Make hashtags in video titles clickable

src/invidious/helpers/utils.cr

@@ -386,6 +386,18 @@ def parse_link_endpoint(endpoint : JSON::Any, text : String, video_id : String)
   return text
 end
 
+def linkify_hashtags(title : String) : String
+  String.build do |str|
+    pos = 0
+    title.scan(/#([a-zA-Z0-9_]+)/) do |match|
+      str << title[pos...match.begin(0)]
+      str << %(<a href="/hashtag/#{URI.encode_path(match[1])}">#{match[0]}</a>)
+      pos = match.end(0)
+    end
+    str << title[pos..]
+  end
+end
+
 def encrypt_ecb_without_salt(data, key)
   cipher = OpenSSL::Cipher.new("aes-128-ecb")
   cipher.encrypt

src/invidious/views/watch.ecr

@@ -93,7 +93,11 @@ we're going to need to do it here in order to allow for translations.
 
 <div class="h-box">
     <h1>
-        <%= title %>
+        <% if video.title.matches?(/#\w/) %>
+            <%= linkify_hashtags(title) %>
+        <% else %>
+            <%= title %>
+        <% end %>
         <% if params.listen %>
             <a title="<%=I18n.translate(locale, "Video mode")%>" id="link-iv-listen" data-base-url="/watch?<%= env.params.query %>&listen=0" href="/watch?<%= env.params.query %>&listen=0">
                 <i class="icon ion-ios-videocam"></i>