Add canonical meta header

Author: jschwindt

app/helpers/application_helper.rb

@@ -16,6 +16,10 @@ def meta_description(text, og_type = 'website')
     @meta_og_type = og_type
   end
 
+  def canonical_url(url)
+    @canonical_url = url
+  end
+
   def alert_message_for(object)
     if object.respond_to?(:errors) && object.errors.any?
       messages = object.errors.full_messages.map { |msg| content_tag(:li, msg) }.join
@@ -69,6 +73,6 @@ def month_and_year_select(name, options = {}, html_options = {})
       p = {}
     end
   end
-  content_tag(:div, class: 'select') { select_month(p[:month].to_i, options, html_options) } + 
+  content_tag(:div, class: 'select') { select_month(p[:month].to_i, options, html_options) } +
     content_tag(:div, class: 'select') { select_year(p[:year].to_i, options, html_options) }
 end

app/views/comments/show.html.erb

@@ -1,6 +1,7 @@
 <% the_title = "Comentario ##{@comment.id} de #{@post.title}" -%>
 <% page_title the_title -%>
 <% meta_description the_title -%>
+<%- canonical_url(post_comment_url(@post, @comment)) %>
 <h2 class="title fancy is-4"><%= link_to @post.title, @post %></h2>
 <h2 class="title"><%= %"Comentario ##{@comment.id}" %></h2>
 <div class="post-show">

app/views/home/index.html.erb

@@ -1,4 +1,5 @@
 <%- page_title(nil) %>
+<%- canonical_url(root_url) %>
 <section>
   <h2 class="title fancy is-4">Programas Recientes</h2>
   <div class="posts">

app/views/layouts/application.html.erb

@@ -9,7 +9,7 @@
     <%= tag 'meta', name: 'twitter:card',       content: 'summary' %>
     <%= tag 'meta', name: 'twitter:site',       content: '@venganzaspasado' %>
     <%= tag 'meta', name: 'twitter:creator',    content: '@jschwindt' %>
-    <%= tag 'meta', property: 'og:url',         content: request.original_url %>
+    <%= tag 'meta', property: 'og:url',         content: @canonical_url || request.original_url %>
     <%= tag 'meta', property: 'og:title',       content: yield(:title) %>
     <%= tag 'meta', property: 'og:description', content: @meta_description || 'El sitio donde podés escuchar online y descargar los archivos de audio en MP3 del programa La Venganza será Terrible de Alejandro Dolina.' %>
     <%= tag 'meta', property: 'og:image',       content: asset_url('vdp_logo.jpg') %>
@@ -18,6 +18,7 @@
     <%= tag 'meta', property: 'fb:app_id',      content: '39744394508' %>
     <%= tag 'meta', property: 'fb:admins',      content: 'jschwindt' %>
     <%= favicon_link_tag '/favicon.ico' %>
+    <% if @canonical_url %><link rel="canonical" href="<%= @canonical_url %>" /><% end %>
     <link rel="preload" href="<%= asset_path('fas.woff2') %>" as="font" type="font/woff2" crossorigin>
     <link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Didact+Gothic&display=swap">
     <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png">

app/views/posts/archive.html.erb

@@ -1,9 +1,12 @@
 <% if params[:day].present? %>
   <% title_part = "Archivo de programas del #{params[:day]}/#{params[:month]}/#{params[:year]}" -%>
+  <%- canonical_url(posts_archive_url params[:year], params[:month], params[:day]) %>
 <% elsif params[:month].present? %>
   <% title_part = "Archivo de programas de #{I18n.t('date.month_names')[params[:month].to_i].capitalize} de #{params[:year]}" -%>
+  <%- canonical_url(posts_archive_url params[:year], params[:month]) %>
 <% else -%>
   <% title_part = "Archivo de programas del año #{params[:year]}" -%>
+  <%- canonical_url(posts_archive_url params[:year]) %>
 <% end %>
 <% if params[:page].nil? %>
   <% the_title = title_part %>

app/views/posts/contributions.html.erb

@@ -1,7 +1,9 @@
 <% if params[:page].nil? %>
   <% the_title = "Contribuciones de Programas de La Venganza será Terrible" -%>
+  <%- canonical_url(contributions_url) %>
 <% else %>
   <% the_title = "Contribuciones de Programas de La Venganza será Terrible (página #{params[:page]})" -%>
+  <%- canonical_url(contributions_url + "/page/" + params[:page]) %>
 <% end %>
 <% page_title the_title -%>
 <% meta_description strip_tags(the_title) -%>

app/views/posts/index.html.erb

@@ -1,7 +1,9 @@
 <% if params[:page].present? %>
   <% the_title = "Programas de La Venganza será Terrible de Alejandro Dolina (página #{params[:page]})" -%>
+  <%- canonical_url(posts_url + "/page/" + params[:page]) %>
 <% else %>
   <% the_title = "Programas de La Venganza será Terrible de Alejandro Dolina" -%>
+  <%- canonical_url(posts_url) %>
 <% end %>
 <% page_title the_title -%>
 <% meta_description strip_tags(the_title) -%>

app/views/posts/show.html.erb

@@ -4,6 +4,7 @@
   <% page_title @post.title + " - Página #{params[:page]} de comentarios" -%>
 <% end %>
 <% meta_description @post.description, 'article' -%>
+<%- canonical_url(post_url @post) %>
 <div class="level is-mobile">
   <% if prev_post = @post.previous %>
     <div class="level-left">

app/views/users/show.html.erb

@@ -1,7 +1,9 @@
 <% if params[:page].nil? %>
   <% the_title = "Perfil de #{@user.alias}" -%>
+  <%- canonical_url(user_url @user) %>
 <% else %>
   <% the_title = "Perfil de #{@user.alias} - Página #{params[:page]} de comentarios" -%>
+  <%- canonical_url(comments_user_path(@user) + "/page/" + params[:page]) %>
 <% end %>
 <% page_title the_title -%>
 <% meta_description the_title + " en Venganzas del Pasado", 'profile' -%>