feat: improve performance by avoiding unnecessary jointure on belongsTo relations

app/serializers/forest_liana/serializer_factory.rb

@@ -118,12 +118,6 @@ def relationship_related_link(attribute_name)
 
           if ret[:href].blank?
             begin
-              if @options[:include].try(:include?, attribute_name.to_s) &&
-                !SchemaHelper.is_smart_field?(object.class, attribute_name.to_s)
-
-                object.send(attribute_name)
-              end
-
               SchemaUtils.many_associations(object.class).each do |a|
                 if a.name == attribute_name
                   ret[:href] = "/forest/#{ForestLiana.name_for(object.class)}/#{object.id}/relationships/#{attribute_name}"
@@ -137,6 +131,30 @@ def relationship_related_link(attribute_name)
           ret
         end
 
+        def has_one_relationships
+          return {} if self.class.to_one_associations.nil?
+          data = {}
+          self.class.to_one_associations.each do |attribute_name, attr_data|
+            relation = object.class.reflect_on_all_associations.find { |a| a.name == attribute_name }
+
+            next if !should_include_attr?(attribute_name, attr_data)
+
+            unless relation.polymorphic?
+              relation_class_name = ForestLiana.name_for(relation.klass).demodulize
+
+              if object.send(relation.foreign_key.to_sym) &&
+                @options[:fields][relation_class_name]&.size == 1 &&
+                @options[:fields][relation_class_name]&.include?(relation.klass.primary_key.to_sym)
+
+                attr_data[:attr_or_block] = proc {  relation.klass.new(relation.klass.primary_key => object.send(relation.foreign_key.to_sym)) }
+              end
+            end
+
+            data[attribute_name] = attr_data
+          end
+          data
+        end
+
         private
 
         def intercom_integration?

app/services/forest_liana/base_getter.rb

@@ -19,11 +19,12 @@ def includes_for_serialization
 
     def compute_includes
       @includes = ForestLiana::QueryHelper.get_one_association_names_symbol(@resource)
+      @optional_includes = []
     end
 
     def optimize_record_loading(resource, records, force_preload = true)
       polymorphic, preload_loads = analyze_associations(resource)
-      result = records.eager_load(@includes.uniq - preload_loads - polymorphic)
+      result = records.eager_load(@includes.uniq - preload_loads - polymorphic - @optional_includes)
 
       result = result.preload(preload_loads) if Rails::VERSION::MAJOR >= 7 && force_preload
 

app/services/forest_liana/has_many_getter.rb

@@ -37,6 +37,8 @@ def records
     private
 
     def compute_includes
+      @optional_includes = []
+
       @includes = @association.klass
         .reflect_on_all_associations
         .select do |association|

app/services/forest_liana/resources_getter.rb

@@ -31,7 +31,7 @@ def self.get_ids_from_request(params, user)
 
     def perform
       polymorphic_association, preload_loads = analyze_associations(@resource)
-      includes = @includes.uniq - polymorphic_association - preload_loads
+      includes = @includes.uniq - polymorphic_association - preload_loads - @optional_includes
       has_smart_fields =  @params[:fields][@collection_name].split(',').any? do |field|
         ForestLiana::SchemaHelper.is_smart_field?(@resource, field)
       end
@@ -132,26 +132,38 @@ def columns_for_cross_database_association(association_name)
 
     def compute_includes
       associations_has_one = ForestLiana::QueryHelper.get_one_associations(@resource)
+      @optional_includes = []
+      if @field_names_requested
+        includes = associations_has_one.map do |association|
+          association_name = association.name.to_s
 
-      includes = associations_has_one.map(&:name)
-      includes_for_smart_search = []
+          if @params[:fields].key?(association_name) &&
+            @params[:fields][association_name].split(',').size == 1 &&
+            @params[:fields][association_name].split(',').include?(association.klass.primary_key)
 
-      if @collection && @collection.search_fields
-        includes_for_smart_search = @collection.search_fields
-                                               .select { |field| field.include? '.' }
-                                               .map { |field| field.split('.').first.to_sym }
+            @field_names_requested << association.foreign_key
+            @optional_includes << association.name
+          end
 
-        includes_has_many = SchemaUtils.many_associations(@resource)
-                                       .select { |association| SchemaUtils.model_included?(association.klass) }
-                                       .map(&:name)
+          association.name
+        end
 
-        includes_for_smart_search = includes_for_smart_search & includes_has_many
-      end
+        includes_for_smart_search = []
+        if @collection && @collection.search_fields
+          includes_for_smart_search = @collection.search_fields
+                                                 .select { |field| field.include? '.' }
+                                                 .map { |field| field.split('.').first.to_sym }
+
+          includes_has_many = SchemaUtils.many_associations(@resource)
+                                         .select { |association| SchemaUtils.model_included?(association.klass) }
+                                         .map(&:name)
+
+          includes_for_smart_search = includes_for_smart_search & includes_has_many
+        end
 
-      if @field_names_requested
         @includes = (includes & @field_names_requested).concat(includes_for_smart_search)
       else
-        @includes = includes
+        @includes = associations_has_one.map(&:name)
       end
     end
 
@@ -298,7 +310,7 @@ def pagination?
 
     def compute_select_fields
       select = ['_forest_admin_eager_load']
-      @params[:fields][@collection_name].split(',').each do |path|
+      @field_names_requested.each do |path|
         association = get_one_association(path)
         if association
           while association.options[:through]