tests passing against edge rails apart from the ones dependent on rails/rails#399

Author: Ernie Miller

Rakefile

@@ -15,10 +15,9 @@ begin
     gem.homepage = "http://metautonomo.us/projects/metasearch/"
     gem.authors = ["Ernie Miller"]
     gem.add_development_dependency "shoulda"
-    gem.add_dependency "activerecord", "~> 3.0.2"
-    gem.add_dependency "activesupport", "~> 3.0.2"
-    gem.add_dependency "actionpack", "~> 3.0.2"
-    gem.add_dependency "arel", "~> 2.0.2"
+    gem.add_dependency "activerecord", "~> 3.1.0"
+    gem.add_dependency "activesupport", "~> 3.1.0"
+    gem.add_dependency "actionpack", "~> 3.1.0"
     gem.post_install_message = <<END
 
 *** Thanks for installing MetaSearch! ***

VERSION

@@ -1 +1 @@
-1.0.5
+1.1.0.pre

lib/meta_search.rb

@@ -53,7 +53,7 @@ module MetaSearch
 
 I18n.load_path += Dir[File.join(File.dirname(__FILE__), 'meta_search', 'locale', '*.yml')]
 
-ActiveRecord::Associations::ClassMethods::JoinDependency.send(:include, MetaSearch::JoinDependency)
+ActiveRecord::Associations::JoinDependency.send(:include, MetaSearch::JoinDependency)
 ActiveRecord::Base.send(:include, MetaSearch::Searches::ActiveRecord)
 ActionView::Helpers::FormBuilder.send(:include, MetaSearch::Helpers::FormBuilder)
 ActionController::Base.helper(MetaSearch::Helpers::UrlHelper)

lib/meta_search/builder.rb

@@ -35,7 +35,7 @@ def initialize(base_or_relation, opts = {})
       @options = opts  # Let's just hang on to other options for use in authorization blocks
       @join_type = opts[:join_type] ||  Arel::Nodes::OuterJoin
       @join_type = get_join_type(@join_type)
-      @join_dependency = build_join_dependency
+      @join_dependency = build_join_dependency(@relation)
       @search_attributes = {}
       @errors = ActiveModel::Errors.new(self)
     end
@@ -51,12 +51,7 @@ def get_association(assoc, base = @base)
     def get_attribute(name, parent = @join_dependency.join_base)
       attribute = nil
       if get_column(name, parent.active_record)
-        if parent.is_a?(ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation)
-          relation = parent.relation.is_a?(Array) ? parent.relation.last : parent.relation
-          attribute = relation[name]
-        else
-          attribute = @relation.arel_table[name]
-        end
+        attribute = parent.table[name]
       elsif (segments = name.to_s.split(/_/)).size > 1
         remainder = []
         found_assoc = nil
@@ -252,53 +247,58 @@ def type_from_association_segments(segments, base, depth)
       type
     end
 
-    def build_or_find_association(association, parent = @join_dependency.join_base, klass = nil)
+    def build_or_find_association(name, parent = @join_dependency.join_base, klass = nil)
       found_association = @join_dependency.join_associations.detect do |assoc|
-        assoc.reflection.name == association.to_sym &&
-        assoc.reflection.klass == klass &&
-        assoc.parent == parent
+        assoc.reflection.name == name &&
+        assoc.parent == parent &&
+        (!klass || assoc.reflection.klass == klass)
       end
       unless found_association
-        @join_dependency.send(:build_with_metasearch, association, parent, @join_type, klass)
+        @join_dependency.send(:build_polymorphic, name.to_sym, parent, @join_type, klass)
         found_association = @join_dependency.join_associations.last
+        # Leverage the stashed association functionality in AR
         @relation = @relation.joins(found_association)
       end
+
       found_association
     end
 
-    def build_join_dependency
-      joins = @relation.joins_values.map {|j| j.respond_to?(:strip) ? j.strip : j}.uniq
-
-      association_joins = joins.select do |j|
-        [Hash, Array, Symbol].include?(j.class) && !array_of_strings?(j)
-      end
-
-      stashed_association_joins = joins.select do |j|
-        j.is_a?(ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation)
+    def build_join_dependency(relation)
+      buckets = relation.joins_values.group_by do |join|
+        case join
+        when String
+          'string_join'
+        when Hash, Symbol, Array
+          'association_join'
+        when ::ActiveRecord::Associations::JoinDependency::JoinAssociation
+          'stashed_join'
+        when Arel::Nodes::Join
+          'join_node'
+        else
+          raise 'unknown class: %s' % join.class.name
+        end
       end
 
-      non_association_joins = (joins - association_joins - stashed_association_joins)
-      custom_joins = custom_join_sql(*non_association_joins)
+      association_joins         = buckets['association_join'] || []
+      stashed_association_joins = buckets['stashed_join'] || []
+      join_nodes                = buckets['join_node'] || []
+      string_joins              = (buckets['string_join'] || []).map { |x|
+        x.strip
+      }.uniq
 
-      ActiveRecord::Associations::ClassMethods::JoinDependency.new(@base, association_joins, custom_joins)
-    end
+      join_list = relation.send :custom_join_ast, relation.table.from(relation.table), string_joins
 
-    def custom_join_sql(*joins)
-      arel = @relation.table
-      joins.each do |join|
-        next if join.blank?
+      join_dependency = ::ActiveRecord::Associations::JoinDependency.new(
+        relation.klass,
+        association_joins,
+        join_list
+      )
 
-        case join
-        when Hash, Array, Symbol
-          if array_of_strings?(join)
-            join_string = join.join(' ')
-            arel = arel.join(join_string)
-          end
-        else
-          arel = arel.join(join)
-        end
+      join_nodes.each do |join|
+        join_dependency.alias_tracker.aliased_name_for(join.left.name.downcase)
       end
-      arel.joins(arel)
+
+      join_dependency.graft(*stashed_association_joins)
     end
 
     def get_join_type(opt_join)

lib/meta_search/join_dependency.rb

@@ -2,90 +2,93 @@ module MetaSearch
 
   module JoinDependency
 
+    class JoinAssociation < ::ActiveRecord::Associations::JoinDependency::JoinAssociation
+
+      def initialize(reflection, join_dependency, parent = nil, polymorphic_class = nil)
+        if polymorphic_class && ::ActiveRecord::Base > polymorphic_class
+          swapping_reflection_klass(reflection, polymorphic_class) do |reflection|
+            super(reflection, join_dependency, parent)
+          end
+        else
+          super(reflection, join_dependency, parent)
+        end
+      end
+
+      def swapping_reflection_klass(reflection, klass)
+        reflection = reflection.clone
+        original_polymorphic = reflection.options.delete(:polymorphic)
+        reflection.instance_variable_set(:@klass, klass)
+        yield reflection
+      ensure
+        reflection.options[:polymorphic] = original_polymorphic
+      end
+
+      def ==(other)
+        super && active_record == other.active_record
+      end
+
+      def build_constraint(reflection, table, key, foreign_table, foreign_key)
+        if reflection.options[:polymorphic]
+          super.and(
+            foreign_table[reflection.foreign_type].eq(reflection.klass.name)
+          )
+        else
+          super
+        end
+      end
+
+    end
+
+    # Yes, I'm using alias_method_chain here. No, I don't feel too
+    # bad about it. JoinDependency, or, to call it by its full proper
+    # name, ::ActiveRecord::Associations::JoinDependency, is one of the
+    # most "for internal use only" chunks of ActiveRecord.
     def self.included(base)
       base.class_eval do
-        alias_method_chain :graft, :metasearch
+        alias_method_chain :graft, :meta_search
       end
     end
 
-    def graft_with_metasearch(*associations)
+    def graft_with_meta_search(*associations)
       associations.each do |association|
         join_associations.detect {|a| association == a} ||
-        (
-          association.class == MetaSearch::PolymorphicJoinAssociation ?
-          build_with_metasearch(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type, association.reflection.klass) :
-          build(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type)
-        )
+          build_polymorphic(association.reflection.name, association.find_parent_in(self) || join_base, association.join_type, association.reflection.klass)
       end
       self
     end
 
-    protected
+    # Should only be called by MetaSearch, and only with a single association name
+    def build_polymorphic(association, parent = nil, join_type = Arel::OuterJoin, klass = nil)
+      parent ||= join_parts.last
+      reflection = parent.reflections[association] or
+        raise ::ActiveRecord::ConfigurationError, "Association named '#{ association }' was not found; perhaps you misspelled it?"
+      unless join_association = find_join_association_respecting_polymorphism(reflection, parent, klass)
+        @reflections << reflection
+        join_association = build_join_association_respecting_polymorphism(reflection, parent, klass)
+        join_association.join_type = join_type
+        @join_parts << join_association
+        cache_joined_association(join_association)
+      end
 
-      def build_with_metasearch(associations, parent = nil, join_type = Arel::Nodes::InnerJoin, polymorphic_class = nil)
-        parent ||= @joins.last
-        case associations
-        when Symbol, String
-          reflection = parent.reflections[associations.to_s.intern] or
-            raise ConfigurationError, "Association named '#{ associations }' was not found; perhaps you misspelled it?"
-          unless (association = find_join_association(reflection, parent)) && (!polymorphic_class || association.active_record == polymorphic_class)
-            @reflections << reflection
-            if reflection.options[:polymorphic]
-              raise ArgumentError, "You can't create a polymorphic belongs_to join without specifying the polymorphic class!" unless polymorphic_class
-              association = PolymorphicJoinAssociation.new(reflection, self, polymorphic_class, parent)
-            else
-              association = build_join_association(reflection, parent)
-            end
-            association.join_type = join_type
-            @joins << association
-          end
+      join_association
+    end
+
+    def find_join_association_respecting_polymorphism(reflection, parent, klass)
+      if association = find_join_association(reflection, parent)
+        unless reflection.options[:polymorphic]
           association
         else
-          build(associations, parent, join_type)
+          association if association.active_record == klass
         end
       end
-  end
-
-  class PolymorphicJoinAssociation < ActiveRecord::Associations::ClassMethods::JoinDependency::JoinAssociation
-
-    def initialize(reflection, join_dependency, polymorphic_class, parent = nil)
-      reflection.check_validity!
-      @active_record = polymorphic_class
-      @cached_record = {}
-      @join_dependency    = join_dependency
-      @parent             = parent || join_dependency.join_base
-      @reflection         = reflection.clone
-      @reflection.instance_variable_set(:"@klass", polymorphic_class)
-      @aliased_prefix     = "t#{ join_dependency.joins.size }"
-      @parent_table_name  = @parent.active_record.table_name
-      @aliased_table_name = aliased_table_name_for(table_name)
-      @join               = nil
-      @join_type          = Arel::Nodes::InnerJoin
-    end
-
-    def ==(other)
-      other.class == self.class &&
-      other.reflection == reflection &&
-      other.active_record == active_record &&
-      other.parent == parent
     end
 
-    def association_join
-      return @join if @join
-
-      aliased_table = Arel::Table.new(table_name, :as => @aliased_table_name, :engine => arel_engine)
-      parent_table = Arel::Table.new(parent.table_name, :as => parent.aliased_table_name, :engine => arel_engine)
-
-      @join = [
-        aliased_table[options[:primary_key] || reflection.klass.primary_key].eq(parent_table[options[:foreign_key] || reflection.primary_key_name]),
-        parent_table[options[:foreign_type]].eq(active_record.name)
-      ]
-
-      if options[:conditions]
-        @join << interpolate_sql(sanitize_sql(options[:conditions], aliased_table_name))
+    def build_join_association_respecting_polymorphism(reflection, parent, klass = nil)
+      if reflection.options[:polymorphic] && klass
+        JoinAssociation.new(reflection, self, parent, klass)
+      else
+        JoinAssociation.new(reflection, self, parent)
       end
-
-      @join
     end
   end
 end

test/test_view_helpers.rb

@@ -6,18 +6,34 @@ class TestViewHelpers < ActionView::TestCase
   tests MetaSearch::Helpers::FormHelper
   include MetaSearch::Helpers::UrlHelper
 
-  router = ActionDispatch::Routing::RouteSet.new
-  router.draw do
-    resources :developers
-    resources :companies
-    resources :projects
-    resources :notes
-    match ':controller(/:action(/:id(.:format)))'
+  def self.router
+    @router ||= begin
+      router = ActionDispatch::Routing::RouteSet.new
+      router.draw do
+        resources :developers
+        resources :companies
+        resources :projects
+        resources :notes
+        match ':controller(/:action(/:id(.:format)))'
+      end
+      router
+    end
   end
+
   include router.url_helpers
 
+  # FIXME: figure out a cleaner way to get this behavior
   def setup
+    router = self.class.router
     @controller = ActionView::TestCase::TestController.new
+    @controller.instance_variable_set(:@_routes, router)
+    @controller.class_eval do
+      include router.url_helpers
+    end
+
+    @controller.view_context_class.class_eval do
+      include router.url_helpers
+    end
   end
 
   context "A search against Company and a search against Developer" do
@@ -326,7 +342,7 @@ def setup
         end
 
         should "maintain previous search options in its sort links" do
-          assert_match /search\[name_contains\]=a/,
+          assert_match /search%5Bname_contains%5D=a/,
                        sort_link(@s, :name, :controller => 'companies')
         end
       end
@@ -359,7 +375,7 @@ def setup
         end
 
         should "maintain previous search options in its sort links" do
-          assert_match /search\[name_contains\]=a/,
+          assert_match /search%5Bname_contains%5D=a/,
                        sort_link(@s, :company_name, :controller => 'companies')
         end
       end