag', f"{community.id}_{hash(community.last_active)}")
+        response.headers.add_header('Cache-Control', 'no-cache, max-age=600, must-revalidate')
+        return response
+    else:
+        abort(404)
 
 
 @bp.route('/<actor>/subscribe', methods=['GET'])

app/static/scss/_typography.scss

@@ -186,6 +186,10 @@
   content: "\e91e";
 }
 
+.fe-rss::before {
+  content: "\e9be";
+}
+
 .fe-image {
   position: relative;
   top: 2px;

app/static/structure.css

@@ -189,6 +189,10 @@ nav, etc which are used site-wide */
   content: "\e91e";
 }
 
+.fe-rss::before {
+  content: "\e9be";
+}
+
 .fe-image {
   position: relative;
   top: 2px;

app/static/styles.css

@@ -188,6 +188,10 @@
   content: "\e91e";
 }
 
+.fe-rss::before {
+  content: "\e9be";
+}
+
 .fe-image {
   position: relative;
   top: 2px;

app/templates/base.html

@@ -48,6 +48,9 @@
         {% if og_image %}
             <meta property="og:image" content="{{ og_image }}" />
         {% endif %}
+        {% if rss_feed %}
+            <link rel="alternate" type="application/rss+xml" title="{{ rss_feed_name }}" href="{{ rss_feed }}" />
+        {% endif %}
     {% endblock %}
   </head>
   <body class="d-flex flex-column" style="padding-top: 78px;">

app/templates/community/community.html

@@ -81,6 +81,9 @@
                         {% endfor %}
                     </ol>
                 {% endif %}
+                <p class="mt-4">
+                    <a class="no-underline" href="{{ rss_feed }}" rel="nofollow"><span class="fe fe-rss"></span> RSS feed</a>
+                </p>
             </div>
         </div>
         {% if is_moderator %}

app/utils.py

@@ -37,16 +37,19 @@ def render_template(template_name: str, **context) -> Response:
 
 
 def request_etag_matches(etag):
+    print(str(request.headers))
     if 'If-None-Match' in request.headers:
         old_etag = request.headers['If-None-Match']
         return old_etag == etag
     return False
 
 
-def return_304(etag):
+def return_304(etag, content_type=None):
     resp = make_response('', 304)
     resp.headers.add_header('ETag', request.headers['If-None-Match'])
     resp.headers.add_header('Cache-Control', 'no-cache, max-age=600, must-revalidate')
+    if content_type:
+        resp.headers.set('Content-Type', content_type)
     return resp
 
 

requirements.txt

@@ -25,3 +25,4 @@ flask-caching==2.0.2
 Pillow
 pillow-heif
 opengraph-parse=0.0.6
+feedgen==0.9.0