fix atom and rss feeds for users and tags

Changes:
  - make the XML closer to spec (RSS does not pass w3c's validator, but works)
  - fix dates (RFC3339 for Atom, doc says RFC822 for RSS but RFC1123 is closer)
  - fix attachment/enclosure links (but see below)
  - set feed item title to post's "summary" if present
  - pruned several elements that validators did not like
    - examples: ap_enabled, user banner urls.

Specs:
  - https://www.rssboard.org/rss-specification
  - https://validator.w3.org/feed/docs/atom.html
  - https://www.intertwingly.net/wiki/pie/Rss20AndAtom10Compared

Validators:
  - https://validator.w3.org/feed/
  - https://rssatom.com/feedvalidator.php

Attachment/enclosure links should have a "length" field (mandatory
according to the spec).  This is not present in the object's data
map.

lib/pleroma/web/feed/feed_view.ex

@@ -21,7 +21,7 @@ defmodule Pleroma.Web.Feed.FeedView do
     |> pub_date
   end
 
-  def pub_date(%DateTime{} = date), do: Timex.format!(date, "{RFC822}")
+  def pub_date(%DateTime{} = date), do: to_rfc1123(date)
 
   def prepare_activity(activity, opts \\ []) do
     object = Object.normalize(activity, fetch: false)
@@ -41,13 +41,18 @@ defmodule Pleroma.Web.Feed.FeedView do
 
   def most_recent_update(activities) do
     with %{updated_at: updated_at} <- List.first(activities) do
-      NaiveDateTime.to_iso8601(updated_at)
+      to_rfc3339(updated_at)
     end
   end
 
-  def most_recent_update(activities, user) do
+  def most_recent_update(activities, user, :atom) do
     (List.first(activities) || user).updated_at
-    |> NaiveDateTime.to_iso8601()
+    |> to_rfc3339()
+  end
+
+  def most_recent_update(activities, user, :rss) do
+    (List.first(activities) || user).updated_at
+    |> to_rfc1123()
   end
 
   def feed_logo do
@@ -61,6 +66,10 @@ defmodule Pleroma.Web.Feed.FeedView do
     |> MediaProxy.url()
   end
 
+  def email(user) do
+    user.nickname <> "@" <> Pleroma.Web.Endpoint.host()
+  end
+
   def logo(user) do
     user
     |> User.avatar_url()
@@ -69,18 +78,35 @@ defmodule Pleroma.Web.Feed.FeedView do
 
   def last_activity(activities), do: List.last(activities)
 
-  def activity_title(%{"content" => content}, opts \\ %{}) do
+  def activity_title(%{"content" => content, "summary" => summary} = data, opts \\ %{}) do
-    content
+    title =
+      cond do
+        summary != "" -> summary
+        content != "" -> activity_content(data)
+        true -> "a post"
+      end
+
+    title
     |> Pleroma.Web.Metadata.Utils.scrub_html()
     |> Pleroma.Emoji.Formatter.demojify()
     |> Formatter.truncate(opts[:max_length], opts[:omission])
     |> escape()
   end
 
+  def activity_description(data) do
+    content = activity_content(data)
+    summary = data["summary"]
+
+    cond do
+      content != "" -> escape(content)
+      summary != "" -> escape(summary)
+      true -> escape(data["type"])
+    end
+  end
+
   def activity_content(%{"content" => content}) do
     content
     |> String.replace(~r/[\n\r]/, "")
-    |> escape()
   end
 
   def activity_content(_), do: ""
@@ -112,4 +138,35 @@ defmodule Pleroma.Web.Feed.FeedView do
     |> html_escape()
     |> safe_to_string()
   end
+
+  @spec to_rfc3339(String.t() | NativeDateTime.t()) :: String.t()
+  def to_rfc3339(date) when is_binary(date) do
+    date
+    |> Timex.parse!("{ISO:Extended}")
+    |> to_rfc3339()
+  end
+
+  def to_rfc3339(nd) do
+    nd
+    |> Timex.to_datetime()
+    |> Timex.format!("{RFC3339}")
+  end
+
+  @spec to_rfc1123(String.t() | DateTime.t() | NativeDateTime.t()) :: String.t()
+  def to_rfc1123(datestr) when is_binary(datestr) do
+    datestr
+    |> Timex.parse!("{ISO:Extended}")
+    |> to_rfc1123()
+  end
+
+  def to_rfc1123(%DateTime{} = date) do
+    date
+    |> Timex.format!("{RFC1123}")
+  end
+
+  def to_rfc1123(nd) do
+    nd
+    |> Timex.to_datetime()
+    |> Timex.format!("{RFC1123}")
+  end
 end

lib/pleroma/web/templates/feed/feed/_activity.atom.eex

@@ -3,15 +3,15 @@
   <activity:verb>http://activitystrea.ms/schema/1.0/post</activity:verb>
   <id><%= @data["id"] %></id>
   <title><%= activity_title(@data, Keyword.get(@feed_config, :post_title, %{})) %></title>
-  <content type="html"><%= activity_content(@data) %></content>
+  <content type="html"><%= activity_description(@data) %></content>
-  <published><%= @activity.data["published"] %></published>
+  <published><%= to_rfc3339(@activity.data["published"]) %></published>
-  <updated><%= @activity.data["published"] %></updated>
+  <updated><%= to_rfc3339(@activity.data["published"]) %></updated>
   <ostatus:conversation ref="<%= activity_context(@activity) %>">
     <%= activity_context(@activity) %>
   </ostatus:conversation>
   <link href="<%= activity_context(@activity) %>" rel="ostatus:conversation"/>
 
-  <%= if @data["summary"] do %>
+  <%= if @data["summary"] != "" do %>
     <summary><%= escape(@data["summary"]) %></summary>
   <% end %>
 

lib/pleroma/web/templates/feed/feed/_activity.rss.eex

@@ -3,17 +3,12 @@
   <activity:verb>http://activitystrea.ms/schema/1.0/post</activity:verb>
   <guid><%= @data["id"] %></guid>
   <title><%= activity_title(@data, Keyword.get(@feed_config, :post_title, %{})) %></title>
-  <description><%= activity_content(@data) %></description>
+  <description><%= activity_description(@data) %></description>
-  <pubDate><%= @activity.data["published"] %></pubDate>
+  <pubDate><%= to_rfc1123(@activity.data["published"]) %></pubDate>
-  <updated><%= @activity.data["published"] %></updated>
   <ostatus:conversation ref="<%= activity_context(@activity) %>">
     <%= activity_context(@activity) %>
   </ostatus:conversation>
 
-  <%= if @data["summary"] do %>
-    <description><%= escape(@data["summary"]) %></description>
-  <% end %>
-
   <%= if @activity.local do %>
     <link><%= @data["id"] %></link>
   <% else %>
@@ -27,7 +22,7 @@
   <% end %>
 
   <%= for attachment <- @data["attachment"] || [] do %>
-    <link type="<%= attachment_type(attachment) %>"><%= attachment_href(attachment) %></link>
+    <enclosure url="<%= attachment_href(attachment) %>" type="<%= attachment_type(attachment) %>" />
   <% end %>
 
   <%= if @data["inReplyTo"] do %>

lib/pleroma/web/templates/feed/feed/_author.atom.eex

@@ -1,17 +1,14 @@
 <author>
-  <id><%= @user.ap_id %></id>
-  <activity:object>http://activitystrea.ms/schema/1.0/person</activity:object>
   <uri><%= @user.ap_id %></uri>
+  <name><%= @user.nickname %></name>
+  <activity:object>http://activitystrea.ms/schema/1.0/person</activity:object>
+  <activity:displayName><%= @user.name %></activity:displayName>
+  <activity:image><%= User.avatar_url(@user) %></activity:image>
+  <activity:id><%= @user.ap_id %></activity:id>
+  <activity:published><%= to_rfc3339(@user.inserted_at) %></activity:published>
+  <activity:updated><%= to_rfc3339(@user.updated_at) %></activity:updated>
+  <activity:url><%= @user.ap_id %></activity:url>
   <poco:preferredUsername><%= @user.nickname %></poco:preferredUsername>
   <poco:displayName><%= @user.name %></poco:displayName>
   <poco:note><%= escape(@user.bio) %></poco:note>
-  <summary><%= escape(@user.bio) %></summary>
-  <name><%= @user.nickname %></name>
-  <link rel="avatar" href="<%= User.avatar_url(@user) %>"/>
-  <%= if User.banner_url(@user) do %>
-    <link rel="header" href="<%= User.banner_url(@user) %>"/>
-  <% end %>
-  <%= if @user.local do %>
-    <ap_enabled>true</ap_enabled>
-  <% end %>
 </author>

lib/pleroma/web/templates/feed/feed/_author.rss.eex

@@ -1,17 +1,10 @@
-<managingEditor>
+<managingEditor><%= "#{email(@user)} (#{escape(@user.name)})" %></managingEditor>
-  <guid><%= @user.ap_id %></guid>
 <activity:object>http://activitystrea.ms/schema/1.0/person</activity:object>
-  <uri><%= @user.ap_id %></uri>
+<activity:displayName><%= @user.name %></activity:displayName>
+<activity:image><%= User.avatar_url(@user) %></activity:image>
+<activity:id><%= @user.ap_id %></activity:id>
+<activity:published><%= to_rfc3339(@user.inserted_at) %></activity:published>
+<activity:updated><%= to_rfc3339(@user.updated_at) %></activity:updated>
 <poco:preferredUsername><%= @user.nickname %></poco:preferredUsername>
 <poco:displayName><%= @user.name %></poco:displayName>
 <poco:note><%= escape(@user.bio) %></poco:note>
-  <description><%= escape(@user.bio) %></description>
-  <name><%= @user.nickname %></name>
-  <link rel="avatar"><%= User.avatar_url(@user) %></link>
-  <%= if User.banner_url(@user) do %>
-    <link rel="header"><%= User.banner_url(@user) %></link>
-  <% end %>
-  <%= if @user.local do %>
-    <ap_enabled>true</ap_enabled>
-  <% end %>
-</managingEditor>

lib/pleroma/web/templates/feed/feed/_tag_activity.atom.eex

@@ -6,7 +6,17 @@
 
   <id><%= @data["id"] %></id>
   <title><%= activity_title(@data, Keyword.get(@feed_config, :post_title, %{})) %></title>
-    <content type="html"><%= activity_content(@data) %></content>
+  <content type="html"><%= activity_description(@data) %></content>
+  <published><%= to_rfc3339(@activity.data["published"]) %></published>
+  <updated><%= to_rfc3339(@activity.data["published"]) %></updated>
+  <ostatus:conversation ref="<%= activity_context(@activity) %>">
+    <%= activity_context(@activity) %>
+  </ostatus:conversation>
+  <link href="<%= activity_context(@activity) %>" rel="ostatus:conversation"/>
+
+  <%= if @data["summary"] != "" do %>
+    <summary><%= @data["summary"] %></summary>
+  <% end %>
 
   <%= if @activity.local do %>
     <link type="application/atom+xml" href='<%= @data["id"] %>' rel="self"/>
@@ -15,18 +25,6 @@
     <link type="text/html" href='<%= @data["external_url"] %>' rel="alternate"/>
   <% end %>
 
-    <published><%= @activity.data["published"] %></published>
-    <updated><%= @activity.data["published"] %></updated>
-
-    <ostatus:conversation ref="<%= activity_context(@activity) %>">
-      <%= activity_context(@activity) %>
-    </ostatus:conversation>
-    <link href="<%= activity_context(@activity) %>" rel="ostatus:conversation"/>
-
-   <%= if @data["summary"] do %>
-    <summary><%= @data["summary"] %></summary>
-   <% end %>
-
   <%= for id <- @activity.recipients do %>
     <%= if id == Pleroma.Constants.as_public() do %>
       <link rel="mentioned"

lib/pleroma/web/templates/feed/feed/_tag_author.atom.eex

@@ -1,17 +1,13 @@
 <author>
-    <activity:object-type>http://activitystrea.ms/schema/1.0/person</activity:object-type>
-    <id><%= @actor.ap_id %></id>
   <uri><%= @actor.ap_id %></uri>
   <name><%= @actor.nickname %></name>
-    <summary><%= escape(@actor.bio) %></summary>
+  <activity:object-type>http://activitystrea.ms/schema/1.0/person</activity:object-type>
-    <link rel="avatar" href="<%= User.avatar_url(@actor) %>"/>
+  <activity:displayName><%= @actor.name %></activity:displayName>
-    <%= if User.banner_url(@actor) do %>
+  <activity:image><%= User.avatar_url(@actor) %></activity:image>
-      <link rel="header" href="<%= User.banner_url(@actor) %>"/>
+  <activity:id><%= @actor.ap_id %></activity:id>
-    <% end %>
+  <activity:published><%= to_rfc3339(@actor.inserted_at) %></activity:published>
-    <%= if @actor.local do %>
+  <activity:updated><%= to_rfc3339(@actor.updated_at) %></activity:updated>
-      <ap_enabled>true</ap_enabled>
+  <activity:url><%= @actor.ap_id %></activity:url>
-    <% end %>
-  
   <poco:preferredUsername><%= @actor.nickname %></poco:preferredUsername>
   <poco:displayName><%= @actor.name %></poco:displayName>
   <poco:note><%= escape(@actor.bio) %></poco:note>

lib/pleroma/web/templates/feed/feed/tag.atom.eex

@@ -1,21 +1,19 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<feed xml:lang="<%= Gettext.language_tag() %>" xmlns="http://www.w3.org/2005/Atom"
+<feed
-      xmlns:thr="http://purl.org/syndication/thread/1.0"
+  xmlns="http://www.w3.org/2005/Atom"
-      xmlns:georss="http://www.georss.org/georss"
   xmlns:activity="http://activitystrea.ms/spec/1.0/"
-      xmlns:media="http://purl.org/syndication/atommedia"
   xmlns:poco="http://portablecontacts.net/spec/1.0"
   xmlns:ostatus="http://ostatus.org/schema/1.0"
   xmlns:statusnet="http://status.net/schema/api/1/">
 
-    <id><%= '#{Routes.tag_feed_url(@conn, :feed, @tag)}.rss' %></id>
+  <id><%= Routes.tag_feed_url(@conn, :feed, @tag) <> ".atom" %></id>
   <title>#<%= @tag %></title>
-
   <subtitle><%= Gettext.dpgettext("static_pages", "tag feed description", "These are public toots tagged with #%{tag}. You can interact with them if you have an account anywhere in the fediverse.", tag: @tag) %></subtitle>
   <logo><%= feed_logo() %></logo>
   <updated><%= most_recent_update(@activities) %></updated>
   <link rel="self" href="<%= '#{Routes.tag_feed_url(@conn, :feed, @tag)}.atom'  %>" type="application/atom+xml"/>
+
   <%= for activity <- @activities do %>
   <%= render Phoenix.Controller.view_module(@conn), "_tag_activity.atom", Map.merge(assigns, prepare_activity(activity, actor: true)) %>
   <% end %>

lib/pleroma/web/templates/feed/feed/user.atom.eex

@@ -1,14 +1,14 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <feed
   xmlns="http://www.w3.org/2005/Atom"
-  xmlns:thr="http://purl.org/syndication/thread/1.0"
   xmlns:activity="http://activitystrea.ms/spec/1.0/"
   xmlns:poco="http://portablecontacts.net/spec/1.0"
   xmlns:ostatus="http://ostatus.org/schema/1.0">
 
   <id><%= Routes.user_feed_url(@conn, :feed, @user.nickname) <> ".atom" %></id>
   <title><%= @user.nickname <> "'s timeline" %></title>
-  <updated><%= most_recent_update(@activities, @user) %></updated>
+  <subtitle><%= escape(@user.bio) %></subtitle>
+  <updated><%= most_recent_update(@activities, @user, :atom) %></updated>
   <logo><%= logo(@user) %></logo>
   <link rel="self" href="<%= '#{Routes.user_feed_url(@conn, :feed, @user.nickname)}.atom' %>" type="application/atom+xml"/>
 

lib/pleroma/web/templates/feed/feed/user.rss.eex

@@ -1,11 +1,20 @@
 <?xml version="1.0" encoding="UTF-8" ?>
-<rss version="2.0">
+<rss version="2.0"
+     xmlns:atom="http://www.w3.org/2005/Atom"
+     xmlns:activity="http://activitystrea.ms/spec/1.0/"
+     xmlns:ostatus="http://ostatus.org/schema/1.0"
+     xmlns:poco="http://portablecontacts.net/spec/1.0">
   <channel>
-    <guid><%= Routes.user_feed_url(@conn, :feed, @user.nickname) <> ".rss" %></guid>
     <title><%= @user.nickname <> "'s timeline" %></title>
-    <updated><%= most_recent_update(@activities, @user) %></updated>
-    <image><%= logo(@user) %></image>
     <link><%= '#{Routes.user_feed_url(@conn, :feed, @user.nickname)}.rss' %></link>
+    <atom:link href="<%= Routes.user_feed_url(@conn, :feed, @user.nickname) <> ".atom" %>"
+               rel="self" type="application/rss+xml" />
+    <description><%= escape(@user.bio) %></description>
+    <image>
+      <url><%= logo(@user) %></url>
+      <title><%= @user.nickname <> "'s timeline" %></title>
+      <link><%= '#{Routes.user_feed_url(@conn, :feed, @user.nickname)}.rss' %></link>
+    </image>
 
     <%= render Phoenix.Controller.view_module(@conn), "_author.rss", assigns %>