ruby/lib/ruby/gems/1.8/gems/activerecord-2.3.11/lib/active_record/associations/belongs_to_association.rb

   1 module ActiveRecord
   2   module Associations
   3     class BelongsToAssociation < AssociationProxy #:nodoc:
   4       def create(attributes = {})
   5         replace(@reflection.create_association(attributes))
   6       end
   7
   8       def build(attributes = {})
   9         replace(@reflection.build_association(attributes))
  10       end
  11
  12       def replace(record)
  13         counter_cache_name = @reflection.counter_cache_column
  14
  15         if record.nil?
  16           if counter_cache_name && !@owner.new_record?
  17             @reflection.klass.decrement_counter(counter_cache_name, previous_record_id) if @owner[@reflection.primary_key_name]
  18           end
  19
  20           @target = @owner[@reflection.primary_key_name] = nil
  21         else
  22           raise_on_type_mismatch(record)
  23
  24           if counter_cache_name && !@owner.new_record?
  25             @reflection.klass.increment_counter(counter_cache_name, record.id)
  26             @reflection.klass.decrement_counter(counter_cache_name, @owner[@reflection.primary_key_name]) if @owner[@reflection.primary_key_name]
  27           end
  28
  29           @target = (AssociationProxy === record ? record.target : record)
  30           @owner[@reflection.primary_key_name] = record_id(record) unless record.new_record?
  31           @updated = true
  32         end
  33
  34         set_inverse_instance(record, @owner)
  35
  36         loaded
  37         record
  38       end
  39
  40       def updated?
  41         @updated
  42       end
  43
  44       private
  45         def find_target
  46           find_method = if @reflection.options[:primary_key]
  47                           "find_by_#{@reflection.options[:primary_key]}"
  48                         else
  49                           "find"
  50                         end
  51           the_target = @reflection.klass.send(find_method,
  52             @owner[@reflection.primary_key_name],
  53             :select     => @reflection.options[:select],
  54             :conditions => conditions,
  55             :include    => @reflection.options[:include],
  56             :readonly   => @reflection.options[:readonly]
  57           ) if @owner[@reflection.primary_key_name]
  58           set_inverse_instance(the_target, @owner)
  59           the_target
  60         end
  61
  62         def foreign_key_present
  63           !@owner[@reflection.primary_key_name].nil?
  64         end
  65
  66         def record_id(record)
  67           record.send(@reflection.options[:primary_key] || :id)
  68         end
  69
  70         def previous_record_id
  71           @previous_record_id ||= if @reflection.options[:primary_key]
  72                                     previous_record = @owner.send(@reflection.name)
  73                                     previous_record.nil? ? nil : previous_record.id
  74                                   else
  75                                     @owner[@reflection.primary_key_name]
  76                                   end
  77         end
  78
  79         # NOTE - for now, we're only supporting inverse setting from belongs_to back onto
  80         # has_one associations.
  81         def we_can_set_the_inverse_on_this?(record)
  82           @reflection.has_inverse? && @reflection.inverse_of.macro == :has_one
  83         end
  84     end
  85   end
  86 end