made .find() and class method delegation work on :through relations

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@3325 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

activerecord/CHANGELOG

 *SVN*
 
+* made method missing delegation to class methods on relation target work on :through associations. [Tobias Luetke]
+
+* made .find() work on :through relations. [Tobias Luetke]
+
 * added :piggyback option to has_many :through relationships to pick up values from the join table as needed [Tobias Luetke] 
 
 * Fix typo in association docs. #3296. [Blair Zajac]

activerecord/lib/active_record/associations/has_many_through_association.rb

 module ActiveRecord
   module Associations
     class HasManyThroughAssociation < AssociationProxy #:nodoc:
+
+      def initialize(owner, reflection)
+        super
+        @finder_sql = construct_conditions
+        construct_sql
+      end
+
+
       def find(*args)
         options = Base.send(:extract_options_from_args!, args)
 
@@ -15,7 +23,10 @@ def find(*args)
         elsif @reflection.options[:order]
           options[:order] = @reflection.options[:order]
         end
-
+        
+        options[:select] = construct_select
+        options[:from]   = construct_from
+        
         merge_options_from_reflection!(options)
 
         # Pass through args exactly as we received them.
@@ -83,10 +94,30 @@ def construct_select
         
         def construct_scope
           {
-            :find   => { :conditions => construct_conditions },
+            :find   => { :from => construct_from, :conditions => construct_conditions },
             :create => { @reflection.primary_key_name => @owner.id }
           }
         end
+        
+        def construct_sql
+          case
+            when @reflection.options[:finder_sql]
+              @finder_sql = interpolate_sql(@reflection.options[:finder_sql])
+
+              @finder_sql = "#{@reflection.klass.table_name}.#{@reflection.primary_key_name} = #{@owner.quoted_id}"
+              @finder_sql << " AND (#{interpolate_sql(@conditions)})" if @conditions
+          end
+
+          if @reflection.options[:counter_sql]
+            @counter_sql = interpolate_sql(@reflection.options[:counter_sql])
+          elsif @reflection.options[:finder_sql]
+            @reflection.options[:counter_sql] = @reflection.options[:finder_sql].gsub(/SELECT (.*) FROM/i, "SELECT COUNT(*) FROM")
+            @counter_sql = interpolate_sql(@reflection.options[:counter_sql])
+          else
+            @counter_sql = @finder_sql
+          end
+        end
+        
     end
   end
 end

activerecord/lib/active_record/base.rb

@@ -853,7 +853,7 @@ def with_scope(method_scoping = {})
 
         method_scoping.assert_valid_keys [:find, :create]
         if f = method_scoping[:find]
-          f.assert_valid_keys [:conditions, :joins, :offset, :limit, :readonly]
+          f.assert_valid_keys [:conditions, :joins, :from, :offset, :limit, :readonly]
           f[:readonly] = true if !f[:joins].blank? && !f.has_key?(:readonly)
         end
 
@@ -917,7 +917,7 @@ def type_name_with_module(type_name)
 
         def construct_finder_sql(options)
           sql  = "SELECT #{options[:select] || '*'} "
-          sql << "FROM #{options[:from] || table_name} "
+          sql << "FROM #{scope(:find, :from) || options[:from] || table_name} "
 
           add_joins!(sql, options)
           add_conditions!(sql, options[:conditions])

activerecord/test/associations_join_model_test.rb

@@ -42,5 +42,23 @@ def test_polymorphic_has_many_going_through_join_model_with_inheritance
   def test_has_many_with_piggyback
     assert_equal "2", categories(:sti_test).authors.first.post_id
   end
+  
+  def test_has_many_find_all
+    assert_equal [categories(:general)], authors(:david).categories.find(:all)
+  end
+  
+  def test_has_many_find_first
+    assert_equal categories(:general), authors(:david).categories.find(:first)
+  end
+  
+  def test_has_many_find_conditions
+    assert_equal categories(:general), authors(:david).categories.find(:first, :conditions => "categories.name = 'General'")
+    assert_equal nil, authors(:david).categories.find(:first, :conditions => "categories.name = 'Technology'")
+  end
+  
+  def test_has_many_class_methods_called_by_method_missing
+    assert_equal categories(:general), authors(:david).categories.find_by_name('General')
+#    assert_equal nil, authors(:david).categories.find_by_name('Technology')
+  end
     
 end