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             @target.destroy unless @target.new_record?
  33             @owner.clear_association_cache
  34           else
  35             @target[@reflection.primary_key_name] = nil
  36             @target.save unless @owner.new_record? || @target.new_record?
  37           end
  38         end
  39
  40         if obj.nil?
  41           @target = nil
  42         else
  43           raise_on_type_mismatch(obj)
  44           set_belongs_to_association_for(obj)
  45           @target = (AssociationProxy === obj ? obj.target : obj)
  46         end
  47
  48         @loaded = true
  49
  50         unless @owner.new_record? or obj.nil? or dont_save
  51           return (obj.save ? self : false)
  52         else
  53           return (obj.nil? ? nil : self)
  54         end
  55       end
  56
  57       protected
  58         def owner_quoted_id
  59           if @reflection.options[:primary_key]
  60             @owner.class.quote_value(@owner.send(@reflection.options[:primary_key]))
  61           else
  62             @owner.quoted_id
  63           end
  64         end
  65
  66       private
  67         def find_target
  68           @reflection.klass.find(:first,
  69             :conditions => @finder_sql,
  70             :select     => @reflection.options[:select],
  71             :order      => @reflection.options[:order],
  72             :include    => @reflection.options[:include],
  73             :readonly   => @reflection.options[:readonly]
  74           )
  75         end
  76
  77         def construct_sql
  78           case
  79             when @reflection.options[:as]
  80               @finder_sql =
  81                 "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_id = #{owner_quoted_id} AND " +
  82                 "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote_value(@owner.class.base_class.name.to_s)}"
  83             else
  84               @finder_sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"
  85           end
  86           @finder_sql << " AND (#{conditions})" if conditions
  87         end
  88
  89         def construct_scope
  90           create_scoping = {}
  91           set_belongs_to_association_for(create_scoping)
  92           { :create => create_scoping }
  93         end
  94
  95         def new_record(replace_existing)
  96           # Make sure we load the target first, if we plan on replacing the existing
  97           # instance. Otherwise, if the target has not previously been loaded
  98           # elsewhere, the instance we create will get orphaned.
  99           load_target if replace_existing
 100           record = @reflection.klass.send(:with_scope, :create => construct_scope[:create]) do
 101             yield @reflection
 102           end
 103
 104           if replace_existing
 105             replace(record, true)
 106           else
 107             record[@reflection.primary_key_name] = @owner.id unless @owner.new_record?
 108             self.target = record
 109           end
 110
 111           record
 112         end
 113     end
 114   end
 115 end