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

   1 module ActiveRecord
   2   module Associations
   3     # This is the proxy that handles a has many association.
   4     #
   5     # If the association has a <tt>:through</tt> option further specialization
   6     # is provided by its child HasManyThroughAssociation.
   7     class HasManyAssociation < AssociationCollection #:nodoc:
   8       protected
   9         def owner_quoted_id
  10           if @reflection.options[:primary_key]
  11             quote_value(@owner.send(@reflection.options[:primary_key]))
  12           else
  13             @owner.quoted_id
  14           end
  15         end
  16
  17         # Returns the number of records in this collection.
  18         #
  19         # If the association has a counter cache it gets that value. Otherwise
  20         # it will attempt to do a count via SQL, bounded to <tt>:limit</tt> if
  21         # there's one.  Some configuration options like :group make it impossible
  22         # to do a SQL count, in those cases the array count will be used.
  23         #
  24         # That does not depend on whether the collection has already been loaded
  25         # or not. The +size+ method is the one that takes the loaded flag into
  26         # account and delegates to +count_records+ if needed.
  27         #
  28         # If the collection is empty the target is set to an empty array and
  29         # the loaded flag is set to true as well.
  30         def count_records
  31           count = if has_cached_counter?
  32             @owner.send(:read_attribute, cached_counter_attribute_name)
  33           elsif @reflection.options[:counter_sql]
  34             @reflection.klass.count_by_sql(@counter_sql)
  35           else
  36             @reflection.klass.count(:conditions => @counter_sql, :include => @reflection.options[:include])
  37           end
  38
  39           # If there's nothing in the database and @target has no new records
  40           # we are certain the current target is an empty array. This is a
  41           # documented side-effect of the method that may avoid an extra SELECT.
  42           @target ||= [] and loaded if count == 0
  43
  44           if @reflection.options[:limit]
  45             count = [ @reflection.options[:limit], count ].min
  46           end
  47
  48           return count
  49         end
  50
  51         def has_cached_counter?
  52           @owner.attribute_present?(cached_counter_attribute_name)
  53         end
  54
  55         def cached_counter_attribute_name
  56           "#{@reflection.name}_count"
  57         end
  58
  59         def insert_record(record)
  60           set_belongs_to_association_for(record)
  61           record.save
  62         end
  63
  64         # Deletes the records according to the <tt>:dependent</tt> option.
  65         def delete_records(records)
  66           case @reflection.options[:dependent]
  67             when :destroy
  68               records.each { |r| r.destroy }
  69             when :delete_all
  70               @reflection.klass.delete(records.map { |record| record.id })
  71             else
  72               ids = quoted_record_ids(records)
  73               @reflection.klass.update_all(
  74                 "#{@reflection.primary_key_name} = NULL",
  75                 "#{@reflection.primary_key_name} = #{owner_quoted_id} AND #{@reflection.klass.primary_key} IN (#{ids})"
  76               )
  77           end
  78         end
  79
  80         def target_obsolete?
  81           false
  82         end
  83
  84         def construct_sql
  85           case
  86             when @reflection.options[:finder_sql]
  87               @finder_sql = interpolate_sql(@reflection.options[:finder_sql])
  88
  89             when @reflection.options[:as]
  90               @finder_sql =
  91                 "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_id = #{owner_quoted_id} AND " +
  92                 "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote_value(@owner.class.base_class.name.to_s)}"
  93               @finder_sql << " AND (#{conditions})" if conditions
  94
  95             else
  96               @finder_sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"
  97               @finder_sql << " AND (#{conditions})" if conditions
  98           end
  99
 100           if @reflection.options[:counter_sql]
 101             @counter_sql = interpolate_sql(@reflection.options[:counter_sql])
 102           elsif @reflection.options[:finder_sql]
 103             # replace the SELECT clause with COUNT(*), preserving any hints within /* ... */
 104             @reflection.options[:counter_sql] = @reflection.options[:finder_sql].sub(/SELECT (\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }
 105             @counter_sql = interpolate_sql(@reflection.options[:counter_sql])
 106           else
 107             @counter_sql = @finder_sql
 108           end
 109         end
 110
 111         def construct_scope
 112           create_scoping = {}
 113           set_belongs_to_association_for(create_scoping)
 114           {
 115             :find => { :conditions => @finder_sql, :readonly => false, :order => @reflection.options[:order], :limit => @reflection.options[:limit], :include => @reflection.options[:include]},
 116             :create => create_scoping
 117           }
 118         end
 119     end
 120   end
 121 end