active_record_extensions.rb

来自「ruby on rails web敏捷开发之路第二版 源代码」· RB 代码 · 共 45 行

#---
# Excerpted from "Agile Web Development with Rails, 2nd Ed."
# We make no guarantees that this code is fit for any purpose. 
# Visit http://www.pragmaticprogrammer.com/titles/rails2 for more book information.
#---
module Relevance
  module ActiveRecordExtensions
    def user_columns
      self.content_columns.find_all do |d|
        !d.name.match /(_at|_on|position|lock_version|_id|password_hash)$/
      end
    end
    def find_by_like(value, *columns)
      self.find(:all, :conditions=>conditions_by_like(value, *columns))
    end
    def find_by_criteria(template)
      self.find(:all, :conditions=>conditions_by_criteria(template))      
    end
    
    def conditions_by_like(value, *columns)
      columns = self.user_columns if columns.size==0
      columns = columns[0] if columns[0].kind_of?(Array)
      conditions = columns.map {|c|
        c = c.name if c.kind_of? ActiveRecord::ConnectionAdapters::Column
        "`#{c}` LIKE " + ActiveRecord::Base.connection.quote("%#{value}%")
      }.join(" OR ")
    end
    
    def conditions_by_criteria(template)
      attrs = template.class.columns.map &:name
      vals = []
      attrs.each {|a| vals << "`#{a}` LIKE " + ActiveRecord::Base.connection.quote("%#{template.send(a)}%") if !template.send(a).blank? && a != 'id' && a != 'lock_version' }
      vals.join(" AND ")
    end
    def has_manies()
      self.reflect_on_all_associations.select {|x| x.macro == :has_many || x.macro == :has_and_belongs_to_many}
    end
    def has_ones()
      self.reflect_on_all_associations.select {|x| x.macro == :has_one || x.macro == :belongs_to}
    end
  end
end

ActiveRecord::Base.extend Relevance::ActiveRecordExtensions