Contents

module AutoIncrement
  class Incrementor
    def initialize(options = {})
       @options = options.reverse_merge  column: :code, scope: nil, initial: 1, force: false
       @options[:scope] = [ @options[:scope] ] unless @options[:scope].is_a? Array
    end

    def before_create(record)
      @record = record
      write if can_write?
    end

    private

    def can_write?
      @record.send(@options[:column]).blank? or @options[:force]
    end

    def write
      @record.send :write_attribute, @options[:column], increment
    end

    def build_scopes(query)
      @options[:scope].each do |scope|
        if scope.present? and @record.respond_to?(scope)
          query = query.where(scope => @record.send(scope))
        end
      end

      query
    end

    def maximum
      query = build_scopes @record.class

      if @options[:initial].class == String
        query.select("#{@options[:column]} max").order("LENGTH(#{@options[:column]}) DESC, #{@options[:column]} DESC").first.try :max
      else
        query.maximum @options[:column]
      end
    end

    def increment
      max = maximum

      max.blank? ? @options[:initial] : max.next
    end
  end
end

Version data entries

2 entries across 2 versions & 1 rubygems

Version	Path
auto_increment-1.1.1	lib/auto_increment/incrementor.rb
auto_increment-1.1.0	lib/auto_increment/incrementor.rb