[feature] ability to set OG image on a per page basis

app/models/comfy/cms/page.rb

@@ -0,0 +1,175 @@
+# frozen_string_literal: true
+
+class Comfy::Cms::Page < ActiveRecord::Base
+
+  self.table_name = "comfy_cms_pages"
+
+  include Comfy::Cms::WithFragments
+  include Comfy::Cms::WithCategories
+
+  cms_acts_as_tree counter_cache: :children_count, order: :position
+  cms_has_revisions_for :fragments_attributes
+
+  attr_accessor :content
+
+  # -- Relationships -----------------------------------------------------------
+  belongs_to :site
+  belongs_to :target_page,
+    class_name: "Comfy::Cms::Page",
+    optional:   true
+
+  has_many :translations,
+    dependent: :destroy
+
+  # page specific OG image feature
+
+  has_one_attached :og_image
+
+
+  # -- Callbacks ---------------------------------------------------------------
+  before_validation :assigns_label,
+                    :assign_parent,
+                    :escape_slug,
+                    :assign_full_path
+  before_create     :assign_position
+  after_save        :sync_child_full_paths!
+  after_find        :unescape_slug_and_path
+
+  # -- Validations -------------------------------------------------------------
+  validates :label,
+    presence:   true
+  validates :slug,
+    presence:   true,
+    uniqueness: { scope: :parent_id },
+    unless:     ->(p) {
+      p.site && (p.site.pages.count.zero? || p.site.pages.root == self)
+    }
+  validate :validate_target_page
+  validate :validate_format_of_unescaped_slug
+
+  # -- Scopes ------------------------------------------------------------------
+  scope :published, -> { where(is_published: true) }
+
+  # -- Class Methods -----------------------------------------------------------
+  # Tree-like structure for pages
+  def self.options_for_select(site:, current_page: nil, exclude_self: false)
+    options = []
+
+    options_for_page = ->(page, depth = 0) do
+      return if page.nil?
+      return if exclude_self && page == current_page
+
+      options << ["#{'. . ' * depth}#{page.label}", page.id]
+
+      page.children.order(:position).each do |child_page|
+        options_for_page.call(child_page, depth + 1)
+      end
+    end
+
+    options_for_page.call(site.pages.root)
+
+    options
+  end
+
+  # -- Instance Methods --------------------------------------------------------
+  # For previewing purposes sometimes we need to have full_path set. This
+  # full path take care of the pages and its childs but not of the site path
+  def full_path
+    read_attribute(:full_path) || assign_full_path
+  end
+
+  # Somewhat unique method of identifying a page that is not a full_path
+  def identifier
+    parent_id.blank? ? "index" : full_path[1..-1].parameterize
+  end
+
+  # Full url for a page
+  def url(relative: false)
+    [site.url(relative: relative), full_path].compact.join
+  end
+
+  # This method will mutate page object by transfering attributes from translation
+  # for a given locale.
+  def translate!
+    # If site locale same as page's or there's no translastions, we do nothing
+    if site.locale == I18n.locale.to_s || translations.blank?
+      return
+    end
+
+    translation = translations.published.find_by!(locale: I18n.locale)
+    self.layout        = translation.layout
+    self.label         = translation.label
+    self.content_cache = translation.content_cache
+
+    # We can't just assign fragments as it's a relation and will write to DB
+    # This has odd side-effect of preserving page's fragments and just replacing
+    # them from the translation. Not an issue if all fragments match.
+    self.fragments_attributes = translation.fragments_attributes
+    readonly!
+
+    self
+  end
+
+protected
+
+  def assigns_label
+    self.label = label.blank? ? slug.try(:titleize) : label
+  end
+
+  def assign_parent
+    return unless site
+    self.parent ||= site.pages.root unless self == site.pages.root || site.pages.count.zero?
+  end
+
+  def assign_full_path
+    self.full_path =
+      if self.parent
+        [CGI.escape(self.parent.full_path).gsub("%2F", "/"), slug].join("/").squeeze("/")
+      else
+        "/"
+      end
+  end
+
+  def assign_position
+    return unless self.parent
+    return if position.to_i.positive?
+    max = self.parent.children.maximum(:position)
+    self.position = max ? max + 1 : 0
+  end
+
+  def validate_target_page
+    return unless target_page
+    p = self
+    while p.target_page
+      if (p = p.target_page) == self
+        return errors.add(:target_page_id, "Invalid Redirect")
+      end
+    end
+  end
+
+  def validate_format_of_unescaped_slug
+    return unless slug.present?
+    unescaped_slug = CGI.unescape(slug)
+    errors.add(:slug, :invalid) unless unescaped_slug =~ %r{^\p{Alnum}[\.\p{Alnum}\p{Mark}_-]*$}i
+  end
+
+  # Forcing re-saves for child pages so they can update full_paths
+  def sync_child_full_paths!
+    return unless full_path_previously_changed?
+    children.each do |p|
+      p.update_attribute(:full_path, p.send(:assign_full_path))
+    end
+  end
+
+  # Escape slug unless it's nonexistent (root)
+  def escape_slug
+    self.slug = CGI.escape(slug) unless slug.nil?
+  end
+
+  # Unescape the slug and full path back into their original forms unless they're nonexistent
+  def unescape_slug_and_path
+    self.slug       = CGI.unescape(slug)      unless slug.nil?
+    self.full_path  = CGI.unescape(full_path) unless full_path.nil?
+  end
+
+end

app/views/comfy/admin/cms/partials/_page_form_inner.haml

@@ -1,4 +1,11 @@
 .form-group
   = form.check_box :is_restricted
 .form-group
-  = form.text_area :preview_content, data: {'cms-cm-mode' => 'text/html'}
+  = form.text_area :preview_content, data: {'cms-cm-mode' => 'text/html'}
+.form-group
+  = form.file_field :og_image, class: 'form-control', data: {'cms-cm-mode' => 'text/html'}, label: false
+- if form.object.og_image.present?
+  .form-group.text-right
+    = image_tag(url_for(form.object.og_image), class: 'img-thumbnail', width: '100', height: 'auto') 
+
+

app/views/shared/_meta_tags.html.erb

@@ -1,4 +1,5 @@
-<% og_image = og_image_url(Subdomain.current) %>
+<% og_image = @cms_page.present? && @cms_page.og_image.attached? ? rails_blob_url(@cms_page.og_image) : og_image_url(Subdomain.current) %>
+
 <% set_meta_tags      site: forum_html_title(Subdomain.current),
                       title: html_title(Subdomain.current),
                       description: site_description(Subdomain.current),