.

library/include/larra/serialization/auto.hpp

@@ -68,10 +68,23 @@ struct Config<std::string> {
 };
 
 namespace impl {
+template <typename T>
+concept HasParse = requires(xmlpp::Element* e) {
+  { T::Parse(e) } -> std::same_as<T>;
+};
 
 template <typename T, typename V>
 struct Config : V {
   using V::V;
+  constexpr Config()
+    requires HasParse<T>
+      : V(::larra::xmpp::serialization::Config<T>{}) {
+  }
+
+  constexpr Config()
+    requires(!HasParse<T>)
+      : V(AttributeConfig{}) {
+  }
   constexpr auto Base() const -> const V& {
     return static_cast<const V&>(*this);
   }
@@ -116,14 +129,18 @@ consteval auto FindElement(std::string_view field, utempl::TypeList<T> = {}) {
 }
 
 template <auto& Config, typename Info>
-auto ParseField(xmlpp::Element* main) {
+auto ParseField(xmlpp::Element* main) -> std::decay_t<decltype(Config)>::type {
   using Type = std::decay_t<decltype(Config)>::type;
   if constexpr(std::holds_alternative<AttributeConfig>(Config.Base())) {
     xmlpp::Attribute* node = main->get_attribute(Info::kName);
     if(!node) {
       throw AttributeSerializationError(std::format("Attribute [{}] serialization error", Info::kName));
     }
-    return node->get_value();
+    if constexpr(requires(std::string_view view) { Type::Parse(view); }) {
+      return Type::Parse(node->get_value());
+    } else {
+      return node->get_value();
+    }
   } else {
     return ElementSerializer<Type, Config, Info>::Parse(main);
   }

tests/serialization.cpp

@@ -1,5 +1,6 @@
 #include <gtest/gtest.h>
 
+#include <larra/jid.hpp>
 #include <larra/serialization.hpp>
 #include <larra/serialization/auto.hpp>
 #include <larra/serialization/error.hpp>
@@ -55,6 +56,12 @@ struct SomeStruct4 {
   [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct4;
 };
 
+struct SomeStruct5 {
+  static constexpr auto kDefaultName = "some5";
+  BareJid value;
+  [[nodiscard]] static auto Parse(xmlpp::Element* element) -> SomeStruct5;
+};
+
 }  // namespace tests::serialization
 
 namespace serialization {
@@ -63,12 +70,13 @@ template <>
 constexpr auto kSerializationConfig<tests::serialization::SomeStruct> = SerializationConfig<tests::serialization::SomeStruct>{};
 
 template <>
-constexpr auto kSerializationConfig<tests::serialization::SomeStruct2> =
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct2> = SerializationConfig<tests::serialization::SomeStruct2>{};
-    SerializationConfig<tests::serialization::SomeStruct2>{}.With<"value">(serialization::Config<tests::serialization::SomeStruct>{});
 
 template <>
-constexpr auto kSerializationConfig<tests::serialization::SomeStruct4> =
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct4> = SerializationConfig<tests::serialization::SomeStruct4>{};
-    SerializationConfig<tests::serialization::SomeStruct4>{}.With<"value">(serialization::Config<tests::serialization::SomeStruct3>{});
+
+template <>
+constexpr auto kSerializationConfig<tests::serialization::SomeStruct5> = SerializationConfig<tests::serialization::SomeStruct5>{};
 
 }  // namespace serialization
 
@@ -88,7 +96,11 @@ auto tests::serialization::SomeStruct4::Parse(xmlpp::Element* element) -> SomeSt
   return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct4>(element);
 }
 
-TEST(Parse, Auto) {
+auto tests::serialization::SomeStruct5::Parse(xmlpp::Element* element) -> SomeStruct5 {
+  return ::larra::xmpp::serialization::Parse<tests::serialization::SomeStruct5>(element);
+}
+
+TEST(AutoParse, Basic) {
   xmlpp::Document doc;
   auto node = doc.create_root_node("some2");
   node = node->add_child_element("some");
@@ -104,4 +116,13 @@ TEST(Parse, Auto) {
   EXPECT_EQ(c.value.value, 42);
 }
 
+TEST(AutoParse, Attribute) {
+  xmlpp::Document doc;
+  auto node = doc.create_root_node("some5");
+  node->set_attribute("value", "user@server.i2p");
+  auto a = Serialization<tests::serialization::SomeStruct5>::Parse(node);
+  EXPECT_EQ(a.value.server, "server.i2p"sv);
+  EXPECT_EQ(a.value.username, "user"sv);
+}
+
 }  // namespace larra::xmpp