Class: BookmarkQuery

Inherits:
Object
  • Object
show all
Defined in:
lib/bookmark_query.rb

Overview

Allows us to query Bookmark records for lists. Used mainly in the user/activity/bookmarks page.

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(user:, guardian: nil, search_term: nil, page: nil, per_page: nil) ⇒ BookmarkQuery

Returns a new instance of BookmarkQuery.



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# File 'lib/bookmark_query.rb', line 29

def initialize(user:, guardian: nil, search_term: nil, page: nil, per_page: nil)
  @user = user
  @search_term = search_term
  @guardian = guardian || Guardian.new(@user)
  @page = page ? page.to_i : 0
  @per_page = per_page ? per_page.to_i : 20
  @count = 0
end

Instance Attribute Details

#countObject (readonly)

Returns the value of attribute count.



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# File 'lib/bookmark_query.rb', line 27

def count
  @count
end

#guardianObject (readonly)

Returns the value of attribute guardian.



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# File 'lib/bookmark_query.rb', line 27

def guardian
  @guardian
end

Class Method Details

.on_preload(&blk) ⇒ Object



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# File 'lib/bookmark_query.rb', line 8

def self.on_preload(&blk)
  (@preload ||= Set.new) << blk
end

.preload(bookmarks, object) ⇒ Object



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# File 'lib/bookmark_query.rb', line 12

def self.preload(bookmarks, object)
  preload_polymorphic_associations(bookmarks, object.guardian)
  @preload.each { |preload| preload.call(bookmarks, object) } if @preload
end

.preload_polymorphic_associations(bookmarks, guardian) ⇒ Object

These polymorphic associations are loaded to make the UserBookmarkListSerializer’s life easier, which conditionally chooses the bookmark serializer to use based on the type, and we want the associations all loaded ahead of time to make sure we are not doing N+1s.



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# File 'lib/bookmark_query.rb', line 21

def self.preload_polymorphic_associations(bookmarks, guardian)
  Bookmark.registered_bookmarkables.each do |registered_bookmarkable|
    registered_bookmarkable.perform_preload(bookmarks, guardian)
  end
end

Instance Method Details

#list_all(&blk) ⇒ Object



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# File 'lib/bookmark_query.rb', line 38

def list_all(&blk)
  ts_query = @search_term.present? ? Search.ts_query(term: @search_term) : nil
  search_term_wildcard = @search_term.present? ? "%#{@search_term}%" : nil

  queries =
    Bookmark
      .registered_bookmarkables
      .map do |bookmarkable|
        interim_results = bookmarkable.perform_list_query(@user, @guardian)

        # this could occur if there is some security reason that the user cannot
        # access the bookmarkables that they have bookmarked, e.g. if they had 1 bookmark
        # on a topic and that topic was moved into a private category
        next if interim_results.blank?

        if @search_term.present?
          interim_results =
            bookmarkable.perform_search_query(interim_results, search_term_wildcard, ts_query)
        end

        # this is purely to make the query easy to read and debug, otherwise it's
        # all mashed up into a massive ball in MiniProfiler :)
        "---- #{bookmarkable.model} bookmarkable ---\n\n #{interim_results.to_sql}"
      end
      .compact

  # same for interim results being blank, the user might have been locked out
  # from all their various bookmarks, in which case they will see nothing and
  # no further pagination/ordering/etc is required
  return [] if queries.empty?

  union_sql = queries.join("\n\nUNION\n\n")
  results = Bookmark.select("bookmarks.*").from("(\n\n#{union_sql}\n\n) as bookmarks")
  results =
    results.order(
      "(CASE WHEN bookmarks.pinned THEN 0 ELSE 1 END),
      bookmarks.reminder_at ASC,
      bookmarks.updated_at DESC",
    )

  @count = results.count

  results = results.offset(@page * @per_page) if @page.positive?

  if updated_results = blk&.call(results)
    results = updated_results
  end

  results = results.limit(@per_page).to_a

  BookmarkQuery.preload(results, self)
  results
end

#unread_notifications(limit: 20) ⇒ Object



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# File 'lib/bookmark_query.rb', line 92

def unread_notifications(limit: 20)
  reminder_notifications =
    Notification
      .for_user_menu(@user.id, limit: [limit, 100].min)
      .unread
      .where(notification_type: Notification.types[:bookmark_reminder])

  reminder_bookmark_ids = reminder_notifications.map { |n| n.data_hash[:bookmark_id] }.compact

  # We preload associations like we do above for the list to avoid
  # N1s in the can_see? guardian calls for each bookmark.
  bookmarks = Bookmark.where(user: @user, id: reminder_bookmark_ids)
  BookmarkQuery.preload(bookmarks, self)

  # Any bookmarks that no longer exist, we need to find the associated
  # records using bookmarkable details.
  #
  # First we want to group these by type into a hash to reduce queries:
  #
  # {
  #   "Post": {
  #     1234: <Post>,
  #     566: <Post>,
  #   },
  #   "Topic": {
  #     123: <Topic>,
  #     99: <Topic>,
  #   }
  # }
  #
  # We may not need to do this most of the time. It depends mostly on
  # a user's auto_delete_preference for bookmarks.
  deleted_bookmark_ids = reminder_bookmark_ids - bookmarks.map(&:id)
  deleted_bookmarkables =
    reminder_notifications
      .select do |notif|
        deleted_bookmark_ids.include?(notif.data_hash[:bookmark_id]) &&
          notif.data_hash[:bookmarkable_type].present?
      end
      .inject({}) do |hash, notif|
        hash[notif.data_hash[:bookmarkable_type]] ||= {}
        hash[notif.data_hash[:bookmarkable_type]][notif.data_hash[:bookmarkable_id]] = nil
        hash
      end

  # Then, we can actually find the associated records for each type in the database.
  deleted_bookmarkables.each do |type, bookmarkable|
    records = Bookmark.registered_bookmarkable_from_type(type).model.where(id: bookmarkable.keys)
    records.each { |record| deleted_bookmarkables[type][record.id] = record }
  end

  reminder_notifications.select do |notif|
    bookmark = bookmarks.find { |bm| bm.id == notif.data_hash[:bookmark_id] }

    # This is the happy path, it's easiest to look up using a bookmark
    # that hasn't been deleted.
    if bookmark.present?
      bookmarkable = Bookmark.registered_bookmarkable_from_type(bookmark.bookmarkable_type)
      bookmarkable.can_see?(@guardian, bookmark)
    else
      # Otherwise, we have to use our cached records from the deleted
      # bookmarks' related bookmarkable (e.g. Post, Topic) to determine
      # secure access.
      bookmarkable =
        deleted_bookmarkables.dig(
          notif.data_hash[:bookmarkable_type],
          notif.data_hash[:bookmarkable_id],
        )
      bookmarkable.present? &&
        Bookmark.registered_bookmarkable_from_type(
          notif.data_hash[:bookmarkable_type],
        ).can_see_bookmarkable?(@guardian, bookmarkable)
    end
  end
end