Restructure querying into plugin

lib/mobility/active_record.rb

@@ -1,4 +1,6 @@
 # frozen_string_literal: true
+require "mobility/arel"
+
 module Mobility
 =begin
 
@@ -10,24 +12,12 @@ module ActiveRecord
 
     def self.included(model_class)
       model_class.class_eval do
-        extend QueryMethod.new(Mobility.query_method)
         unless const_defined?(:UniquenessValidator)
           const_set(:UniquenessValidator,
                     Class.new(::Mobility::ActiveRecord::UniquenessValidator))
         end
         delegate :translated_attribute_names, to: :class
       end
     end
-
-    class QueryMethod < Module
-      def initialize(query_method)
-        module_eval <<-EOM, __FILE__, __LINE__ + 1
-          def #{query_method}
-            all
-          end
-        EOM
-      end
-    end
-    private_constant :QueryMethod
   end
 end

lib/mobility/arel.rb

@@ -0,0 +1 @@
+require "mobility/arel/nodes"

lib/mobility/arel/nodes.rb

@@ -0,0 +1,16 @@
+# frozen-string-literal: true
+module Mobility
+  module Arel
+    module Nodes
+      class Unary  < ::Arel::Nodes::Unary;  end
+      class Binary < ::Arel::Nodes::Binary; end
+      class Grouping < Unary; end
+      class Equality < Binary; end
+
+      ::Arel::Visitors::ToSql.class_eval do
+        alias :visit_Mobility_Arel_Nodes_Equality :visit_Arel_Nodes_Equality
+        alias :visit_Mobility_Arel_Nodes_Grouping :visit_Arel_Nodes_Grouping
+      end
+    end
+  end
+end

lib/mobility/arel/nodes/pg_ops.rb

@@ -0,0 +1,99 @@
+# frozen-string-literal: true
+require "mobility/arel"
+
+module Mobility
+  module Arel
+    module Nodes
+      %w[
+        JsonDashArrow
+        JsonDashDoubleArrow
+        JsonbDashArrow
+        JsonbQuestion
+        HstoreDashArrow
+        HstoreQuestion
+      ].each do |name|
+        const_set name, (Class.new(Binary) do
+          include ::Arel::Expressions
+          include ::Arel::Predications
+          include ::Arel::OrderPredications
+          include ::Arel::AliasPredication
+
+          def eq(other)
+            Equality.new self, quoted_node(other)
+          end
+        end)
+      end
+
+      JsonbDashArrow.class_eval do
+        def quoted_node(other)
+          other && super(other.to_json)
+        end
+      end
+
+      # Needed for AR 4.2, can be removed when support is deprecated
+      HstoreDashArrow.class_eval do
+        def quoted_node(other)
+          other && super
+        end
+      end
+
+      class Jsonb  < JsonbDashArrow;      end
+      class Hstore < HstoreDashArrow;     end
+      class Json   < JsonDashDoubleArrow; end
+    end
+
+    module Visitors
+      def visit_Mobility_Arel_Nodes_Equality o, a
+        left, right = o.left, o.right
+
+        if right.nil?
+          case left
+          when Nodes::Jsonb
+            nodes = []
+            while Nodes::Jsonb === left
+              left, right = left.left, left.right
+              nodes << Nodes::JsonbQuestion.new(left, right).not
+            end
+            return visit(nodes.inject(&:or), a)
+          when Nodes::Hstore
+            return visit(Nodes::HstoreQuestion.new(left.left, left.right).not, a)
+          end
+        end
+
+        super o, a
+      end
+
+      def visit_Mobility_Arel_Nodes_JsonDashArrow o, a
+        json_infix o, a, '->'
+      end
+
+      def visit_Mobility_Arel_Nodes_JsonDashDoubleArrow o, a
+        json_infix o, a, '->>'
+      end
+
+      def visit_Mobility_Arel_Nodes_JsonbDashArrow o, a
+        json_infix o, a, '->'
+      end
+
+      def visit_Mobility_Arel_Nodes_JsonbQuestion o, a
+        json_infix o, a, '?'
+      end
+
+      def visit_Mobility_Arel_Nodes_HstoreDashArrow o, a
+        json_infix o, a, '->'
+      end
+
+      def visit_Mobility_Arel_Nodes_HstoreQuestion o, a
+        json_infix o, a, '?'
+      end
+
+      private
+
+      def json_infix(o, a, opr)
+        visit(Nodes::Grouping.new(::Arel::Nodes::InfixOperation.new(opr, o.left, o.right)), a)
+      end
+    end
+
+    ::Arel::Visitors::PostgreSQL.include Visitors
+  end
+end

lib/mobility/backends/active_record.rb

@@ -1,19 +1,31 @@
 module Mobility
   module Backends
     module ActiveRecord
-      def setup_query_methods(query_methods)
-        setup do |attributes, options|
-          extend(Module.new do
-            define_method ::Mobility.query_method do
-              super().extending(query_methods.new(attributes, options))
-            end
-          end)
-        end
-      end
-
       def self.included(backend_class)
         backend_class.include(Backend)
-        backend_class.extend(self)
+        backend_class.extend(ClassMethods)
+      end
+
+      module ClassMethods
+        # @param [String] _attr Attribute name
+        # @param [Symbol] _locale Locale
+        def build_node(_attr, _locale)
+          raise NotImplementedError
+        end
+
+        # @param [ActiveRecord::Relation] relation Relation to scope
+        # @param [Symbol] locale Locale
+        # @option [Boolean] invert
+        # @return [ActiveRecord::Relation] Relation with scope added
+        def add_translations(relation, _opts, _locale, invert: false)
+          relation
+        end
+
+        private
+
+        def build_quoted(value)
+          ::Arel::Nodes.build_quoted(value)
+        end
       end
     end
   end

lib/mobility/backends/active_record/column.rb

@@ -34,8 +34,6 @@ class ActiveRecord::Column
       include ActiveRecord
       include Column
 
-      require 'mobility/backends/active_record/column/query_methods'
-
       # @!group Backend Accessors
       # @!macro backend_reader
       def read(locale, _ = {})
@@ -53,7 +51,9 @@ def each_locale
         available_locales.each { |l| yield(l) if present?(l) }
       end
 
-      setup_query_methods(QueryMethods)
+      def self.build_node(attr, locale)
+        model_class.arel_table[Column.column_name_for(attr, locale)]
+      end
 
       private
 

lib/mobility/backends/active_record/container.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 require "mobility/backends/active_record"
+require "mobility/arel/nodes/pg_ops"
 
 module Mobility
   module Backends
@@ -11,14 +12,15 @@ module Backends
     class ActiveRecord::Container
       include ActiveRecord
 
-      require 'mobility/backends/active_record/container/json_query_methods'
-      require 'mobility/backends/active_record/container/jsonb_query_methods'
-
       # @!method column_name
       #   Returns name of json or jsonb column used to store translations
       #   @return [Symbol] (:translations) Name of translations column
       option_reader :column_name
 
+      # @!method column_type
+      #   @return [Symbol] Either :json or :jsonb
+      option_reader :column_type
+
       # @!group Backend Accessors
       #
       # @note Translation may be a string, integer, boolean, hash or array
@@ -55,16 +57,28 @@ def self.configure(options)
       end
       # @!endgroup
 
+      # @param [String] attr Attribute name
+      # @param [Symbol] locale Locale
+      def self.build_node(attr, locale)
+        column        = model_class.arel_table[column_name]
+        quoted_locale = build_quoted(locale)
+        quoted_attr   = build_quoted(attr)
+        case column_type
+        when :json
+          Arel::Nodes::Json.new(Arel::Nodes::JsonDashArrow.new(column, quoted_locale), quoted_attr)
+        when :jsonb
+          Arel::Nodes::Jsonb.new(Arel::Nodes::Jsonb.new(column, quoted_locale), quoted_attr)
+        end
+      end
+
       # @!macro backend_iterator
       def each_locale
         model[column_name].each do |l, v|
           yield l.to_sym if v.present?
         end
       end
 
-      backend_class = self
-
-      setup do |attributes, options|
+      setup do |_attributes, options|
         store options[:column_name], coder: Coder
 
         # Fix for duping depth-2 jsonb column in AR < 5.0
@@ -83,13 +97,6 @@ def initialize_dup(source)
             include const_set(module_name, dupable)
           end
         end
-
-        query_methods = backend_class.const_get("#{options[:column_type].capitalize}QueryMethods")
-        extend(Module.new do
-          define_method ::Mobility.query_method do
-            super().extending(query_methods.new(attributes, options))
-          end
-        end)
       end
 
       private