vendor/rails/activerecord/lib/active_record/associations/has_one_association.rb

   1 module ActiveRecord
   2   module Associations
   3     class HasOneAssociation < BelongsToAssociation #:nodoc:
   4       def initialize(owner, reflection)
   5         super
   6         construct_sql
   7       end
   8
   9       def create(attrs = {}, replace_existing = true)
  10         new_record(replace_existing) do |reflection|
  11           reflection.create_association(attrs)
  12         end
  13       end
  14
  15       def create!(attrs = {}, replace_existing = true)
  16         new_record(replace_existing) do |reflection|
  17           reflection.create_association!(attrs)
  18         end
  19       end
  20
  21       def build(attrs = {}, replace_existing = true)
  22         new_record(replace_existing) do |reflection|
  23           reflection.build_association(attrs)
  24         end
  25       end
  26
  27       def replace(obj, dont_save = false)
  28         load_target
  29
  30         unless @target.nil? || @target == obj
  31           if dependent? && !dont_save
  32             case @reflection.options[:dependent]
  33             when :delete
  34               @target.delete unless @target.new_record?
  35               @owner.clear_association_cache
  36             when :destroy
  37               @target.destroy unless @target.new_record?
  38               @owner.clear_association_cache
  39             when :nullify
  40               @target[@reflection.primary_key_name] = nil
  41               @target.save unless @owner.new_record? || @target.new_record?
  42             end
  43           else
  44             @target[@reflection.primary_key_name] = nil
  45             @target.save unless @owner.new_record? || @target.new_record?
  46           end
  47         end
  48
  49         if obj.nil?
  50           @target = nil
  51         else
  52           raise_on_type_mismatch(obj)
  53           set_belongs_to_association_for(obj)
  54           @target = (AssociationProxy === obj ? obj.target : obj)
  55         end
  56
  57         @loaded = true
  58
  59         unless @owner.new_record? or obj.nil? or dont_save
  60           return (obj.save ? self : false)
  61         else
  62           return (obj.nil? ? nil : self)
  63         end
  64       end
  65
  66       protected
  67         def owner_quoted_id
  68           if @reflection.options[:primary_key]
  69             @owner.class.quote_value(@owner.send(@reflection.options[:primary_key]))
  70           else
  71             @owner.quoted_id
  72           end
  73         end
  74
  75       private
  76         def find_target
  77           @reflection.klass.find(:first,
  78             :conditions => @finder_sql,
  79             :select     => @reflection.options[:select],
  80             :order      => @reflection.options[:order],
  81             :include    => @reflection.options[:include],
  82             :readonly   => @reflection.options[:readonly]
  83           )
  84         end
  85
  86         def construct_sql
  87           case
  88             when @reflection.options[:as]
  89               @finder_sql =
  90                 "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_id = #{owner_quoted_id} AND " +
  91                 "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote_value(@owner.class.base_class.name.to_s)}"
  92             else
  93               @finder_sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"
  94           end
  95           @finder_sql << " AND (#{conditions})" if conditions
  96         end
  97
  98         def construct_scope
  99           create_scoping = {}
 100           set_belongs_to_association_for(create_scoping)
 101           { :create => create_scoping }
 102         end
 103
 104         def new_record(replace_existing)
 105           # Make sure we load the target first, if we plan on replacing the existing
 106           # instance. Otherwise, if the target has not previously been loaded
 107           # elsewhere, the instance we create will get orphaned.
 108           load_target if replace_existing
 109           record = @reflection.klass.send(:with_scope, :create => construct_scope[:create]) do
 110             yield @reflection
 111           end
 112
 113           if replace_existing
 114             replace(record, true)
 115           else
 116             record[@reflection.primary_key_name] = @owner.id unless @owner.new_record?
 117             self.target = record
 118           end
 119
 120           record
 121         end
 122     end
 123   end
 124 end