Added preliminary support for join models [DHH] Added preliminary support for polymorphic associations [DHH] Refactored associations to use reflections to get DRYer, beware, major refactoring -- double check before deploying anything with this (all tests pass, but..)

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3213 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

1 files changed, 80 insertions, 0 deletions

diff --git a/activerecord/lib/active_record/associations/has_many_through_association.rb b/activerecord/lib/active_record/associations/has_many_through_association.rb
new file mode 100644
index 0000000000..ca4496b32e
--- /dev/null
+++ b/activerecord/lib/active_record/associations/has_many_through_association.rb
@@ -0,0 +1,80 @@
+module ActiveRecord
+  module Associations
+    class HasManyThroughAssociation < AssociationProxy #:nodoc:
+      def find(*args)
+        options = Base.send(:extract_options_from_args!, args)
+
+        conditions = "#{@finder_sql}"
+        if sanitized_conditions = sanitize_sql(options[:conditions])
+          conditions << " AND (#{sanitized_conditions})"
+        end
+        options[:conditions] = conditions
+
+        if options[:order] && @reflection.options[:order]
+          options[:order] = "#{options[:order]}, #{@reflection.options[:order]}"
+        elsif @reflection.options[:order]
+          options[:order] = @reflection.options[:order]
+        end
+
+        # Pass through args exactly as we received them.
+        args << options
+        @reflection.klass.find(*args)
+      end
+
+      def reset
+        @target = []
+        @loaded = false
+      end
+
+      protected
+        def method_missing(method, *args, &block)
+          if @target.respond_to?(method) || (!@reflection.klass.respond_to?(method) && Class.respond_to?(method))
+            super
+          else
+            @reflection.klass.with_scope(construct_scope) { @reflection.klass.send(method, *args, &block) }
+          end
+        end
+            
+        def find_target
+          @reflection.klass.find(:all, 
+            :conditions => construct_conditions,
+            :from       => construct_from,
+            :order      => @reflection.options[:order], 
+            :limit      => @reflection.options[:limit],
+            :joins      => @reflection.options[:joins],
+            :group      => @reflection.options[:group]
+          )
+        end
+
+        def construct_conditions
+          through_reflection = @owner.class.reflections[@reflection.options[:through]]
+          
+          if through_reflection.options[:as]
+            conditions = 
+              "#{@reflection.table_name}.#{@reflection.klass.primary_key} = #{through_reflection.table_name}.#{@reflection.klass.to_s.foreign_key} " +
+              "AND #{through_reflection.table_name}.#{through_reflection.options[:as]}_id = #{@owner.quoted_id} " + 
+              "AND #{through_reflection.table_name}.#{through_reflection.options[:as]}_type = '#{ActiveRecord::Base.send(:class_name_of_active_record_descendant, @owner.class).to_s}'"
+          else
+            conditions = 
+              "#{@reflection.klass.table_name}.#{@reflection.klass.primary_key} = #{through_reflection.table_name}.#{@reflection.klass.to_s.foreign_key} " +
+              "AND #{through_reflection.table_name}.#{@owner.to_s.foreign_key} = #{@owner.quoted_id}"
+          end
+          
+          conditions << " AND (#{interpolate_sql(sanitize_sql(@reflection.options[:conditions]))})" if @reflection.options[:conditions]
+          
+          return conditions
+        end
+
+        def construct_from
+          "#{@reflection.table_name}, #{@owner.class.reflections[@reflection.options[:through]].table_name}"
+        end
+        
+        def construct_scope
+          {
+            :find   => { :conditions => construct_conditions },
+            :create => { @reflection.primary_key_name => @owner.id }
+          }
+        end
+    end
+  end
+end