Merge pull request #17615 from NickLaMuro/custom_attributes_as_arel_v…

…irtual_attributes

Changes custom_attribute virtual_attributes to support AREL/SQL

app/models/miq_report.rb

@@ -200,6 +200,11 @@ def page_size
     rpt_options.try(:fetch_path, :pdf, :page_size) || "a4"
   end
 
+  def all_custom_attributes_are_virtual_sql_attributes?
+    ca_va_cols = CustomAttributeMixin.select_virtual_custom_attributes(cols)
+    ca_va_cols.all? { |custom_attribute| va_sql_cols.include?(custom_attribute) }
+  end
+
   def load_custom_attributes
     return unless db_klass < CustomAttributeMixin || Chargeback.db_is_chargeback?(db)
 

app/models/miq_report/generator.rb

@@ -307,6 +307,13 @@ def generate_basic_results(options = {})
     # TODO: add once only_cols is fixed
     # targets = targets.select(only_cols)
     where_clause = MiqExpression.merge_where_clauses(self.where_clause, options[:where_clause])
+
+    # Remove custom_attributes as part of the `includes` if all of them exist
+    # in the select statement
+    if all_custom_attributes_are_virtual_sql_attributes?
+      remove_loading_relations_for_virtual_custom_attributes
+    end
+
     rbac_opts = options.merge(
       :targets          => targets,
       :filter           => conditions,

app/models/mixins/custom_attribute_mixin.rb

@@ -41,19 +41,41 @@ def self.load_custom_attributes_for(cols)
     def self.add_custom_attribute(custom_attribute)
       return if respond_to?(custom_attribute)
 
-      virtual_column(custom_attribute.to_sym, :type => :string, :uses => :custom_attributes)
+      ca_sym                 = custom_attribute.to_sym
+      without_prefix         = custom_attribute.sub(CUSTOM_ATTRIBUTES_PREFIX, "")
+      name_val, section      = without_prefix.split(SECTION_SEPARATOR)
+      sanatized_column_alias = custom_attribute.tr('.', 'DOT').tr('/', 'BS').tr(':', 'CLN')
+      ca_arel                = custom_attribute_arel(name_val, section, sanatized_column_alias)
 
-      define_method(custom_attribute.to_sym) do
-        custom_attribute_without_prefix           = custom_attribute.sub(CUSTOM_ATTRIBUTES_PREFIX, "")
-        custom_attribute_without_section, section = custom_attribute_without_prefix.split(SECTION_SEPARATOR)
+      virtual_column(ca_sym, :type => :string, :uses => :custom_attributes, :arel => ca_arel)
 
-        where_args = {}
-        where_args[:name]    = custom_attribute_without_section
+      define_method(ca_sym) do
+        return self[sanatized_column_alias] if has_attribute?(sanatized_column_alias)
+
+        where_args           = {}
+        where_args[:name]    = name_val
         where_args[:section] = section if section
 
         custom_attributes.find_by(where_args).try(:value)
       end
     end
+
+    def self.custom_attribute_arel(name_val, section, column_alias)
+      lambda do |t|
+        ca_field    = CustomAttribute.arel_table
+
+        field_where = ca_field[:resource_id].eq(t[:id])
+        field_where = field_where.and(ca_field[:resource_type].eq(base_class.name))
+        field_where = field_where.and(ca_field[:name].eq(name_val))
+        field_where = field_where.and(ca_field[:section].eq(section)) if section
+
+        # Because there is a `find_by` in the `define_method` above, we are
+        # using a `take(1)` here as well, since a limit is assumed in each.
+        # Without it, there can be some invalid queries if more than one result
+        # is returned.
+        ca_field.project(:value).where(field_where).take(1).as(column_alias)
+      end
+    end
   end
 
   def self.to_human(column)