From 235eae3b825e16a6a02e37423b2d24f6cda97da5 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Sat, 2 Jan 2016 10:27:52 -0800
Subject: [PATCH 01/11] Refactor: condition handles binding of its attribute

---
 .../adapters/active_record/ransack/context.rb     |  2 +-
 lib/ransack/context.rb                            |  1 +
 lib/ransack/nodes/attribute.rb                    |  1 -
 lib/ransack/nodes/condition.rb                    | 15 +++++++--------
 lib/ransack/nodes/sort.rb                         |  2 +-
 5 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/lib/ransack/adapters/active_record/ransack/context.rb b/lib/ransack/adapters/active_record/ransack/context.rb
index eba9539ab..12d75aead 100644
--- a/lib/ransack/adapters/active_record/ransack/context.rb
+++ b/lib/ransack/adapters/active_record/ransack/context.rb
@@ -40,7 +40,7 @@ def initialize(object, options = {})
         @base.table_name, as: @base.aliased_table_name, type_caster: self
         )
       @bind_pairs = Hash.new do |hash, key|
-        parent, attr_name = get_parent_and_attribute_name(key.to_s)
+        parent, attr_name = get_parent_and_attribute_name(key)
         if parent && attr_name
           hash[key] = [parent, attr_name]
         end
diff --git a/lib/ransack/context.rb b/lib/ransack/context.rb
index 8be64d627..5f012bfba 100644
--- a/lib/ransack/context.rb
+++ b/lib/ransack/context.rb
@@ -58,6 +58,7 @@ def scope_arity(scope)
     end
 
     def bind(object, str)
+      return nil unless str
       object.parent, object.attr_name = @bind_pairs[str]
     end
 
diff --git a/lib/ransack/nodes/attribute.rb b/lib/ransack/nodes/attribute.rb
index 0b2fc3b1f..3183a3dd0 100644
--- a/lib/ransack/nodes/attribute.rb
+++ b/lib/ransack/nodes/attribute.rb
@@ -16,7 +16,6 @@ def initialize(context, name = nil, ransacker_args = [])
 
       def name=(name)
         @name = name
-        context.bind(self, name) unless name.blank?
       end
 
       def valid?
diff --git a/lib/ransack/nodes/condition.rb b/lib/ransack/nodes/condition.rb
index 5bd3982af..ab09ecf4a 100644
--- a/lib/ransack/nodes/condition.rb
+++ b/lib/ransack/nodes/condition.rb
@@ -79,14 +79,12 @@ def attributes
       def attributes=(args)
         case args
         when Array
-          args.each do |attr|
-            attr = Attribute.new(@context, attr)
-            self.attributes << attr if attr.valid?
+          args.each do |name|
+            build_attribute(name)
           end
         when Hash
           args.each do |index, attrs|
-            attr = Attribute.new(@context, attrs[:name], attrs[:ransacker_args])
-            self.attributes << attr if attr.valid?
+            build_attribute(attrs[:name], attrs[:ransacker_args])
           end
         else
           raise ArgumentError,
@@ -129,9 +127,10 @@ def combinator=(val)
       alias :m= :combinator=
       alias :m :combinator
 
-      def build_attribute(name = nil)
-        Attribute.new(@context, name).tap do |attribute|
-          self.attributes << attribute
+      def build_attribute(name = nil, ransacker_args = [])
+        Attribute.new(@context, name, ransacker_args).tap do |attribute|
+          @context.bind(attribute, attribute.name)
+          self.attributes << attribute if attribute.valid?
         end
       end
 
diff --git a/lib/ransack/nodes/sort.rb b/lib/ransack/nodes/sort.rb
index 0a700df86..244aeec74 100644
--- a/lib/ransack/nodes/sort.rb
+++ b/lib/ransack/nodes/sort.rb
@@ -32,7 +32,7 @@ def valid?
 
       def name=(name)
         @name = name
-        context.bind(self, name) unless name.blank?
+        context.bind(self, name)
       end
 
       def dir=(dir)

From 3df134e08e798d077155e24005138d4b6d1bdfd5 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Sat, 2 Jan 2016 10:49:13 -0800
Subject: [PATCH 02/11] Tell if a condition is negative

---
 lib/ransack/nodes/condition.rb       | 4 ++++
 lib/ransack/predicate.rb             | 4 ++++
 spec/ransack/nodes/condition_spec.rb | 9 +++++++++
 3 files changed, 17 insertions(+)

diff --git a/lib/ransack/nodes/condition.rb b/lib/ransack/nodes/condition.rb
index ab09ecf4a..1fe3f288c 100644
--- a/lib/ransack/nodes/condition.rb
+++ b/lib/ransack/nodes/condition.rb
@@ -247,6 +247,10 @@ def inspect
         "Condition <#{data}>"
       end
 
+      def negative?
+        predicate.negative?
+      end
+
       private
 
       def valid_combinator?
diff --git a/lib/ransack/predicate.rb b/lib/ransack/predicate.rb
index 2b5bd5da5..935729469 100644
--- a/lib/ransack/predicate.rb
+++ b/lib/ransack/predicate.rb
@@ -74,5 +74,9 @@ def validate(vals, type = @type)
       vals.any? { |v| validator.call(type ? v.cast(type) : v.value) }
     end
 
+    def negative?
+      @name.include?("not_".freeze)
+    end
+
   end
 end
diff --git a/spec/ransack/nodes/condition_spec.rb b/spec/ransack/nodes/condition_spec.rb
index 6cb728ddc..8520fd882 100644
--- a/spec/ransack/nodes/condition_spec.rb
+++ b/spec/ransack/nodes/condition_spec.rb
@@ -29,6 +29,15 @@ module Nodes
         specify { expect(subject.values.size).to eq(2) }
       end
 
+      describe '#negative?' do
+        let(:context) { Context.for(Person) }
+        let(:eq)      { Condition.extract(context, 'name_eq', 'A') }
+        let(:not_eq)  { Condition.extract(context, 'name_not_eq', 'A') }
+
+        specify { expect(not_eq.negative?).to be true }
+        specify { expect(eq.negative?).to be false }
+      end
+
       context 'with an invalid predicate' do
         subject {
           Condition.extract(

From 17742fd0bf952e01be7345bf7105afd61082e5e0 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Fri, 8 Jan 2016 15:31:54 -0800
Subject: [PATCH 03/11] Refactor build_or_find_association into separate
 methods

---
 lib/ransack/adapters/active_record/context.rb | 72 ++++++++++---------
 1 file changed, 39 insertions(+), 33 deletions(-)

diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 4f68d6502..3eb03160f 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -242,37 +242,41 @@ def convert_join_strings_to_ast(table, joins)
           .map { |join| table.create_string_join(Arel.sql(join)) }
         end
 
+        def build_or_find_association(name, parent = @base, klass = nil)
+          find_association(name, parent, klass) or build_association(name, parent, klass)
+        end
+
         if ::ActiveRecord::VERSION::STRING >= Constants::RAILS_4_1
 
-          def build_or_find_association(name, parent = @base, klass = nil)
-            found_association = @join_dependency.join_root.children
-            .detect do |assoc|
+          def find_association(name, parent = @base, klass = nil)
+            @join_dependency.join_root.children.detect do |assoc|
               assoc.reflection.name == name &&
               (@associations_pot.nil? || @associations_pot[assoc] == parent) &&
               (!klass || assoc.reflection.klass == klass)
             end
+          end
 
-            unless found_association
-              jd = JoinDependency.new(
-                parent.base_klass,
-                Polyamorous::Join.new(name, @join_type, klass),
-                []
+          def build_association(name, parent = @base, klass = nil)
+            jd = JoinDependency.new(
+              parent.base_klass,
+              Polyamorous::Join.new(name, @join_type, klass),
+              []
+            )
+            found_association = jd.join_root.children.last
+            associations found_association, parent
+
+            # TODO maybe we dont need to push associations here, we could loop
+            # through the @associations_pot instead
+            @join_dependency.join_root.children.push found_association
+
+            # Builds the arel nodes properly for this association
+            @join_dependency.send(
+              :construct_tables!, jd.join_root, found_association
               )
-              found_association = jd.join_root.children.last
-              associations found_association, parent
 
-              # TODO maybe we dont need to push associations here, we could loop
-              # through the @associations_pot instead
-              @join_dependency.join_root.children.push found_association
+            # Leverage the stashed association functionality in AR
+            @object = @object.joins(jd)
 
-              # Builds the arel nodes properly for this association
-              @join_dependency.send(
-                :construct_tables!, jd.join_root, found_association
-                )
-
-              # Leverage the stashed association functionality in AR
-              @object = @object.joins(jd)
-            end
             found_association
           end
 
@@ -283,24 +287,26 @@ def associations(assoc, parent)
 
         else
 
-          def build_or_find_association(name, parent = @base, klass = nil)
+          def build_association(name, parent = @base, klass = nil)
+            @join_dependency.send(
+              :build,
+              Polyamorous::Join.new(name, @join_type, klass),
+              parent
+              )
+            found_association = @join_dependency.join_associations.last
+            # Leverage the stashed association functionality in AR
+            @object = @object.joins(found_association)
+
+            found_association
+          end
+
+          def find_association(name, parent = @base, klass = nil)
             found_association = @join_dependency.join_associations
             .detect do |assoc|
               assoc.reflection.name == name &&
               assoc.parent == parent &&
               (!klass || assoc.reflection.klass == klass)
             end
-            unless found_association
-              @join_dependency.send(
-                :build,
-                Polyamorous::Join.new(name, @join_type, klass),
-                parent
-                )
-              found_association = @join_dependency.join_associations.last
-              # Leverage the stashed association functionality in AR
-              @object = @object.joins(found_association)
-            end
-            found_association
           end
 
         end

From 4b1544898cc2f4d15b69f964f09ececa71fd6e92 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Fri, 8 Jan 2016 16:43:14 -0800
Subject: [PATCH 04/11] Clean out unused constant references

---
 lib/ransack/adapters/active_record/3.1/context.rb | 1 -
 lib/ransack/adapters/active_record/context.rb     | 1 -
 lib/ransack/adapters/mongoid/context.rb           | 4 ----
 3 files changed, 6 deletions(-)

diff --git a/lib/ransack/adapters/active_record/3.1/context.rb b/lib/ransack/adapters/active_record/3.1/context.rb
index 2a718d2e8..e736bb493 100644
--- a/lib/ransack/adapters/active_record/3.1/context.rb
+++ b/lib/ransack/adapters/active_record/3.1/context.rb
@@ -8,7 +8,6 @@ module ActiveRecord
       class Context < ::Ransack::Context
         # Because the AR::Associations namespace is insane
         JoinDependency = ::ActiveRecord::Associations::JoinDependency
-        JoinPart = JoinDependency::JoinPart
 
         # Redefine a few things for ActiveRecord 3.1.
 
diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 3eb03160f..4e10f3dfc 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -9,7 +9,6 @@ class Context < ::Ransack::Context
 
         # Because the AR::Associations namespace is insane
         JoinDependency = ::ActiveRecord::Associations::JoinDependency
-        JoinPart = JoinDependency::JoinPart
 
         def initialize(object, options = {})
           super
diff --git a/lib/ransack/adapters/mongoid/context.rb b/lib/ransack/adapters/mongoid/context.rb
index 1847f5d84..b36b24461 100644
--- a/lib/ransack/adapters/mongoid/context.rb
+++ b/lib/ransack/adapters/mongoid/context.rb
@@ -6,10 +6,6 @@ module Adapters
     module Mongoid
       class Context < ::Ransack::Context
 
-        # Because the AR::Associations namespace is insane
-        # JoinDependency = ::Mongoid::Associations::JoinDependency
-        # JoinPart = JoinDependency::JoinPart
-
         def initialize(object, options = {})
           super
           # @arel_visitor = @engine.connection.visitor

From 00631f969d615ccf48f89cf33dadd841780100b3 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Thu, 11 Feb 2016 18:26:11 -0800
Subject: [PATCH 05/11] Refactor: inline private method

---
 .../active_record/ransack/nodes/condition.rb       | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)

diff --git a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
index a45eba7f0..da39c5f4b 100644
--- a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
+++ b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
@@ -3,7 +3,11 @@ module Nodes
     class Condition
 
       def arel_predicate
-        arel_predicate_for(attributes_array)
+        if attributes.size > 1
+          combinator_for(attributes_array)
+        else
+          format_predicate(attributes_array.first)
+        end
       end
 
       private
@@ -16,14 +20,6 @@ def attributes_array
           end
         end
 
-        def arel_predicate_for(predicates)
-          if predicates.size > 1
-            combinator_for(predicates)
-          else
-            format_predicate(predicates.first)
-          end
-        end
-
         def combinator_for(predicates)
           if combinator === Constants::AND
             Arel::Nodes::Grouping.new(Arel::Nodes::And.new(predicates))

From 55e56acd0adb613545e453d85a064aae0f955693 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Thu, 11 Feb 2016 18:29:24 -0800
Subject: [PATCH 06/11] Confusing private arguments and method names

---
 .../active_record/ransack/nodes/condition.rb  | 22 +++++++++----------
 1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
index da39c5f4b..b248bd315 100644
--- a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
+++ b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
@@ -4,15 +4,15 @@ class Condition
 
       def arel_predicate
         if attributes.size > 1
-          combinator_for(attributes_array)
+          combinator_for_predicates
         else
-          format_predicate(attributes_array.first)
+          format_predicate
         end
       end
 
       private
 
-        def attributes_array
+        def arel_predicates
           attributes.map do |a|
             a.attr.send(
               arel_predicate_for_attribute(a), formatted_values_for_attribute(a)
@@ -20,20 +20,20 @@ def attributes_array
           end
         end
 
-        def combinator_for(predicates)
+        def combinator_for_predicates
           if combinator === Constants::AND
-            Arel::Nodes::Grouping.new(Arel::Nodes::And.new(predicates))
+            Arel::Nodes::Grouping.new(arel_predicates.inject(&:and))
           elsif combinator === Constants::OR
-            predicates.inject(&:or)
+            arel_predicates.inject(&:or)
           end
         end
 
-        def format_predicate(predicate)
-          predicate.tap do
-            if casted_array_with_in_predicate?(predicate)
-              predicate.right[0] = format_values_for(predicate.right[0])
-            end
+        def format_predicate
+          predicate = arel_predicates.first
+          if casted_array_with_in_predicate?(predicate)
+            predicate.right[0] = format_values_for(predicate.right[0])
           end
+          predicate
         end
 
         def casted_array_with_in_predicate?(predicate)

From a873c63db0e762ad9c744cf9d5d7916b5a7d4caf Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Fri, 12 Feb 2016 15:13:45 -0800
Subject: [PATCH 07/11] Load older versions as overrides to share logic

---
 lib/ransack/adapters/active_record.rb             | 4 ++--
 lib/ransack/adapters/active_record/3.0/context.rb | 6 ++++--
 lib/ransack/adapters/active_record/3.1/context.rb | 2 --
 lib/ransack/adapters/active_record/context.rb     | 4 +++-
 4 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/lib/ransack/adapters/active_record.rb b/lib/ransack/adapters/active_record.rb
index 1a4369d59..0ffbf303c 100644
--- a/lib/ransack/adapters/active_record.rb
+++ b/lib/ransack/adapters/active_record.rb
@@ -1,6 +1,8 @@
 require 'ransack/adapters/active_record/base'
 ActiveRecord::Base.extend Ransack::Adapters::ActiveRecord::Base
 
+require 'ransack/adapters/active_record/context'
+
 case ActiveRecord::VERSION::STRING
 when /^3\.0\./
   require 'ransack/adapters/active_record/3.0/context'
@@ -8,6 +10,4 @@
   require 'ransack/adapters/active_record/3.1/context'
 when /^3\.2\./
   require 'ransack/adapters/active_record/3.2/context'
-else
-  require 'ransack/adapters/active_record/context'
 end
diff --git a/lib/ransack/adapters/active_record/3.0/context.rb b/lib/ransack/adapters/active_record/3.0/context.rb
index f9ad0f726..e725a2cdf 100644
--- a/lib/ransack/adapters/active_record/3.0/context.rb
+++ b/lib/ransack/adapters/active_record/3.0/context.rb
@@ -7,9 +7,11 @@ module Ransack
   module Adapters
     module ActiveRecord
       class Context < ::Ransack::Context
+
         # Because the AR::Associations namespace is insane
-        JoinDependency = ::ActiveRecord::Associations::ClassMethods::JoinDependency
-        JoinBase = JoinDependency::JoinBase
+        if defined? ::ActiveRecord::Associations::ClassMethods::JoinDependency
+          JoinDependency = ::ActiveRecord::Associations::ClassMethods::JoinDependency
+        end
 
         # Redefine a few things for ActiveRecord 3.0.
 
diff --git a/lib/ransack/adapters/active_record/3.1/context.rb b/lib/ransack/adapters/active_record/3.1/context.rb
index e736bb493..8a9cbdc07 100644
--- a/lib/ransack/adapters/active_record/3.1/context.rb
+++ b/lib/ransack/adapters/active_record/3.1/context.rb
@@ -6,8 +6,6 @@ module Ransack
   module Adapters
     module ActiveRecord
       class Context < ::Ransack::Context
-        # Because the AR::Associations namespace is insane
-        JoinDependency = ::ActiveRecord::Associations::JoinDependency
 
         # Redefine a few things for ActiveRecord 3.1.
 
diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 4e10f3dfc..381a69c81 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -8,7 +8,9 @@ module ActiveRecord
       class Context < ::Ransack::Context
 
         # Because the AR::Associations namespace is insane
-        JoinDependency = ::ActiveRecord::Associations::JoinDependency
+        if defined? ::ActiveRecord::Associations::JoinDependency
+          JoinDependency = ::ActiveRecord::Associations::JoinDependency
+        end
 
         def initialize(object, options = {})
           super

From 43cf9ec33ebbf38c580cf9f5bff0c3f211811a8b Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Tue, 16 Feb 2016 01:02:18 -0800
Subject: [PATCH 08/11] Inline internal method

---
 lib/ransack/adapters/active_record/context.rb | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index 381a69c81..f1b0a3bf2 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -15,6 +15,7 @@ class Context < ::Ransack::Context
         def initialize(object, options = {})
           super
           @arel_visitor = @engine.connection.visitor
+          @associations_pot = {}
         end
 
         def relation_for(object)
@@ -252,7 +253,7 @@ def build_or_find_association(name, parent = @base, klass = nil)
           def find_association(name, parent = @base, klass = nil)
             @join_dependency.join_root.children.detect do |assoc|
               assoc.reflection.name == name &&
-              (@associations_pot.nil? || @associations_pot[assoc] == parent) &&
+              (@associations_pot.empty? || @associations_pot[assoc] == parent) &&
               (!klass || assoc.reflection.klass == klass)
             end
           end
@@ -264,7 +265,7 @@ def build_association(name, parent = @base, klass = nil)
               []
             )
             found_association = jd.join_root.children.last
-            associations found_association, parent
+            @associations_pot[found_association] = parent
 
             # TODO maybe we dont need to push associations here, we could loop
             # through the @associations_pot instead
@@ -281,11 +282,6 @@ def build_association(name, parent = @base, klass = nil)
             found_association
           end
 
-          def associations(assoc, parent)
-            @associations_pot ||= {}
-            @associations_pot[assoc] = parent
-          end
-
         else
 
           def build_association(name, parent = @base, klass = nil)

From eb8257092a60dc64ef391de1347eed0284d1651a Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Mon, 15 Feb 2016 11:02:09 -0800
Subject: [PATCH 09/11] Silence deprecation warning

---
 spec/ransack/helpers/form_helper_spec.rb | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/spec/ransack/helpers/form_helper_spec.rb b/spec/ransack/helpers/form_helper_spec.rb
index 7dc28d112..c0af3a0cb 100644
--- a/spec/ransack/helpers/form_helper_spec.rb
+++ b/spec/ransack/helpers/form_helper_spec.rb
@@ -312,7 +312,7 @@ module Helpers
 
       context 'view has existing parameters' do
         before do
-          @controller.view_context.params.merge!({ exist: 'existing' })
+          @controller.view_context.params[:exist] = 'existing'
         end
         describe '#sort_link should not remove existing params' do
           subject { @controller.view_context

From 96d0fd75ade6a6ca019ccc03cca6d876f0e12ecf Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Fri, 8 Jan 2016 16:18:24 -0800
Subject: [PATCH 10/11] Query for negative associations as subquery

When a collection association (has_many, etc) is searched for negative
conditions (NOT...), a JOIN will still include other rows that match.

The implied meaning is that it should only select where *none* of the
associations match, but the actual result still selects records where
*any* of the joined associations match.

This implementation removes joins that were added while building the
conditions and moves them into a subquery if needed.
---
 lib/ransack/adapters/active_record/context.rb | 79 ++++++++++++++++++-
 .../adapters/active_record/ransack/context.rb |  2 +
 .../active_record/ransack/nodes/condition.rb  | 38 ++++-----
 lib/ransack/nodes/attribute.rb                |  4 +
 lib/ransack/nodes/condition.rb                |  7 ++
 .../adapters/active_record/base_spec.rb       | 70 ++++++++++++++++
 6 files changed, 178 insertions(+), 22 deletions(-)

diff --git a/lib/ransack/adapters/active_record/context.rb b/lib/ransack/adapters/active_record/context.rb
index f1b0a3bf2..390664a4d 100644
--- a/lib/ransack/adapters/active_record/context.rb
+++ b/lib/ransack/adapters/active_record/context.rb
@@ -15,7 +15,6 @@ class Context < ::Ransack::Context
         def initialize(object, options = {})
           super
           @arel_visitor = @engine.connection.visitor
-          @associations_pot = {}
         end
 
         def relation_for(object)
@@ -139,6 +138,64 @@ def alias_tracker
           @join_dependency.alias_tracker
         end
 
+        def lock_association(association)
+          @lock_associations << association
+        end
+
+        if ::ActiveRecord::VERSION::STRING >= Constants::RAILS_4_1
+          def remove_association(association)
+            return if @lock_associations.include?(association)
+            @join_dependency.join_root.children.delete_if { |stashed|
+              stashed.eql?(association)
+            }
+            @object.joins_values.delete_if { |jd|
+              jd.join_root.children.map(&:object_id) == [association.object_id]
+            }
+          end
+        else
+          def remove_association(association)
+            return if @lock_associations.include?(association)
+            @join_dependency.join_parts.delete(association)
+            @object.joins_values.delete(association)
+          end
+        end
+
+        # Build an Arel subquery that selects keys for the top query,
+        # drawn from the first join association's foreign_key.
+        #
+        # Example: for an Article that has_and_belongs_to_many Tags
+        #
+        #   context = Article.search.context
+        #   attribute = Attribute.new(context, "tags_name").tap do |a|
+        #     context.bind(a, a.name)
+        #   end
+        #   context.build_correlated_subquery(attribute.parent).to_sql
+        #
+        #   # SELECT "articles_tags"."article_id" FROM "articles_tags"
+        #   # INNER JOIN "tags" ON "tags"."id" = "articles_tags"."tag_id"
+        #   # WHERE "articles_tags"."article_id" = "articles"."id"
+        #
+        # The WHERE condition on this query makes it invalid by itself,
+        # because it is correlated to the primary key on the outer query.
+        #
+        def build_correlated_subquery(association)
+          join_constraints = extract_joins(association)
+          join_root = join_constraints.shift
+          join_table = join_root.left
+          correlated_key = join_root.right.expr.left
+          subquery = Arel::SelectManager.new(association.base_klass)
+          subquery.from(join_root.left)
+          subquery.project(correlated_key)
+          join_constraints.each do |j|
+            subquery.join_sources << Arel::Nodes::InnerJoin.new(j.left, j.right)
+          end
+          subquery.where(correlated_key.eq(primary_key))
+        end
+
+        def primary_key
+          @object.table[@object.primary_key]
+        end
+
         private
 
         def database_table_exists?
@@ -282,6 +339,21 @@ def build_association(name, parent = @base, klass = nil)
             found_association
           end
 
+          def extract_joins(association)
+            parent = @join_dependency.join_root
+            reflection = association.reflection
+            join_constraints = association.join_constraints(
+              parent.table,
+              parent.base_klass,
+              association,
+              Arel::Nodes::OuterJoin,
+              association.tables,
+              reflection.scope_chain,
+              reflection.chain
+            )
+            join_constraints.to_a.flatten
+          end
+
         else
 
           def build_association(name, parent = @base, klass = nil)
@@ -297,6 +369,11 @@ def build_association(name, parent = @base, klass = nil)
             found_association
           end
 
+          def extract_joins(association)
+            query = Arel::SelectManager.new(association.base_klass, association.table)
+            association.join_to(query).join_sources
+          end
+
           def find_association(name, parent = @base, klass = nil)
             found_association = @join_dependency.join_associations
             .detect do |assoc|
diff --git a/lib/ransack/adapters/active_record/ransack/context.rb b/lib/ransack/adapters/active_record/ransack/context.rb
index 12d75aead..708efeaa2 100644
--- a/lib/ransack/adapters/active_record/ransack/context.rb
+++ b/lib/ransack/adapters/active_record/ransack/context.rb
@@ -27,6 +27,8 @@ def initialize(object, options = {})
       @join_dependency = join_dependency(@object)
       @join_type = options[:join_type] || Polyamorous::OuterJoin
       @search_key = options[:search_key] || Ransack.options[:search_key]
+      @associations_pot = {}
+      @lock_associations = []
 
       if ::ActiveRecord::VERSION::STRING >= Constants::RAILS_4_1
         @base = @join_dependency.join_root
diff --git a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
index b248bd315..e97ac5def 100644
--- a/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
+++ b/lib/ransack/adapters/active_record/ransack/nodes/condition.rb
@@ -3,33 +3,29 @@ module Nodes
     class Condition
 
       def arel_predicate
-        if attributes.size > 1
-          combinator_for_predicates
-        else
-          format_predicate
-        end
+        attributes.map { |attribute|
+          association = attribute.parent
+          if negative? && attribute.associated_collection?
+            query = context.build_correlated_subquery(association)
+            query.where(format_predicate(attribute).not)
+            context.remove_association(association)
+            Arel::Nodes::NotIn.new(context.primary_key, Arel.sql(query.to_sql))
+          else
+            format_predicate(attribute)
+          end
+        }.reduce(combinator_method)
       end
 
       private
 
-        def arel_predicates
-          attributes.map do |a|
-            a.attr.send(
-              arel_predicate_for_attribute(a), formatted_values_for_attribute(a)
-            )
-          end
-        end
-
-        def combinator_for_predicates
-          if combinator === Constants::AND
-            Arel::Nodes::Grouping.new(arel_predicates.inject(&:and))
-          elsif combinator === Constants::OR
-            arel_predicates.inject(&:or)
-          end
+        def combinator_method
+          combinator === Constants::OR ? :or : :and
         end
 
-        def format_predicate
-          predicate = arel_predicates.first
+        def format_predicate(attribute)
+          arel_pred = arel_predicate_for_attribute(attribute)
+          arel_values = formatted_values_for_attribute(attribute)
+          predicate = attribute.attr.public_send(arel_pred, arel_values)
           if casted_array_with_in_predicate?(predicate)
             predicate.right[0] = format_values_for(predicate.right[0])
           end
diff --git a/lib/ransack/nodes/attribute.rb b/lib/ransack/nodes/attribute.rb
index 3183a3dd0..0eccd46a9 100644
--- a/lib/ransack/nodes/attribute.rb
+++ b/lib/ransack/nodes/attribute.rb
@@ -24,6 +24,10 @@ def valid?
         .include?(attr_name.split('.').last)
       end
 
+      def associated_collection?
+        parent.respond_to?(:reflection) && parent.reflection.collection?
+      end
+
       def type
         if ransacker
           return ransacker.type
diff --git a/lib/ransack/nodes/condition.rb b/lib/ransack/nodes/condition.rb
index 1fe3f288c..09eb8c198 100644
--- a/lib/ransack/nodes/condition.rb
+++ b/lib/ransack/nodes/condition.rb
@@ -131,6 +131,9 @@ def build_attribute(name = nil, ransacker_args = [])
         Attribute.new(@context, name, ransacker_args).tap do |attribute|
           @context.bind(attribute, attribute.name)
           self.attributes << attribute if attribute.valid?
+          if predicate && !negative?
+            @context.lock_association(attribute.parent)
+          end
         end
       end
 
@@ -182,6 +185,10 @@ def hash
 
       def predicate_name=(name)
         self.predicate = Predicate.named(name)
+        unless negative?
+          attributes.each { |a| context.lock_association(a.parent) }
+        end
+        @predicate
       end
       alias :p= :predicate_name=
 
diff --git a/spec/ransack/adapters/active_record/base_spec.rb b/spec/ransack/adapters/active_record/base_spec.rb
index c9d3e97c7..8220746f6 100644
--- a/spec/ransack/adapters/active_record/base_spec.rb
+++ b/spec/ransack/adapters/active_record/base_spec.rb
@@ -94,6 +94,76 @@ module ActiveRecord
           end
         end
 
+        context 'negative conditions on HABTM associations' do
+          let(:medieval) { Tag.create!(name: 'Medieval') }
+          let(:fantasy)  { Tag.create!(name: 'Fantasy') }
+          let(:arthur)   { Article.create!(title: 'King Arthur') }
+          let(:marco)    { Article.create!(title: 'Marco Polo') }
+
+          before do
+            marco.tags << medieval
+            arthur.tags << medieval
+            arthur.tags << fantasy
+          end
+
+          it 'removes redundant joins from top query' do
+            s = Article.ransack(tags_name_not_eq: "Fantasy")
+            sql = s.result.to_sql
+
+            expect(sql).to_not include('LEFT OUTER JOIN')
+          end
+
+          it 'handles != for single values' do
+            s = Article.ransack(tags_name_not_eq: "Fantasy")
+            articles = s.result.to_a
+
+            expect(articles).to include marco
+            expect(articles).to_not include arthur
+          end
+
+          it 'handles NOT IN for multiple attributes' do
+            s = Article.ransack(tags_name_not_in: ["Fantasy", "Scifi"])
+            articles = s.result.to_a
+
+            expect(articles).to include marco
+            expect(articles).to_not include arthur
+          end
+        end
+
+        context 'negative conditions on self-referenced associations' do
+          let(:pop) { Person.create!(name: 'Grandpa') }
+          let(:dad) { Person.create!(name: 'Father') }
+          let(:mom) { Person.create!(name: 'Mother') }
+          let(:son) { Person.create!(name: 'Grandchild') }
+
+          before do
+            son.parent = dad
+            dad.parent = pop
+            dad.children << son
+            mom.children << son
+            pop.children << dad
+            son.save! && dad.save! && mom.save! && pop.save!
+          end
+
+          it 'handles multiple associations and aliases' do
+            s = Person.ransack(
+              c: {
+                '0' => { a: ['name'], p: 'not_eq', v: ['Father'] },
+                '1' => {
+                        a: ['children_name', 'parent_name'],
+                        p: 'not_eq', v: ['Father'], m: 'or'
+                      },
+                '2' => { a: ['children_salary'], p: 'eq', v: [nil] }
+              })
+            people = s.result
+
+            expect(people.to_a).to include son
+            expect(people.to_a).to include mom
+            expect(people.to_a).to_not include dad  # rule '0': 'name'
+            expect(people.to_a).to_not include pop  # rule '1': 'children_name'
+          end
+        end
+
         describe '#ransack_alias' do
           it 'translates an alias to the correct attributes' do
             p = Person.create!(name: 'Meatloaf', email: 'babies@example.com')

From 7f1235adb5a7c0ee3ac01913d076ffc805f66ec0 Mon Sep 17 00:00:00 2001
From: Andrew Vit <andrew@avit.ca>
Date: Tue, 16 Feb 2016 12:30:28 -0800
Subject: [PATCH 11/11] Add new method stubs for mongoid

---
 lib/ransack/adapters/mongoid/context.rb | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/ransack/adapters/mongoid/context.rb b/lib/ransack/adapters/mongoid/context.rb
index b36b24461..f1a1db41f 100644
--- a/lib/ransack/adapters/mongoid/context.rb
+++ b/lib/ransack/adapters/mongoid/context.rb
@@ -96,6 +96,14 @@ def klassify(obj)
           end
         end
 
+        def lock_association(association)
+          warn "lock_association is not implemented for Ransack mongoid adapter" if $DEBUG
+        end
+
+        def remove_association(association)
+          warn "remove_association is not implemented for Ransack mongoid adapter" if $DEBUG
+        end
+
       private
 
         def get_parent_and_attribute_name(str, parent = @base)