~michaelforrest/use-case-mapper/trunk

module ActiveRecord

  module Associations

    # This is the proxy that handles a has many association.

    #

    # If the association has a <tt>:through</tt> option further specialization

    # is provided by its child HasManyThroughAssociation.

    class HasManyAssociation < AssociationCollection #:nodoc:

      protected

        def owner_quoted_id

          if @reflection.options[:primary_key]

            quote_value(@owner.send(@reflection.options[:primary_key]))

          else

            @owner.quoted_id

          end

        end

 

        # Returns the number of records in this collection.

        #

        # If the association has a counter cache it gets that value. Otherwise

        # it will attempt to do a count via SQL, bounded to <tt>:limit</tt> if

        # there's one.  Some configuration options like :group make it impossible

        # to do a SQL count, in those cases the array count will be used.

        #

        # That does not depend on whether the collection has already been loaded

        # or not. The +size+ method is the one that takes the loaded flag into

        # account and delegates to +count_records+ if needed.

        #

        # If the collection is empty the target is set to an empty array and

        # the loaded flag is set to true as well.

        def count_records

          count = if has_cached_counter?

            @owner.send(:read_attribute, cached_counter_attribute_name)

          elsif @reflection.options[:counter_sql]

            @reflection.klass.count_by_sql(@counter_sql)

          else

            @reflection.klass.count(:conditions => @counter_sql, :include => @reflection.options[:include])

          end

 

          # If there's nothing in the database and @target has no new records

          # we are certain the current target is an empty array. This is a

          # documented side-effect of the method that may avoid an extra SELECT.

          @target ||= [] and loaded if count == 0

          

          if @reflection.options[:limit]

            count = [ @reflection.options[:limit], count ].min

          end

          

          return count

        end

 

        def has_cached_counter?

          @owner.attribute_present?(cached_counter_attribute_name)

        end

 

        def cached_counter_attribute_name

          "#{@reflection.name}_count"

        end

 

        def insert_record(record, force = false, validate = true)

          set_belongs_to_association_for(record)

          force ? record.save! : record.save(validate)

        end

 

        # Deletes the records according to the <tt>:dependent</tt> option.

        def delete_records(records)

          case @reflection.options[:dependent]

            when :destroy

              records.each { |r| r.destroy }

            when :delete_all

              @reflection.klass.delete(records.map { |record| record.id })

            else

              ids = quoted_record_ids(records)

              @reflection.klass.update_all(

                "#{@reflection.primary_key_name} = NULL", 

                "#{@reflection.primary_key_name} = #{owner_quoted_id} AND #{@reflection.klass.primary_key} IN (#{ids})"

              )

              @owner.class.update_counters(@owner.id, cached_counter_attribute_name => -records.size) if has_cached_counter?

          end

        end

 

        def target_obsolete?

          false

        end

 

        def construct_sql

          case

            when @reflection.options[:finder_sql]

              @finder_sql = interpolate_sql(@reflection.options[:finder_sql])

 

            when @reflection.options[:as]

              @finder_sql = 

                "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_id = #{owner_quoted_id} AND " +

                "#{@reflection.quoted_table_name}.#{@reflection.options[:as]}_type = #{@owner.class.quote_value(@owner.class.base_class.name.to_s)}"

              @finder_sql << " AND (#{conditions})" if conditions

            

            else

              @finder_sql = "#{@reflection.quoted_table_name}.#{@reflection.primary_key_name} = #{owner_quoted_id}"

              @finder_sql << " AND (#{conditions})" if conditions

          end

 

          if @reflection.options[:counter_sql]

            @counter_sql = interpolate_sql(@reflection.options[:counter_sql])

          elsif @reflection.options[:finder_sql]

            # replace the SELECT clause with COUNT(*), preserving any hints within /* ... */

            @reflection.options[:counter_sql] = @reflection.options[:finder_sql].sub(/SELECT (\/\*.*?\*\/ )?(.*)\bFROM\b/im) { "SELECT #{$1}COUNT(*) FROM" }

            @counter_sql = interpolate_sql(@reflection.options[:counter_sql])

          else

            @counter_sql = @finder_sql

          end

        end

 

        def construct_scope

          create_scoping = {}

          set_belongs_to_association_for(create_scoping)

          {

            :find => { :conditions => @finder_sql, :readonly => false, :order => @reflection.options[:order], :limit => @reflection.options[:limit], :include => @reflection.options[:include]},

            :create => create_scoping

          }

        end

    end

  end

end