From dba62c0c95bb299c3c0023b570a7983c3c2c0d16 Mon Sep 17 00:00:00 2001
From: Ken Collins <ken@metaskills.net>
Date: Mon, 5 Dec 2011 14:47:09 -0500
Subject: [PATCH] Final Rails 3.1 notes.

---
 README.md                                     |   5 +-
 .../arish/associations/association_scope.rb   | 102 +++++-------------
 2 files changed, 26 insertions(+), 81 deletions(-)

diff --git a/README.md b/README.md
index d3df717..1f23ea4 100644
--- a/README.md
+++ b/README.md
@@ -82,9 +82,8 @@ defined on the original has_many. For instance:
 
 ## Todo List
 
-* Add polymorphic support.
-* Add :through support.
-* Raise errors and/or support :finder_sql/:counter_sql.
+* Make group association conditions use pure SQL. Avoid many ids.
+* Raise errors for :finder_sql/:counter_sql.
 * Add a user definable group_id schema.
 
 
diff --git a/lib/grouped_scope/arish/associations/association_scope.rb b/lib/grouped_scope/arish/associations/association_scope.rb
index 67feeac..7c1a047 100644
--- a/lib/grouped_scope/arish/associations/association_scope.rb
+++ b/lib/grouped_scope/arish/associations/association_scope.rb
@@ -2,74 +2,81 @@ module GroupedScope
   module Arish
     module Associations
       class AssociationScope < ActiveRecord::Associations::AssociationScope
-
+        
+        
         private
-
+        
+        # A direct copy of of ActiveRecord's AssociationScope#add_constraints. If this was 
+        # in chunks, it would be easier to hook into. This more elegant version which supers
+        # up will only work for the has_many. https://gist.github.com/1434980 
+        # 
+        # We will just have to monitor rails everynow and then and update this. Thankfully this
+        # copy is only used in a group scope. FYI, our one line change is below.
         def add_constraints(scope)
           tables = construct_tables
-
+        
           chain.each_with_index do |reflection, i|
             table, foreign_table = tables.shift, tables.first
-
+        
             if reflection.source_macro == :has_and_belongs_to_many
               join_table = tables.shift
-
+        
               scope = scope.joins(join(
                 join_table,
                 table[reflection.association_primary_key].
                 in(join_table[reflection.association_foreign_key])
               ))
-
+        
               table, foreign_table = join_table, tables.first
             end
-
+        
             if reflection.source_macro == :belongs_to
               if reflection.options[:polymorphic]
                 key = reflection.association_primary_key(klass)
               else
                 key = reflection.association_primary_key
               end
-
+        
               foreign_key = reflection.foreign_key
             else
               key         = reflection.foreign_key
               foreign_key = reflection.active_record_primary_key
             end
-
+        
             conditions = self.conditions[i]
-
+        
             if reflection == chain.last
               # GroupedScope changed this line.
               # scope = scope.where(table[key].eq(owner[foreign_key]))
               scope = scope.where(table[key].in(owner.group.ids))
-
+        
               if reflection.type
                 scope = scope.where(table[reflection.type].eq(owner.class.base_class.name))
               end
-
+        
               conditions.each do |condition|
                 if options[:through] && condition.is_a?(Hash)
                   condition = { table.name => condition }
                 end
-
+        
                 scope = scope.where(interpolate(condition))
               end
             else
               constraint = table[key].eq(foreign_table[foreign_key])
-
+        
               if reflection.type
                 type = chain[i + 1].klass.base_class.name
                 constraint = constraint.and(table[reflection.type].eq(type))
               end
-
+        
               scope = scope.joins(join(foreign_table, constraint))
-
+        
               unless conditions.empty?
                 scope = scope.where(sanitize(conditions, table))
               end
             end
           end
-
+        
           scope
         end
 
@@ -77,64 +84,3 @@ def add_constraints(scope)
     end
   end
 end
-
-=begin
-
-# Initial #add_constraints Idea
-# -----------------------------
-
-super(scope).tap do |s|
-  case reflection.macro
-  when :has_many
-    ...
-  end if reflection.grouped_scope?
-end
-
-
-# Simple AssociationScope Methods
-# -------------------------------
-
-as = ActiveRecord::Associations::AssociationScope.new(User.first.association(:columns)) ; as.object_id
-as.klass          # => Column(3 columns)
-as.owner          # => #<User id: 8, ...>
-as.active_record  # => User(14 columns)
-
-
-# Reflection Stuff For Join Through
-# ---------------------------------
-
-as.reflection
-# => #<ActiveRecord::Reflection::AssociationReflection:0x007fdcd890bd18 @macro=:has_many, @name=:columns, @options={:order=>"position", :extend=>[]}, @active_record=User(14 columns), @plural_name="columns", @collection=true, @class_name="Column", @klass=Column(3 columns), @foreign_key="user_id", @active_record_primary_key="id", @type=nil>
-
-as.reflection.association_primary_key # => "id"
-as.reflection.association_foreign_key # => "column_id"
-
-
-# How Tables Work In #add_constraints
-# -----------------------------------
-
-tables = as.send(:construct_tables)
-table = tables.first
-
-key = as.reflection.foreign_key                         # => "user_id"
-foreign_key = as.reflection.active_record_primary_key   # => "id"
-
-table[key].eq(as.owner[foreign_key]).to_sql             # => "columns"."user_id" = 8
-table[key].in([1,2,3]).to_sql                           # => "columns"."user_id" IN (1, 2, 3)
-table[key].in(as.owner.group.ids).to_sql                # => 
-
-
-
-
-
-s = as.scope ; s.object_id
-equalities = s.where_values.grep(Arel::Nodes::Equality)
-
-e = equalities.first
-# => #<Arel::Nodes::Equality:0x007fdcd8546ed0 @left=#<struct Arel::Attributes::Attribute relation=#<Arel::Table:0x007fdcd85471a0 @name="columns", @engine=ActiveRecord::Base, @columns=nil, @aliases=[], @table_alias=nil, @primary_key=nil>, name="user_id">, @right=8>
-
-
-
-
-
-=end