Document and reorganize code 4 chan's feat. chans

src/invidious/channel/featured_channels.cr

@@ -1,82 +1,58 @@
-def fetch_channel_featured_channels(ucid, params, view = nil, shelf_id = nil, continuation = nil, query_title = nil) : {Array(Category), (String | Nil)}
-  # Continuation to load more channel catagories
-  if continuation.is_a?(String)
-    initial_data = request_youtube_api_browse(continuation)
-    items = extract_items(initial_data)
-    continuation_token = fetch_continuation_token(initial_data)
+# Fetches the featured channel categories of a channel
+#
+# Returned as an array of Category objects containing different channels.
+def fetch_channel_featured_channels(ucid) : Array(Category)
+  initial_data = request_youtube_api_browse(ucid, "EghjaGFubmVscw%3D%3D")
 
-    return [Category.new({
-      title:            query_title.not_nil!, # If continuation contents is requested then the query_title has to be passed along.
+  channels_tab = extract_selected_tab(initial_data["contents"]["twoColumnBrowseResultsRenderer"]["tabs"])
+
+  # The submenu is the content type menu, and is used to select which categories to view fully.
+  # As a result, it contains the category title which we'll use as a fallback, since Innertube doesn't
+  # return the title when the channel only has one featured channel category.
+  submenu = channels_tab["content"]["sectionListRenderer"]["subMenu"]?
+
+  # If the featured channel tabs lacks categories then that means the channel doesn't feature any other channels.
+  if !submenu
+    return [] of Category
+  end
+
+  # Fetches the fallback title.
+  submenu_data = submenu["channelSubMenuRenderer"]["contentTypeSubMenuItems"]
+  fallback_title = submenu_data.as_a.select(&.["selected"].as_bool)[0]["title"].as_s
+
+  items = extract_items(initial_data)
+
+  category_array = [] of Category
+  items.each do |category|
+    # The items can either be an Array of Categories or an Array of channels.
+    if !category.is_a?(Category)
+      break
+    end
+
+    # category.title = category.title.empty? ? fallback_title : category.title
+    category_array << category
+  end
+
+  # If the returned data is only an array of channels then it means that the featured channel tab only has one category.
+  # This is due to the fact that InnerTube uses a "gridRenderer" (an array of items) when only one category is present.
+  # However, as the InnerTube result is a "gridRenderer" and not an "shelfRenderer", an object representing an
+  # category or section on youtube, we'll lack the category title. But, the good news is that the title of the category is still stored within the submenu
+  # which we fetched above. We can then use all of these values together to produce a Category object.
+  if category_array.empty?
+    category_array << Category.new({
+      title:            fallback_title,
       contents:         items,
       description_html: "",
       url:              nil,
       badges:           nil,
-    })], continuation_token
-  else
-    url = nil
-    if view && shelf_id
-      url = "/channel/#{ucid}/channels?view=#{view}&shelf_id=#{shelf_id}"
-
-      params = produce_featured_channel_browse_param(view.to_i64, shelf_id.to_i64)
-      initial_data = request_youtube_api_browse(ucid, params)
-      continuation_token = fetch_continuation_token(initial_data)
-    else
-      initial_data = request_youtube_api_browse(ucid, params)
-      continuation_token = nil
-    end
-
-    channels_tab = extract_selected_tab(initial_data["contents"]["twoColumnBrowseResultsRenderer"]["tabs"])
-    submenu = channels_tab["content"]["sectionListRenderer"]["subMenu"]?
-
-    # There's no submenu data if the channel doesn't feature any channels.
-    if !submenu
-      return {[] of Category, continuation_token}
-    end
-
-    submenu_data = submenu["channelSubMenuRenderer"]["contentTypeSubMenuItems"]
-
-    items = extract_items(initial_data)
-    fallback_title = submenu_data.as_a.select(&.["selected"].as_bool)[0]["title"].as_s
-
-    # Although extract_items parsed everything into the right structs, we still have
-    # to fill in the title (if missing) attribute since Youtube doesn't return it when requesting
-    # a full category (initial)
-    category_array = [] of Category
-    items.each do |category|
-      # Tell compiler that the result from extract_items has to be an array of Categories
-      if !category.is_a?(Category)
-        next
-      end
-
-      category_array << Category.new({
-        title:            category.title.empty? ? fallback_title : category.title,
-        contents:         category.contents,
-        description_html: category.description_html,
-        url:              category.url,
-        badges:           nil,
-      })
-    end
-
-    # If no categories has been parsed then it means two things.
-    #   - We're currently viewing a specific channel category
-    #   - We're currently requesting the continuation contents for that specific category.
-    # And since Youtube dyanmically loads more channels onto the page via JS, the data returned from InnerTube will only contains
-    # channels. Thus, we'll just go ahead and create one for the template to use.
-    if category_array.empty?
-      category_array << Category.new({
-        title:            fallback_title,
-        contents:         items,
-        description_html: "",
-        url:              url,
-        badges:           nil,
-      })
-    end
-
-    return category_array, continuation_token
+    })
   end
+
+  return category_array
 end
 
-def produce_featured_channel_browse_param(view : Int64, shelf_id : Int64)
+# Produces the InnerTube parameter for requesting the contents of a specific channel featuring category
+private def produce_featured_channel_browse_param(view : Int64, shelf_id : Int64)
   object = {
     "2:string"  => "channels",
     "4:varint"  => view,
@@ -90,3 +66,50 @@ def produce_featured_channel_browse_param(view : Int64, shelf_id : Int64)
 
   return browse_params
 end
+
+# Fetches the first set of channels from a selected channel featuring category
+def fetch_selected_channel_featuring_category(ucid, view, shelf_id) : Tuple(Category, String | Nil)
+  category_url = "/channel/#{ucid}/channels?view=#{view}&shelf_id=#{shelf_id}"
+
+  params = produce_featured_channel_browse_param(view.to_i64, shelf_id.to_i64)
+  initial_data = request_youtube_api_browse(ucid, params)
+  channels_tab = extract_selected_tab(initial_data["contents"]["twoColumnBrowseResultsRenderer"]["tabs"])
+  continuation_token = fetch_continuation_token(initial_data)
+
+  # Fetches the fallback title
+  submenu = channels_tab["content"]["sectionListRenderer"]["subMenu"]
+  submenu_data = submenu["channelSubMenuRenderer"]["contentTypeSubMenuItems"]
+  fallback_title = submenu_data.as_a.select(&.["selected"].as_bool)[0]["title"].as_s
+
+  items = extract_items(initial_data)
+
+  # Since the returned items from InnerTube is an array of channels, (See explanation at the end of the fetch_channel_featured_channels function)
+  # we lack the category title attribute. However, it is still stored as a submenu data which we fetched above. We can then use all of these
+  # values together to produce a Category object.
+  return Category.new({
+    title:            fallback_title,
+    contents:         items,
+    description_html: "",
+    url:              category_url,
+    badges:           nil,
+  }), continuation_token
+end
+
+# Fetches the next set of channels within the selected channel featuring category.
+# Requires the continuation token and the query_title.
+#
+# TODO: The query_title here is really only used for frontend rendering.
+#  And since it's a URL parameter we should be able to just request it directly within the template files.
+def fetch_channel_featured_channels_category_continuation(continuation, query_title) : Tuple(Category, String | Nil)
+  initial_data = request_youtube_api_browse(continuation)
+  items = extract_items(initial_data)
+  continuation_token = fetch_continuation_token(initial_data)
+
+  return Category.new({
+    title:            query_title.not_nil!, # If continuation contents is requested then the query_title has to be passed along.
+    contents:         items,
+    description_html: "",
+    url:              nil,
+    badges:           nil,
+  }), continuation_token
+end

src/invidious/routes/channels.cr

@@ -114,33 +114,35 @@ module Invidious::Routes::Channels
       return env.redirect "/channel/#{channel.ucid}"
     end
 
-    # When a channel only has a single category it lacks the category param option so we'll handle it here.
-    if continuation
-      offset = env.params.query["offset"]?
-      if offset
-        offset = offset.to_i
-      else
-        offset = 0
-      end
+    view = env.params.query["view"]?
+    shelf_id = env.params.query["shelf_id"]?
 
-      # Previous continuation
-      previous_continuation = env.params.query["previous"]?
-
-      featured_channel_categories, continuation_token = fetch_channel_featured_channels(ucid, "EghjaGFubmVscw%3D%3D", nil, nil, continuation, current_category_title).not_nil!
-    elsif view && shelf_id
-      offset = env.params.query["offset"]?
-      if offset
-        offset = offset.to_i
-      else
-        offset = 0
-      end
-
-      featured_channel_categories, continuation_token = fetch_channel_featured_channels(ucid, "EghjaGFubmVscw%3D%3D", view, shelf_id, continuation, current_category_title).not_nil!
+    # The offset is mainly to check if we're at the first page or not and in turn whether we should have a "previous page" button or not.
+    offset = env.params.query["offset"]?
+    if offset
+      offset = offset.to_i
     else
-      previous_continuation = nil
       offset = 0
+    end
 
-      featured_channel_categories, continuation_token = fetch_channel_featured_channels(ucid, "EghjaGFubmVscw%3D%3D", nil, nil, current_category_title).not_nil!
+    # Category title isn't returned when requesting a specific category or continuation data
+    # so we have it in through a url param
+    current_category_title = env.params.query["title"]?
+
+    previous_continuation = env.params.query["previous"]?
+
+    if continuation
+      featured_channel_categories, continuation_token = fetch_channel_featured_channels_category_continuation(continuation, current_category_title)
+    elsif view && shelf_id
+      featured_channel_categories, continuation_token = fetch_selected_channel_featuring_category(ucid, view, shelf_id)
+    else
+      continuation_token = nil
+      featured_channel_categories = fetch_channel_featured_channels(ucid)
+    end
+
+    # If we only got a single category we'll go ahead and wrap it within an array for easier processing in the template.
+    if featured_channel_categories.is_a? Category
+      featured_channel_categories = [featured_channel_categories]
     end
 
     templated "channel/featured_channels", buffer_footer: true

src/invidious/views/channel/featured_channels.ecr

@@ -91,6 +91,7 @@
 
 <% if !featured_channel_categories.empty? %>
     <% base_url = "/channel/#{channel.ucid}/channels?view=#{view}&shelf_id=#{shelf_id}" %>
+
     <div class="pure-g h-box">
         <div class="pure-u-1 pure-u-lg-1-5">
             <% if previous_continuation %>