rosa-build/app/models/concerns/acts_like_member.rb

module ActsLikeMember
  extend ActiveSupport::Concern

  included do
    scope :not_member_of, ->(item) {
      where("
        #{table_name}.id NOT IN (
          SELECT relations.actor_id
          FROM relations
          WHERE (
            relations.actor_type = '#{self.to_s}'
            AND relations.target_type = '#{item.class.to_s}'
            AND relations.target_id = #{item.id}
          )
        )
      ")
    }
    scope :search_order, ->    { order("CHAR_LENGTH(#{table_name}.uname) ASC") }
    scope :without,      ->(a) { where("#{table_name}.id NOT IN (?)", a) }
    scope :by_uname,     ->(n) { where("#{table_name}.uname ILIKE ?", n) }
    scope :search,       ->(q) { by_uname("%#{q.to_s.strip}%") }
  end

  def to_param
    uname
  end

  module ClassMethods
    def find_by_insensitive_uname(uname)
      find_by(uname: uname) || by_uname(uname).first
    end

    def find_by_insensitive_uname!(uname)
      find_by_insensitive_uname(uname) or raise ActiveRecord::RecordNotFound
    end
  end
end