Merge pull request #2059 from tf/href-lang

Entry translations/hreflang alternate links

.hound.yml

@@ -1,5 +1,6 @@
 ruby:
   config_file: .rubocop.yml
+  enabled: false
 javascript:
   config_file: .jshintrc
   ignore_file: .jshintignore

.rubocop.yml

@@ -1,5 +1,5 @@
 AllCops:
-  TargetRubyVersion: 2.5
+  TargetRubyVersion: 3.2
 
 # Use double quotes only for interpolation.
 Style/StringLiterals:
@@ -14,7 +14,7 @@ Style/BlockDelimiters:
   EnforcedStyle: braces_for_chaining
 
 # The default of 80 characters is a little to narrow.
-Metrics/LineLength:
+Layout/LineLength:
   Max: 100
 
 # Only place spaces inside blocks written with braces.
@@ -48,19 +48,21 @@ Metrics/BlockLength:
 # In specs methods using RSpec DSL often become long
 Metrics/MethodLength:
   Exclude:
+    - '**/app/views/components/**/*'
     - '**/spec/**/*'
 
 # Long spec files are ok
 Metrics/ModuleLength:
   Exclude:
     - '**/spec/**/*'
 
-Metricts/ParameterLists:
+Metrics/ParameterLists:
   CountKeywordArgs: false
 
 # Do not require class documentation for specs and migrations
 Style/Documentation:
   Exclude:
+    - admins/**/*
     - '**/spec/**/*'
     - db/migrate/*
 
@@ -79,7 +81,3 @@ Style/ModuleFunction:
 # Allow method names like has_text?
 Naming/PredicateName:
   Enabled: false
-
-# Braces can have meaning in Ruby 3
-Style/BracesAroundHashParameters:
-  Enabled: false

Gemfile

@@ -31,3 +31,6 @@ gem 'shakapacker', '~> 7.0'
 
 # Make tests fail on JS errors
 gem 'capybara-chromedriver-logger', git: 'https://github.com/codevise/capybara-chromedriver-logger', branch: 'fix-selenium-4-deprecation', require: false
+
+# See https://github.com/charkost/prosopite/pull/79
+gem 'prosopite', git: 'https://github.com/tf/prosopite', branch: 'location-backtrace-cleaner'

admins/pageflow/entry.rb

@@ -205,6 +205,7 @@ module Pageflow
       helper Admin::FormHelper
       helper Admin::MembershipsHelper
       helper Admin::RevisionsHelper
+      helper Admin::EntryTranslationsHelper
 
       helper_method :account_policy_scope
       helper_method :site_policy_scope

admins/pageflow/translations.rb

@@ -0,0 +1,75 @@
+module Pageflow
+  ActiveAdmin.register Entry, as: 'Translations' do
+    menu false
+    belongs_to :entry
+
+    actions :new, :create, :destroy
+
+    searchable_select_options(name: :potential_entry_translations,
+                              scope: lambda do |_params|
+                                authorize!(:manage_translations, parent)
+                                PotentialEntryTranslations.for(parent).resolve
+                              end,
+                              text_attribute: :title,
+                              display_text: lambda do |entry|
+                                if entry.translation_group
+                                  entry.translation_group
+                                    .entries
+                                    .order('title ASC')
+                                    .map(&:title)
+                                    .join(' / ')
+                                    .presence
+                                else
+                                  entry.title
+                                end
+                              end)
+
+    form partial: 'form'
+
+    member_action :default, method: :put do
+      entry = Entry.find(params[:id])
+
+      authorize!(:manage_translations, entry)
+      entry.mark_as_default_translation
+
+      redirect_to(admin_entry_path(parent, tab: 'translations'))
+    end
+
+    controller do
+      helper Pageflow::Admin::FormHelper
+
+      def index
+        redirect_to admin_entry_path(parent, tab: 'translations')
+      end
+
+      def create
+        entry = Entry.find(params.require(:entry)[:id])
+
+        authorize!(:manage_translations, parent)
+        authorize!(:manage_translations, entry)
+        parent.mark_as_translation_of(entry)
+
+        redirect_to(admin_entry_path(parent, tab: 'translations'))
+      end
+
+      def destroy
+        entry = Entry.find(params[:id])
+
+        authorize!(:manage_translations, entry)
+        entry.remove_from_translation_group
+
+        redirect_to(admin_entry_path(parent, tab: 'translations'))
+      end
+
+      protected
+
+      def authorized?(action, subject = nil)
+        if subject.is_a?(Entry) && subject.new_record?
+          super(:manage_translations, parent)
+        else
+          super
+        end
+      end
+    end
+  end
+end

app/assets/stylesheets/pageflow/admin/entries/index_table.scss

@@ -1,4 +1,5 @@
-.index_table {
+.index_table,
+.embedded_index_table {
   .publication_state {
     width: 16px;
     padding: 5px;

app/helpers/pageflow/admin/entry_translations_helper.rb

@@ -0,0 +1,19 @@
+module Pageflow
+  module Admin
+    # @api private
+    module EntryTranslationsHelper
+      def entry_translation_display_locale(entry)
+        display_locale = t(
+          'pageflow.public._language',
+          locale: (entry.published_revision || entry.draft).locale
+        )
+
+        if entry.default_translation?
+          t('pageflow.admin.entry_translations.default_translation', display_locale:)
+        else
+          display_locale
+        end
+      end
+    end
+  end
+end

app/helpers/pageflow/hreflang_links_helper.rb

@@ -0,0 +1,34 @@
+module Pageflow
+  # Helpers to render alternate links to translations of an entry.
+  #
+  # @since edge
+  module HreflangLinksHelper
+    include SocialShareHelper
+
+    # Render alternate links to all published entries that have been
+    # marked as translations of the given entry.
+    def hreflang_link_tags_for_entry(entry)
+      translations =
+        entry.translations(-> { preload(:site, :translation_group, permalink: :directory) })
+
+      safe_join(
+        translations.each_with_object([]) do |translation, links|
+          links << hreflang_link_tag(translation)
+
+          if translation.default_translation?
+            links << hreflang_link_tag(translation, hreflang: 'x-default')
+          end
+        end
+      )
+    end
+
+    private
+
+    def hreflang_link_tag(entry, hreflang: entry.locale)
+      tag('link',
+          rel: 'alternate',
+          hreflang:,
+          href: social_share_entry_url(entry))
+    end
+  end
+end

app/models/concerns/pageflow/translatable.rb

@@ -0,0 +1,62 @@
+module Pageflow
+  # @api private
+  module Translatable
+    extend ActiveSupport::Concern
+
+    included do
+      belongs_to(:translation_group,
+                 optional: true,
+                 class_name: 'EntryTranslationGroup')
+
+      has_many(:translations,
+               through: :translation_group,
+               source: :entries)
+
+      after_destroy do
+        if translation_group&.single_item_or_empty?
+          translation_group.destroy
+        elsif default_translation?
+          translation_group.update(default_translation: nil)
+        end
+      end
+    end
+
+    def mark_as_translation_of(entry)
+      transaction do
+        ensure_translation_group(entry)
+
+        if !entry.translation_group
+          entry.update!(translation_group:)
+        elsif entry.translation_group != translation_group
+          entry.translation_group.merge_into(translation_group)
+        end
+      end
+    end
+
+    def remove_from_translation_group
+      if translation_group.entries.count <= 2
+        translation_group.destroy
+      else
+        translation_group.update(default_translation: nil) if default_translation?
+        update!(translation_group: nil)
+      end
+    end
+
+    def mark_as_default_translation
+      translation_group.update!(default_translation: self)
+    end
+
+    def default_translation?
+      translation_group&.default_translation == self
+    end
+
+    private
+
+    def ensure_translation_group(other_entry)
+      return if translation_group
+
+      update!(translation_group: other_entry.translation_group ||
+              build_translation_group(default_translation: self))
+    end
+  end
+end

app/models/pageflow/entry.rb

@@ -7,6 +7,7 @@ class PasswordMissingError < StandardError
     include EntryPublicationStates
     include Permalinkable
     include SerializationBlacklist
+    include Translatable
 
     extend FriendlyId
     friendly_id :slug_candidates, :use => [:finders, :slugged]

app/models/pageflow/entry_translation_group.rb

@@ -0,0 +1,27 @@
+module Pageflow
+  # @api private
+  class EntryTranslationGroup < ApplicationRecord
+    has_many :entries,
+             -> { order(title: :asc) },
+             foreign_key: 'translation_group_id',
+             dependent: :nullify
+
+    has_many :publicly_visible_entries,
+             -> { published_without_password_protection.published_without_noindex },
+             foreign_key: 'translation_group_id',
+             class_name: 'Entry'
+
+    belongs_to :default_translation,
+               class_name: 'Entry',
+               optional: true
+
+    def merge_into(translation_group)
+      entries.update_all(translation_group_id: translation_group.id)
+      destroy
+    end
+
+    def single_item_or_empty?
+      !entries.many?
+    end
+  end
+end

app/models/pageflow/potential_entry_translations.rb

@@ -0,0 +1,55 @@
+module Pageflow
+  # @api private
+  class PotentialEntryTranslations
+    def initialize(entry)
+      @entry = entry
+    end
+
+    def self.for(entry)
+      new(entry)
+    end
+
+    def resolve
+      preload(
+        group_by_translation_group(
+          exclude_translations(
+            other_entries_of_account
+          )
+        )
+      )
+    end
+
+    private
+
+    def other_entries_of_account
+      @entry.account.entries.where.not(id: @entry.id)
+    end
+
+    def exclude_translations(scope)
+      return scope unless @entry.translation_group
+
+      scope
+        .where.not(translation_group_id: @entry.translation_group)
+        .or(scope.where(translation_group: nil))
+    end
+
+    def group_by_translation_group(scope)
+      scope
+        # Use MIN(id) to choose an arbitrary entry to represent its
+        # translation group. MIN(translation_group_id) is needed since
+        # technically translation_group_id is not part of the GROUP BY
+        # clause.
+        .select(<<-SQL)
+          MIN(id) as id,
+          GROUP_CONCAT(title) as title,
+          MIN(translation_group_id) as translation_group_id
+        SQL
+        .group('IFNULL(translation_group_id, id)')
+        .order('title ASC')
+    end
+
+    def preload(scope)
+      scope.includes(translation_group: :entries)
+    end
+  end
+end