views: update seo title and description of post index page.

Change the title of the post index page to look like this:

    "Danbooru: Anime Image Board" (for the front page)
    "Kantai Collection Art | Danbooru" (for a tag search)

Change the meta description of the front page to look like this:

    Danbooru is the original anime image 'booru. Find over 3.75 million
    anime pictures categorized by over 100 million tags.

Change the meta description for a tag search to look like this:

    Find over 37,168 Azur Lane images on Danbooru. Azur Lane (碧蓝航线)
    (벽람항로) is a Chinese shipgirl-themed side-scrolling shoot 'em up
    mobile game developed by Shanghai Manjuu and Xiamen Yongshi...

app/helpers/application_helper.rb

@@ -269,26 +269,34 @@ module ApplicationHelper
     end.to_h
   end
 
-  def page_title(title = nil)
+  def page_title(title = nil, suffix: "| #{Danbooru.config.app_name}")
     if title.present?
-      content_for(:page_title) { "#{title} | #{Danbooru.config.app_name}" }
+      content_for(:page_title) { "#{title} #{suffix}".strip }
     elsif content_for(:page_title).present?
       content_for(:page_title)
     elsif params[:action] == "index"
-      "#{params[:controller].titleize} | #{Danbooru.config.app_name}"
+      "#{params[:controller].titleize} #{suffix}"
     elsif params[:action] == "show"
-      "#{params[:controller].singularize.titleize} | #{Danbooru.config.app_name}"
+      "#{params[:controller].singularize.titleize} #{suffix}"
     elsif params[:action] == "new"
-      "New #{params[:controller].singularize.titleize} | #{Danbooru.config.app_name}"
+      "New #{params[:controller].singularize.titleize} #{suffix}"
     elsif params[:action] == "edit"
-      "Edit #{params[:controller].singularize.titleize} | #{Danbooru.config.app_name}"
+      "Edit #{params[:controller].singularize.titleize} #{suffix}"
     elsif params[:action] == "search"
-      "Search #{params[:controller].titleize} | #{Danbooru.config.app_name}"
+      "Search #{params[:controller].titleize} #{suffix}"
     else
       "#{Danbooru.config.app_name}/#{params[:controller]}"
     end
   end
 
+  def meta_description(description = nil)
+    if description.present?
+      content_for(:meta_description) { description }
+    elsif content_for(:meta_description).present?
+      content_for(:meta_description)
+    end
+  end
+
   def show_moderation_notice?
     CurrentUser.can_approve_posts? && (cookies[:moderated].blank? || Time.at(cookies[:moderated].to_i) < 72.hours.ago)
   end

app/helpers/wiki_pages_helper.rb

@@ -1,7 +1,7 @@
 module WikiPagesHelper
   def wiki_page_excerpt(wiki_page)
     text = strip_dtext(wiki_page.body).split(/\r\n|\r|\n/).first
-    truncate(text, length: 160)
+    text.truncate(160)
   end
 
   def wiki_page_other_names_list(wiki_page)

app/logical/post_sets/post.rb

@@ -17,7 +17,7 @@ module PostSets
     end
 
     def humanized_tag_string
-      tag_array.slice(0, 25).join(" ").tr("_", " ")
+      tag_array.map { |tag| tag.tr("_", " ").titleize }.to_sentence
     end
 
     def has_blank_wiki?

app/presenters/post_presenter.rb

@@ -160,10 +160,6 @@ class PostPresenter < Presenter
     PostPresenter.preview(@post)
   end
 
-  def humanized_tag_string
-    @post.tag_string.split(/ /).slice(0, 25).join(", ").tr("_", " ")
-  end
-
   def humanized_essential_tag_string
     @humanized_essential_tag_string ||= tag_set_presenter.humanized_essential_tag_string(default: "##{@post.id}")
   end

app/views/layouts/default.html.erb

@@ -48,7 +48,7 @@
     "@context": "http://schema.org",
     "@type": "WebSite",
     "name": "<%= Danbooru.config.app_name %>",
-    "alternateName": "<%= Danbooru.config.description %>",
+    "alternateName": "Anime Image Board",
     "url" : "<%= root_url %>"
   }
   </script>
@@ -76,6 +76,11 @@
   </script>
   <%= tag.meta name: "twitter:title", content: page_title %>
   <%= tag.meta name: "og:title", content: page_title %>
+  <% if meta_description.present? %>
+    <%= tag.meta name: "description", content: meta_description %>
+    <%= tag.meta name: "og:description", content: meta_description %>
+    <%= tag.meta name: "twitter:description", content: meta_description %>
+  <% end %>
   <%= yield :html_header %>
   <%= raw Danbooru.config.custom_html_header_content %>
 </head>

app/views/posts/index.html.erb

@@ -58,20 +58,6 @@
   <%= render "posts/partials/common/secondary_links" %>
 <% end %>
 
-<% content_for(:page_title) do %>
-  <% if @post_set.tag_string.present? %>
-    <%= @post_set.humanized_tag_string %> - <%= Danbooru.config.app_name %>
-  <% else %>
-    <%= Danbooru.config.app_name %>
-  <% end %>
-<% end %>
-
 <% content_for(:html_header) do %>
-  <%= tag.link href: posts_path(format: "atom", tags: params[:tags]), rel: "alternate", title: "ATOM", type: "application/atom+xml" %>
-  <%= tag.link rel: "next", href: next_page_url %>
-  <% if prev_page_url %>
-    <%= tag.link rel: "prev", href: prev_page_url %>
-  <% end %>
-  <%= missed_post_search_count_js %>
   <%= render "posts/partials/index/seo_meta_tags" %>
 <% end %>

app/views/posts/partials/index/_seo_meta_tags.html.erb

@@ -1,3 +1,18 @@
+<% if @post_set.is_empty_tag? %>
+  <% page_title("#{Danbooru.config.app_name}: Anime Image Board", suffix: nil) %>
+  <% meta_description("#{Danbooru.config.canonical_app_name} is the original anime image 'booru. Find over 3.75 million anime pictures categorized by over 100 million tags.") %>
+<% else %>
+  <% page_title("#{@post_set.humanized_tag_string} Art") %>
+  <% meta_description("Find over #{number_with_delimiter(@post_set.post_count)} #{@post_set.humanized_tag_string} images on #{Danbooru.config.app_name}. #{wiki_page_excerpt(@post_set.wiki_page) if @post_set.wiki_page}") %>
+<% end %>
+
+<%= tag.link href: posts_path(format: "atom", tags: params[:tags]), rel: "alternate", title: "ATOM", type: "application/atom+xml" %>
+<%= tag.link rel: "next", href: next_page_url %>
+<% if prev_page_url %>
+  <%= tag.link rel: "prev", href: prev_page_url %>
+<% end %>
+<%= missed_post_search_count_js %>
+
 <% if @post_set.hide_from_crawler? %>
   <meta name="robots" content="nofollow,noindex">
 <% end %>
@@ -8,20 +23,6 @@
 
 <%= tag.meta name: "canonical", content: posts_url(tags: params[:tags], host: Danbooru.config.hostname, protocol: "https") %>
 
-<% if @post_set.is_single_tag? %>
-  <% "Find #{@post_set.post_count} images of #{@post_set.humanized_tag_string.titleize} on #{Danbooru.config.app_name}".tap do |desc| %>
-    <%= tag.meta name: "description", content: desc %>
-    <%= tag.meta name: "og:description", content: desc %>
-    <%= tag.meta name: "twitter:description", content: desc %>
-  <% end %>
-<% else %>
-  <% Danbooru.config.description.tap do |desc| %>
-    <%= tag.meta name: "description", content: desc %>
-    <%= tag.meta name: "og:description", content: desc %>
-    <%= tag.meta name: "twitter:description", content: desc %>
-  <% end %>
-<% end %>
-
 <%= tag.meta name: "og:type", content: "website" %>
 <%= tag.meta name: "og:site", content: Danbooru.config.app_name %>
 

app/views/posts/partials/index/_share.html.erb

@@ -1,5 +1,5 @@
 <div class="addthis_toolbox addthis_default_style addthis_32x32_style"
-     addthis:title="Find more art about <%= @post_set.humanized_tag_string %> on <%= Danbooru.config.app_name %>">
+     addthis:title="Find over <%= @post_set.post_count %> <%= @post_set.humanized_tag_string %> images on <%= Danbooru.config.app_name %>">
   <a class="addthis_button_twitter"></a>
   <a class="addthis_button_facebook"></a>
   <a class="addthis_button_reddit"></a>

config/danbooru_default_config.rb

@@ -25,10 +25,6 @@ module Danbooru
       "Danbooru"
     end
 
-    def description
-      "Find good anime art fast"
-    end
-
     # The canonical hostname of the site.
     def hostname
       Socket.gethostname