reactivated relation_completer

include/matador/object/attribute.hpp

@@ -15,7 +15,6 @@ enum class null_option_type : uint8_t {
 };
 
 class object;
-class attribute_generator;
 
 class attribute {
 public:
@@ -65,7 +64,6 @@ public:
 
 private:
   friend class object;
-  friend class attribute_generator;
   friend class object_generator;
 
   std::string name_;

include/matador/object/attribute_generator.hpp

@@ -1,157 +0,0 @@
-#ifndef QUERY_COLUMN_DEFINITION_GENERATOR_HPP
-#define QUERY_COLUMN_DEFINITION_GENERATOR_HPP
-
-#include "matador/object/attribute.hpp"
-
-#include "matador/utils/access.hpp"
-#include "matador/utils/data_type_traits.hpp"
-#include "matador/utils/error.hpp"
-#include "matador/utils/field_attributes.hpp"
-#include "matador/utils/identifier.hpp"
-#include "matador/utils/primary_key_attribute.hpp"
-#include "matador/utils/result.hpp"
-
-#include <memory>
-#include <typeindex>
-#include <vector>
-
-namespace matador::object {
-
-class repository;
-
-class fk_attribute_generator
-{
-public:
-  fk_attribute_generator() = default;
-
-  template<class Type>
-  attribute generate(const char *id, Type &x) {
-    access::process(*this, x);
-    return attribute{id, type_, {utils::constraints::ForeignKey }, null_option_type::NotNull};
-  }
-
-  template<typename ValueType>
-  void on_primary_key(const char *, ValueType &/*pk*/, const utils::primary_key_attribute& attr = utils::default_pk_attributes) {
-    type_ = utils::data_type_traits<ValueType>::type(attr.size());
-  }
-  static void on_revision(const char * /*id*/, uint64_t &/*rev*/) {}
-  template < class Type >
-  static void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
-  static void on_attribute(const char * /*id*/, char * /*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
-  template<class Pointer>
-  static void on_belongs_to(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
-  template<class Pointer>
-  static void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
-  template<class ContainerType>
-  static void on_has_many(const char * /*id*/, ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
-  template<class ContainerType>
-  static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const char * /*join_column*/, const char * /*inverse_join_column*/, const utils::foreign_attributes &/*attr*/) {}
-  template<class ContainerType>
-  static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const utils::foreign_attributes &/*attr*/) {}
-
-private:
-  utils::basic_type type_{};
-};
-
-class attribute_generator final {
-private:
-  attribute_generator(std::vector<attribute> &columns, const repository &repo, const std::shared_ptr<object>& obj);
-
-public:
-  ~attribute_generator() = default;
-
-  template < class Type >
-  static std::vector<attribute> generate(const repository &repo, const std::shared_ptr<object> &obj) {
-    Type t;
-    return generate(t, repo, obj);
-  }
-
-  template < class Type >
-  static std::vector<attribute> generate(const Type& t, const repository &repo, const std::shared_ptr<object> &obj) {
-    std::vector<attribute> columns;
-    attribute_generator gen(columns, repo, obj);
-    access::process(gen, t);
-    return columns;
-  }
-
-  template < class Type >
-  void on_primary_key(const char *, Type &x, const utils::primary_key_attribute& attr = utils::default_pk_attributes);
-  void on_revision(const char *id, uint64_t &rev);
-
-  template<typename Type>
-  void on_attribute(const char *id, Type &x, const utils::field_attributes &attr = utils::null_attributes);
-
-  template<typename Type>
-  void on_attribute(const char *id, std::optional<Type> &x, const utils::field_attributes &attr = utils::null_attributes);
-
-  template<class Pointer>
-  void on_belongs_to(const char *id, Pointer &x, const utils::foreign_attributes &/*attr*/) {
-    on_foreign_key(id, x);
-  }
-  template<class Pointer>
-  static void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
-
-  template <class Pointer>
-  void on_foreign_key(const char *id, Pointer &x) {
-    attribute* ref_column;
-    std::type_index ti = typeid(typename Pointer::value_type);
-    if (auto result = determine_foreign_ref(std::type_index(ti))) {
-        ref_column = *result;
-    } else {
-        ref_column = nullptr;
-        insert_missing_reference_column(ti, ref_column);
-    }
-    if (x.empty()) {
-      typename Pointer::value_type temp_val;
-      columns_.push_back(fk_column_generator_.generate(id, temp_val));
-    } else {
-      columns_.push_back(fk_column_generator_.generate(id, *x));
-    }
-  }
-  template<class ContainerType>
-  static void on_has_many(const char * /*id*/, ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
-  template<class ContainerType>
-  static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const char * /*join_column*/, const char * /*inverse_join_column*/, const utils::foreign_attributes &/*attr*/) {}
-  template<class ContainerType>
-  static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const utils::foreign_attributes &/*attr*/) {}
-
-private:
-  [[nodiscard]] utils::result<attribute*, utils::error> determine_foreign_ref(const std::type_index &ti) const;
-  void insert_missing_reference_column(const std::type_index &ti, attribute* ref_column) const;
-
-  template<typename ValueType>
-  attribute &emplace_attribute(const char *id, const utils::field_attributes& attr, null_option_type null_option) {
-    auto &ref = columns_.emplace_back(id, utils::data_type_traits<ValueType>::type(attr.size()), attr, null_option);
-    ref.owner_ = obj_;
-    return ref;
-  }
-
-  void prepare_primary_key(attribute &ref, utils::identifier &&pk) const;
-
-private:
-  size_t index_ = 0;
-  std::vector<attribute> &columns_;
-  const repository &repo_;
-  const std::shared_ptr<object> obj_;
-
-  fk_attribute_generator fk_column_generator_;
-};
-
-template<typename ValueType>
-void attribute_generator::on_primary_key(const char *id, ValueType &x, const utils::primary_key_attribute& attr) {
-  auto &ref = emplace_attribute<ValueType>(id, { attr.size(), utils::constraints::PrimaryKey }, null_option_type::NotNull);
-  prepare_primary_key(ref, utils::identifier(x));
-}
-
-template<typename Type>
-void attribute_generator::on_attribute(const char *id, Type &/*x*/, const utils::field_attributes &attr) {
-  std::ignore = emplace_attribute<Type>(id, attr, null_option_type::NotNull);
-}
-
-template<typename Type>
-void attribute_generator::on_attribute(const char *id, std::optional<Type> & /*x*/, const utils::field_attributes &attr) {
-  std::ignore = emplace_attribute<Type>(id, attr, null_option_type::Nullable);
-}
-
-}
-#endif //QUERY_COLUMN_DEFINITION_GENERATOR_HPP

include/matador/object/constraints_generator.hpp

@@ -1,78 +0,0 @@
-#ifndef MATADOR_CONSTRAINTS_GENERATOR_HPP
-#define MATADOR_CONSTRAINTS_GENERATOR_HPP
-
-#include "matador/object/restriction.hpp"
-
-#include "matador/utils/access.hpp"
-#include "matador/utils/field_attributes.hpp"
-#include "matador/utils/primary_key_attribute.hpp"
-
-#include <list>
-#include <typeindex>
-
-namespace matador::object {
-class object;
-class basic_object_info;
-class repository;
-
-class constraints_generator final {
-private:
-    constraints_generator(std::list<class restriction> &constraints, const repository &repo, const std::shared_ptr<object> &obj);
-
-public:
-    constraints_generator() = delete;
-
-    template < typename Type >
-    static std::list<class restriction> generate(const repository &repo, const std::shared_ptr<object> &obj) {
-        Type t;
-        return generate(t, repo, obj);
-    }
-
-    template < typename Type >
-    static std::list<class restriction> generate(const Type& t, const repository &repo, const std::shared_ptr<object> &obj) {
-        std::list<class restriction> constraints;
-        constraints_generator gen(constraints, repo, obj);
-        access::process(gen, t);
-        return constraints;
-    }
-
-    template < class Type >
-    void on_primary_key(const char *id, Type &/*x*/, const utils::primary_key_attribute& /*attr*/ = utils::default_pk_attributes) {
-      create_pk_constraint(id);
-    }
-    static void on_revision(const char * /*id*/, uint64_t &/*rev*/) {}
-    template<typename Type>
-    void on_attribute(const char *id, Type &/*x*/, const utils::field_attributes &attr = utils::null_attributes) {
-      if (utils::is_constraint_set(attr.options() ,utils::constraints::Unique)) {
-        create_unique_constraint(id);
-      }
-    }
-
-    template<class Pointer>
-    void on_belongs_to(const char *id, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {
-      create_fk_constraint( typeid(typename Pointer::value_type), id);
-    }
-    template<class Pointer>
-    static void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
-    template<class ContainerType>
-    static void on_has_many(const char * /*id*/, ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
-    template<class ContainerType>
-    static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const char * /*join_column*/, const char * /*inverse_join_column*/, const utils::foreign_attributes &/*attr*/) {}
-    template<class ContainerType>
-    static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const utils::foreign_attributes &/*attr*/) {}
-
-private:
-    void create_pk_constraint(const std::string& name) const;
-    void create_fk_constraint(const std::type_index& ti, const std::string& name) const;
-    void create_unique_constraint(const std::string& name) const;
-
-    [[nodiscard]] std::list<attribute>::iterator find_attribute_by_name(const std::string &name) const;
-
-private:
-    std::list<class restriction> &constraints_;
-    const repository &repo_;
-    std::shared_ptr<object> obj_;
-};
-}
-
-#endif //MATADOR_CONSTRAINTS_GENERATOR_HPP

include/matador/object/foreign_node_completer.hpp

@@ -29,8 +29,7 @@ private:
 public:
   template<class Type>
   static void complete(const std::shared_ptr<repository_node> &node) {
-    internal::shadow_repository shadow(node->repo_);
+    foreign_node_completer<Type> completer(internal::shadow_repository(node->repo_));
-    foreign_node_completer<Type> completer(shadow);
 
     completer.complete_node(node);
   }
@@ -83,7 +82,7 @@ private:
   }
 
   template<typename Type>
-  void attach_node(const std::string &name = "") {
+  void attach_node(const std::string &name) {
     if (repo_.contains(typeid(Type))) {
       return;
     }
@@ -93,6 +92,18 @@ private:
     }
   }
 
+  template<typename Type>
+  void attach_node() {
+    if (repo_.contains(typeid(Type))) {
+      return;
+    }
+
+    const auto node = repository_node::make_node<Type>(repo_.repo(), "");
+    if (auto result = repo_.attach_node(node)) {
+      complete<Type>(result.value());
+    }
+  }
+
   template<typename Type>
   void attach_relation_node(const std::string &name, const std::string &join_column, const std::string &inverse_join_column) {
     using relation_value_type = many_to_many_relation<Type, NodeType>;
@@ -183,30 +194,31 @@ void foreign_node_completer<NodeType>::on_has_many(const char * /*id*/,
 
 template<typename NodeType>
 template<class CollectionType>
-void foreign_node_completer<NodeType>::on_has_many_to_many(const char *id, CollectionType & /*collection*/,
+void foreign_node_completer<NodeType>::on_has_many_to_many(const char * /*id*/,
-                                                           const char *join_column,
+                                                           CollectionType & /*collection*/,
-                                                           const char *inverse_join_column,
+                                                           const char * /*join_column*/,
+                                                           const char * /*inverse_join_column*/,
                                                            const utils::foreign_attributes & /*attr*/) {
-  if (!repo_.expecting_relation_node(id)) {
+  // if (!repo_.expecting_relation_node(id)) {
-    repo_.expect_relation_node(id, typeid(typename CollectionType::value_type::value_type));
+  //   repo_.expect_relation_node(id, typeid(typename CollectionType::value_type::value_type));
-  } else {
+  // } else {
-    attach_relation_node<typename CollectionType::value_type::value_type>(id, join_column, inverse_join_column);
+  //   attach_relation_node<typename CollectionType::value_type::value_type>(id, join_column, inverse_join_column);
-    repo_.remove_expected_relation_node(id);
+  //   repo_.remove_expected_relation_node(id);
-  }
+  // }
 }
 
 template<typename NodeType>
 template<class CollectionType>
-void foreign_node_completer<NodeType>::on_has_many_to_many(const char *id,
+void foreign_node_completer<NodeType>::on_has_many_to_many(const char * /*id*/,
                                                            CollectionType & /*collection*/,
                                                            const utils::foreign_attributes & /*attr*/) {
-  if (!repo_.expecting_relation_node(id)) {
+  // if (!repo_.expecting_relation_node(id)) {
-    repo_.expect_relation_node(id, typeid(typename CollectionType::value_type::value_type));
+  //   repo_.expect_relation_node(id, typeid(typename CollectionType::value_type::value_type));
-  } else {
+  // } else {
-    const auto join_columns = join_columns_collector_.collect<typename CollectionType::value_type::value_type>();
+  //   const auto join_columns = join_columns_collector_.collect<typename CollectionType::value_type::value_type>();
-    attach_relation_node<typename CollectionType::value_type::value_type>(id, join_columns.join_column, join_columns.inverse_join_column);
+  //   attach_relation_node<typename CollectionType::value_type::value_type>(id, join_columns.join_column, join_columns.inverse_join_column);
-    repo_.remove_expected_relation_node(id);
+  //   repo_.remove_expected_relation_node(id);
-  }
+  // }
 }
 
 template<typename NodeType>

include/matador/object/internal/shadow_repository.hpp

@@ -1,6 +1,8 @@
 #ifndef SHADOW_SCHEMA_HPP
 #define SHADOW_SCHEMA_HPP
 
+#include "matador/object/basic_object_info.hpp"
+
 #include "matador/utils/result.hpp"
 #include "matador/utils/error.hpp"
 
@@ -10,6 +12,7 @@
 namespace matador::object {
 class repository;
 class repository_node;
+class object;
 }
 
 namespace matador::object::internal {
@@ -22,6 +25,7 @@ public:
 
   [[nodiscard]] repository& repo() const;
   [[nodiscard]] bool contains(const std::type_index& ti) const;
+  [[nodiscard]] utils::result<basic_object_info_ref, utils::error> basic_info(const std::type_index& ti) const;
   [[nodiscard]] utils::result<node_ptr, utils::error> find_node(const std::type_index &type_index) const;
   [[nodiscard]] utils::result<node_ptr, utils::error> find_node(const std::string &name) const;
   [[nodiscard]] utils::result<node_ptr, utils::error> attach_node(const std::shared_ptr<repository_node> &node) const;
@@ -31,6 +35,11 @@ public:
   void expect_relation_node(const std::string &name, const std::type_index &ti) const;
   void remove_expected_relation_node(const std::string &name) const;
 
+  [[nodiscard]] std::shared_ptr<object> provide_object_in_advance(const std::type_index &ti, const std::shared_ptr<object>& obj) const;
+  [[nodiscard]] bool has_object_for_type(const std::type_index &ti) const;
+  [[nodiscard]] std::shared_ptr<object> object_for_type(const std::type_index &ti) const;
+  void remove_object_for_type(const std::type_index &ti) const;
+
 private:
   repository& repo_;
 };

include/matador/object/object.hpp

@@ -23,6 +23,7 @@ public:
   [[nodiscard]] const utils::identifier& primary_key() const;
   [[nodiscard]] bool has_primary_key() const;
 
+  [[nodiscard]] bool empty() const;
   [[nodiscard]] const std::string& name() const;
 
   void update_name(const std::string& name);
@@ -33,12 +34,11 @@ public:
 
   [[nodiscard]] bool has_constraints() const;
   [[nodiscard]] size_t constraint_count() const;
-  [[nodiscard]] const std::list<class restriction>& constraints() const;
+  [[nodiscard]] const std::list<restriction>& constraints() const;
 
   friend std::ostream& operator<<(std::ostream& os, const object& obj);
 
 private:
-  friend class constraints_generator;
   friend class attribute_generator;
   friend class object_generator;
 
@@ -46,7 +46,7 @@ private:
   attribute* pk_attribute_{nullptr};
   utils::identifier pk_identifier_;
   std::list<attribute> attributes_;
-  std::list<class restriction> constraints_;
+  std::list<restriction> constraints_;
 };
 }
 #endif //MATADOR_OBJECT_HPP

include/matador/object/object_generator.hpp

@@ -1,6 +1,7 @@
 #ifndef MATADOR_OBJECT_GENERATOR_HPP
 #define MATADOR_OBJECT_GENERATOR_HPP
 
+#include "matador/object/internal/shadow_repository.hpp"
 #include "matador/object/object.hpp"
 
 #include "matador/utils/access.hpp"
@@ -60,7 +61,16 @@ public:
 
     template < class Type >
     static std::shared_ptr<object> generate(std::unique_ptr<Type>&& t, repository &repo, const std::string &name) {
-        auto obj = acquire_object(repo, typeid(Type), name);
+        const internal::shadow_repository shadow_repo(repo);
+        const std::type_index ti(typeid(Type));
+        if (shadow_repo.has_object_for_type(ti)) {
+            auto obj = shadow_repo.object_for_type(ti);
+            shadow_repo.remove_object_for_type(ti);
+            obj->update_name(name);
+            return obj;
+        }
+
+        auto obj = shadow_repo.provide_object_in_advance(ti, std::make_shared<object>(name));
         object_generator gen(repo, obj);
         access::process(gen, *t);
         return obj;
@@ -79,7 +89,7 @@ public:
     template<class Pointer>
     void on_belongs_to(const char *id, Pointer &x, const utils::foreign_attributes &/*attr*/) {
       on_foreign_key(id, x);
-      create_fk_constraint( typeid(typename Pointer::value_type), id);
+      create_fk_constraint<typename Pointer::value_type>(id);
     }
     template<class Pointer>
     static void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
@@ -106,14 +116,16 @@ private:
     }
 
     void create_pk_constraint(const std::string& name) const;
-    void create_fk_constraint(const std::type_index& ti, const std::string& name) const;
+    template<typename Type>
+    void create_fk_constraint(const std::string& name) const;
     void create_unique_constraint(const std::string& name) const;
 
     [[nodiscard]] std::list<attribute>::iterator find_attribute_by_name(const std::string &name) const;
 
     void prepare_primary_key(attribute &ref, utils::identifier &&pk) const;
 
-    [[nodiscard]] std::shared_ptr<class object> fk_object(const std::type_index& ti) const;
+    template<typename Type>
+    [[nodiscard]] std::shared_ptr<object> fk_object() const;
 
     static std::shared_ptr<object> acquire_object(repository &repo, const std::type_index &ti, const std::string& name);
 private:
@@ -138,5 +150,37 @@ void object_generator::on_attribute(const char *id, std::optional<Type> & /*x*/,
     std::ignore = emplace_attribute<Type>(id, attr, null_option_type::Nullable);
 }
 
+template<typename Type>
+void object_generator::create_fk_constraint(const std::string& name) const {
+    const auto pk_attr = find_attribute_by_name(name);
+    if (pk_attr == std::end(object_->attributes_)) {
+        return;
+    }
+    const auto obj = fk_object<Type>();
+    restriction pk_constraint(*pk_attr);
+    pk_constraint.options_ |= utils::constraints::ForeignKey;
+    pk_constraint.owner_ = object_;
+    pk_constraint.reference_ = obj;
+    object_->constraints_.emplace_back(std::move(pk_constraint));
+}
+
+template<typename Type>
+std::shared_ptr<object> object_generator::fk_object() const {
+    const auto ti = std::type_index(typeid(Type));
+    const internal::shadow_repository shadow_repo(repo_);
+    if (const auto result = shadow_repo.basic_info(ti)) {
+        return result->get().object();
+    }
+
+    if (shadow_repo.has_object_for_type(ti)) {
+        return shadow_repo.object_for_type(ti);
+    }
+    const auto obj = shadow_repo.provide_object_in_advance(ti, std::make_shared<object>(""));
+    object_generator gen(repo_, obj);
+    Type t;
+    access::process(gen, t);
+    return obj;
+}
+
 }
 #endif //MATADOR_OBJECT_GENERATOR_HPP

include/matador/object/relation_completer.hpp

@@ -2,6 +2,7 @@
 #define RELATION_COMPLETER_HPP
 
 #include "matador/object/internal/shadow_repository.hpp"
+#include "matador/object/foreign_node_completer.hpp"
 #include "matador/object/many_to_many_relation.hpp"
 #include "matador/object/join_columns_collector.hpp"
 #include "matador/object/object_ptr.hpp"
@@ -143,6 +144,9 @@ private:
       nodes_.pop();
   }
 
+  template<typename NodeType>
+  void attach_relation_node(const std::string &name, const std::string &join_column, const std::string &inverse_join_column);
+
   static void register_relation_endpoints(const endpoint_ptr &endpoint,
                                           const endpoint_ptr &other_endpoint);
   static void link_relation_endpoints(const endpoint_ptr &endpoint,
@@ -244,47 +248,12 @@ void relation_completer<Type>::on_has_many_to_many(const char *id,
                                                    const char *join_column,
                                                    const char *inverse_join_column,
                                                    const utils::foreign_attributes &/*attr*/) {
-  using relation_value_type = many_to_many_relation<typename CollectionType::value_type::value_type, Type>;
+  if (!schema_.expecting_relation_node(id)) {
-  using value_type = typename CollectionType::value_type::value_type;
+    schema_.expect_relation_node(id, typeid(typename CollectionType::value_type::value_type));
-
+  } else {
-  // Check if the object_ptr type is already inserted in the schema (by id)
+    attach_relation_node<typename CollectionType::value_type::value_type>(id, join_column, inverse_join_column);
-  auto result = schema_.find_node(typeid(value_type));
+    schema_.remove_expected_relation_node(id);
-  if (!result) {
-    // Todo: throw internal error or attach node
-    return;
   }
-
-  const auto foreign_node = result.value();
-  result = schema_.find_node(id);
-  if (result) {
-    return;
-  }
-  // Relation not found.
-  auto creator = [join_column, inverse_join_column] {
-    return std::make_unique<relation_value_type>(join_column, inverse_join_column);
-  };
-
-  auto node = repository_node::make_node<relation_value_type>(schema_.repo(), id, std::move(creator));
-  result = schema_.attach_node(node);
-  if (!result) {
-    // Todo: throw internal error
-    return;
-  }
-
-  const auto local_endpoint = std::make_shared<relation_endpoint>(id, relation_type::HasMany, node);
-  const auto join_endpoint = std::make_shared<relation_endpoint>(join_column, relation_type::BelongsTo, nodes_.top());
-  const auto inverse_join_endpoint = std::make_shared<relation_endpoint>(inverse_join_column, relation_type::BelongsTo, foreign_node);
-  const auto foreign_endpoint = std::make_shared<relation_endpoint>(id, relation_type::HasMany, node);
-  // register relation endpoint in local node
-  nodes_.top()->info_->register_relation_endpoint(typeid(typename CollectionType::value_type::value_type), local_endpoint);
-  // register relation endpoint in foreign node
-  foreign_node->info_->register_relation_endpoint(nodes_.top()->type_index(), foreign_endpoint);
-  // register endpoints in relation node
-  node->info_->register_relation_endpoint(nodes_.top()->type_index(), join_endpoint);
-  node->info_->register_relation_endpoint(typeid(typename CollectionType::value_type::value_type), inverse_join_endpoint);
-  // link endpoints
-  link_relation_endpoints(local_endpoint, join_endpoint);
-  link_relation_endpoints(foreign_endpoint, inverse_join_endpoint);
 }
 
 template<typename Type>
@@ -372,6 +341,54 @@ void relation_completer<Type>::on_belongs_to(const char *id,
   }
 }
 
+template<typename Type>
+template<typename NodeType>
+void relation_completer<Type>::attach_relation_node(const std::string &name, const std::string &join_column, const std::string &inverse_join_column) {
+  using relation_value_type = many_to_many_relation<NodeType, Type>;
+  using value_type = NodeType;
+
+  // Check if the object_ptr type is already inserted in the schema (by id)
+  auto result = schema_.find_node(typeid(value_type));
+  if (!result) {
+    // Todo: throw internal error or attach node
+    return;
+  }
+
+  const auto foreign_node = result.value();
+  result = schema_.find_node(name);
+  if (result) {
+    return;
+  }
+  // Relation does not exist. Create it.
+  auto creator = [join_column, inverse_join_column] {
+    return std::make_unique<relation_value_type>(join_column, inverse_join_column);
+  };
+
+  auto node = repository_node::make_node<relation_value_type>(schema_.repo(), name, std::move(creator));
+  result = schema_.attach_node(node);
+  if (!result) {
+    // Todo: throw internal error
+    return;
+  }
+
+  foreign_node_completer<Type>::template complete<relation_value_type>(result.value());
+
+  const auto local_endpoint = std::make_shared<relation_endpoint>(name, relation_type::HasMany, node);
+  const auto join_endpoint = std::make_shared<relation_endpoint>(join_column, relation_type::BelongsTo, nodes_.top());
+  const auto inverse_join_endpoint = std::make_shared<relation_endpoint>(inverse_join_column, relation_type::BelongsTo, foreign_node);
+  const auto foreign_endpoint = std::make_shared<relation_endpoint>(name, relation_type::HasMany, node);
+  // register relation endpoint in local node
+  nodes_.top()->info_->register_relation_endpoint(typeid(value_type), local_endpoint);
+  // register relation endpoint in foreign node
+  foreign_node->info_->register_relation_endpoint(nodes_.top()->type_index(), foreign_endpoint);
+  // register endpoints in relation node
+  node->info_->register_relation_endpoint(nodes_.top()->type_index(), join_endpoint);
+  node->info_->register_relation_endpoint(typeid(value_type), inverse_join_endpoint);
+  // link endpoints
+  link_relation_endpoints(local_endpoint, join_endpoint);
+  link_relation_endpoints(foreign_endpoint, inverse_join_endpoint);
+}
+
 template<typename Type>
 void relation_completer<Type>::register_relation_endpoints(const endpoint_ptr &endpoint,
                                                            const endpoint_ptr &other_endpoint) {

include/matador/object/repository.hpp

@@ -46,7 +46,7 @@ public:
               return utils::failure(result.err());
           }
           foreign_node_completer<Type>::template complete<Type>(node);
-          // relation_completer<Type>::complete(node);
+          relation_completer<Type>::complete(node);
       } else if (!has_node(name)) {
           it->second->update_name(name);
           nodes_by_name_[name] = it->second;
@@ -189,7 +189,6 @@ private:
 private:
   friend class internal::shadow_repository;
   friend class repository_node;
-  friend class attribute_generator;
   template < typename NodeType >
   friend class foreign_node_completer;
   friend class object_generator;

include/matador/object/repository_node.hpp

@@ -1,10 +1,12 @@
 #ifndef SCHEMA_NODE_HPP
 #define SCHEMA_NODE_HPP
 
-#include "matador/object/attribute_generator.hpp"
 #include "matador/object/object_generator.hpp"
 #include "matador/object/object_info.hpp"
 
+#include "matador/utils/error.hpp"
+#include "matador/utils/result.hpp"
+
 #include <memory>
 
 namespace matador::object {

include/matador/object/restriction.hpp

@@ -17,11 +17,9 @@ class object;
 
 class restriction {
 public:
-  restriction() = default;
+  explicit restriction(const class attribute& attr);
-  explicit restriction(std::string name);
 
-  [[nodiscard]] std::string name() const;
+  [[nodiscard]] const class attribute& attribute() const;
-  [[nodiscard]] const class attribute* attribute() const;
   [[nodiscard]] std::string column_name() const;
   [[nodiscard]] std::shared_ptr<object> owner() const;
   [[nodiscard]] bool is_primary_key_constraint() const;
@@ -32,16 +30,14 @@ public:
 
   friend std::ostream& operator<<(std::ostream& os, const restriction& c);
 
-  std::string prefix() const;
+  std::string type_string() const;
 
 private:
   friend class constraint_builder;
-  friend class constraints_generator;
   friend class object_generator;
   friend class object;
 
-  std::string name_;
+  const class attribute& attr_;
-  std::variant<class attribute*, std::string> attr_;
   std::shared_ptr<object> owner_;
   std::shared_ptr<object> reference_;
   utils::constraints options_{utils::constraints::None};

source/core/CMakeLists.txt

@@ -14,9 +14,7 @@ add_library(matador-core STATIC
   ../../include/matador/net/select_fd_sets.hpp
   ../../include/matador/net/socket_interrupter.hpp
   ../../include/matador/object/attribute.hpp
-  ../../include/matador/object/attribute_generator.hpp
   ../../include/matador/object/basic_object_info.hpp
-  ../../include/matador/object/constraints_generator.hpp
   ../../include/matador/object/error_code.hpp
   ../../include/matador/object/foreign_node_completer.hpp
   ../../include/matador/object/internal/shadow_repository.hpp
@@ -79,9 +77,7 @@ add_library(matador-core STATIC
   logger/logger.cpp
   logger/rotating_file_sink.cpp
   object/attribute.cpp
-  object/attribute_generator.cpp
   object/basic_object_info.cpp
-  object/constraints_generator.cpp
   object/error_code.cpp
   object/foreign_node_completer.cpp
   object/internal/shadow_repository.cpp

source/core/object/attribute_generator.cpp

@@ -1,29 +0,0 @@
-#include "matador/object/attribute_generator.hpp"
-#include "matador/object/repository.hpp"
-#include "matador/object/object.hpp"
-
-namespace matador::object {
-
-attribute_generator::attribute_generator(std::vector<attribute> &columns, const repository &repo, const std::shared_ptr<object> &obj)
-: columns_(columns)
-, repo_(repo)
-, obj_(obj)
-{}
-
-void attribute_generator::on_revision(const char *id, uint64_t &rev) {
-  on_attribute(id, rev);
-}
-
-utils::result<attribute*, utils::error> attribute_generator::determine_foreign_ref(const std::type_index &ti) const {
-  return repo_.primary_key_attribute(ti);
-}
-
-void attribute_generator::insert_missing_reference_column(const std::type_index& ti, attribute* ref_column) const {
-  const_cast<repository&>(repo_).missing_references_.insert({ti, ref_column});
-}
-
-void attribute_generator::prepare_primary_key(attribute& ref, utils::identifier &&pk) const {
-  obj_->pk_attribute_ = &ref;
-  obj_->pk_identifier_ = std::move(pk);
-}
-}

source/core/object/constraints_generator.cpp

@@ -1,51 +0,0 @@
-#include "matador/object/constraints_generator.hpp"
-#include "matador/object/object.hpp"
-#include "matador/object/repository.hpp"
-
-#include <algorithm>
-
-namespace matador::object {
-constraints_generator::constraints_generator(std::list<class restriction> &constraints, const repository& repo, const std::shared_ptr<object> &obj)
-: constraints_(constraints)
-, repo_(repo)
-, obj_(obj) {}
-
-void constraints_generator::create_pk_constraint(const std::string& name) const {
-  restriction pk_constraint("PK_" + obj_->name());
-  pk_constraint.options_ |= utils::constraints::PrimaryKey;
-  if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(obj_->attributes_)) {
-      pk_constraint.attr_ = &*pk_attr;
-  }
-  pk_constraint.owner_ = obj_;
-  constraints_.emplace_back(std::move(pk_constraint));
-}
-
-void constraints_generator::create_fk_constraint(const std::type_index& ti, const std::string& name) const {
-  const auto result = repo_.basic_info(ti);
-  if (!result) {
-    return;
-  }
-  restriction pk_constraint("FK_" + obj_->name() + "_" + name);
-  pk_constraint.options_ |= utils::constraints::ForeignKey;
-  if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(obj_->attributes_)) {
-    pk_constraint.attr_ = &*pk_attr;
-  }
-  pk_constraint.owner_ = obj_;
-  constraints_.emplace_back(std::move(pk_constraint));
-}
-
-void constraints_generator::create_unique_constraint(const std::string& name) const {
-  class restriction pk_constraint("UK_" + obj_->name() + "_" + name);
-  pk_constraint.options_ |= utils::constraints::Unique;
-  if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(obj_->attributes_)) {
-    pk_constraint.attr_ = &*pk_attr;
-  }
-  pk_constraint.owner_ = obj_;
-}
-
-std::list<attribute>::iterator constraints_generator::find_attribute_by_name(const std::string& name) const {
-  return std::find_if(std::begin(obj_->attributes_), std::end(obj_->attributes_), [&name](const attribute& elem) {
-    return elem.name() == name;
-  });
-}
-}

source/core/object/internal/shadow_repository.cpp

@@ -15,6 +15,10 @@ bool shadow_repository::contains( const std::type_index& ti ) const {
   return repo_.contains(ti);
 }
 
+utils::result<basic_object_info_ref, utils::error> shadow_repository::basic_info(const std::type_index& ti) const {
+  return repo_.basic_info(ti);
+}
+
 utils::result<shadow_repository::node_ptr, utils::error> shadow_repository::find_node( const std::type_index& type_index ) const {
   return repo_.find_node(type_index);
 }
@@ -42,4 +46,20 @@ void shadow_repository::expect_relation_node(const std::string &name, const std:
 void shadow_repository::remove_expected_relation_node(const std::string &name) const {
   repo_.remove_expected_relation_node(name);
 }
+
+std::shared_ptr<object> shadow_repository::provide_object_in_advance(const std::type_index& ti, const std::shared_ptr<object>& obj) const {
+  return repo_.provide_object_in_advance(ti, obj);
+}
+
+bool shadow_repository::has_object_for_type(const std::type_index& ti) const {
+  return repo_.has_object_for_type(ti);
+}
+
+std::shared_ptr<object> shadow_repository::object_for_type(const std::type_index& ti) const {
+  return repo_.object_for_type(ti);
+}
+
+void shadow_repository::remove_object_for_type(const std::type_index& ti) const {
+  repo_.remove_object_for_type(ti);
+}
 }

source/core/object/object.cpp

@@ -2,9 +2,7 @@
 
 namespace matador::object {
 object::object(std::string name)
-: name_(std::move(name)) {
+: name_(std::move(name)) {}
-    int i = 9;
-}
 
 const attribute& object::create_attribute(std::string name, const std::shared_ptr<object>& obj) {
   attribute attr{std::move(name)};
@@ -30,13 +28,6 @@ const std::string& object::name() const {
 
 void object::update_name(const std::string& name) {
   name_ = name;
-  // for (auto& con : constraints_) {
-  //     if (con.is_primary_key_constraint()) {
-  //         con.name_ += name;
-  //     } else if (con.is_foreign_key_constraint()) {
-  //         con.name_ = "FK_" + name + "_" + con.column_name();
-  //     }
-  // }
 }
 
 bool object::has_attributes() const {
@@ -59,7 +50,7 @@ size_t object::constraint_count() const {
   return constraints_.size();
 }
 
-const std::list<class restriction>& object::constraints() const {
+const std::list<restriction>& object::constraints() const {
   return constraints_;
 }
 

source/core/object/object_generator.cpp

@@ -25,33 +25,23 @@ void object_generator::on_revision(const char* id, uint64_t& rev) {
 }
 
 void object_generator::create_pk_constraint(const std::string& name) const {
-    restriction pk_constraint("PK_" + object_->name());
+    const auto pk_attr = find_attribute_by_name(name);
+    if (pk_attr == std::end(object_->attributes_)) {
+      return;
+    }
+    restriction pk_constraint(*pk_attr);
     pk_constraint.options_ |= utils::constraints::PrimaryKey;
-    if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(object_->attributes_)) {
-        pk_constraint.attr_ = &*pk_attr;
-    }
     pk_constraint.owner_ = object_;
     object_->constraints_.emplace_back(std::move(pk_constraint));
 }
 
-void object_generator::create_fk_constraint(const std::type_index& ti, const std::string& name) const {
-    const auto obj = fk_object(ti);
-    restriction pk_constraint("FK_" + object_->name() + "_" + name);
-    pk_constraint.options_ |= utils::constraints::ForeignKey;
-    if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(object_->attributes_)) {
-        pk_constraint.attr_ = &*pk_attr;
-    }
-    pk_constraint.owner_ = object_;
-    pk_constraint.reference_ = obj;
-    object_->constraints_.emplace_back(std::move(pk_constraint));
-}
-
 void object_generator::create_unique_constraint(const std::string& name) const {
-    restriction pk_constraint("UK_" + object_->name() + "_" + name);
+    const auto pk_attr = find_attribute_by_name(name);
-    pk_constraint.options_ |= utils::constraints::Unique;
+    if (pk_attr == std::end(object_->attributes_)) {
-    if (const auto pk_attr = find_attribute_by_name(name); pk_attr != std::end(object_->attributes_)) {
+        return;
-        pk_constraint.attr_ = &*pk_attr;
     }
+    restriction pk_constraint(*pk_attr);
+    pk_constraint.options_ |= utils::constraints::Unique;
     pk_constraint.owner_ = object_;
 }
 
@@ -65,16 +55,4 @@ void object_generator::prepare_primary_key(attribute& ref, utils::identifier &&p
     object_->pk_attribute_ = &ref;
     object_->pk_identifier_ = std::move(pk);
 }
-
-std::shared_ptr<class object> object_generator::fk_object(const std::type_index& ti) const {
-  const auto result = repo_.basic_info(ti);
-  if (result) {
-    return result->get().object();
-  }
-
-  if (repo_.has_object_for_type(ti)) {
-    return repo_.object_for_type(ti);
-  }
-  return repo_.provide_object_in_advance(ti, std::make_shared<object>(""));
-}
 }

source/core/object/restriction.cpp

@@ -4,32 +4,16 @@
 #include "matador/object/object.hpp"
 
 namespace matador::object {
-restriction::restriction(std::string name)
+restriction::restriction(const class attribute& attr)
-: name_(std::move(name)) {}
+: attr_(attr) {}
 
-std::string restriction::name() const {
+const class attribute& restriction::attribute() const {
-  return prefix() + name_;
+  return attr_;
-}
-
-const class attribute* restriction::attribute() const {
-  if (std::holds_alternative<class attribute*>(attr_)) {
-    return std::get<class attribute*>(attr_);
-  }
-
-  return nullptr;
 }
 
 std::string restriction::column_name() const {
-    if (std::holds_alternative<class attribute*>(attr_)) {
+  return attr_.name();
-        return std::get<class attribute*>(attr_)->name();
 }
-    if (std::holds_alternative<std::string>(attr_)) {
-        return std::get<std::string>(attr_);
-    }
-
-    return "";
-}
-
 std::shared_ptr<object> restriction::owner() const {
   return owner_;
 }
@@ -55,21 +39,24 @@ const std::string& restriction::ref_column_name() const {
 }
 
 std::ostream & operator<<(std::ostream &os, const class restriction &c) {
-  os << "constraint " << c.name() << " for column " << c.column_name();
+  os << "constraint " << c.type_string() << " for column " << c.column_name();
+  if (c.is_foreign_key_constraint()) {
+    os << " references " << c.ref_table_name() << "." << c.ref_column_name();
+  }
   return os;
 }
 
-std::string restriction::prefix() const {
+std::string restriction::type_string() const {
     if (utils::is_constraint_set(options_, utils::constraints::PrimaryKey)) {
-        return "PK_";
+        return "PrimaryKey";
     }
     if (utils::is_constraint_set(options_, utils::constraints::ForeignKey)) {
-        return "FK_";
+        return "ForeignKey";
     }
     if (utils::is_constraint_set(options_, utils::constraints::Unique)) {
-        return "UK_";
+        return "Unique";
     }
-    return "";
+    return "Unknown";
 }
 
 // constraint_builder & constraint_builder::constraint(std::string name) {

test/core/CMakeLists.txt

@@ -5,7 +5,6 @@ list(APPEND CMAKE_MODULE_PATH ${catch2_SOURCE_DIR}/extras)
 add_executable(CoreTests
   ../backends/SchemaFixture.hpp
   logger/LoggerTest.cpp
-  object/AttributeGeneratorTest.cpp
   object/ObjectTest.cpp
   object/PrimaryKeyResolverTest.cpp
   object/SchemaTest.cpp

test/core/object/AttributeGeneratorTest.cpp

@@ -1,64 +0,0 @@
-#include <catch2/catch_test_macros.hpp>
-
-#include "matador/object/attribute_generator.hpp"
-#include "matador/object/object.hpp"
-#include "matador/object/repository.hpp"
-
-#include "../test/models/product.hpp"
-#include "../test/models/optional.hpp"
-
-using namespace matador::object;
-using namespace matador::utils;
-
-TEST_CASE("Generate column definitions from object", "[column][definition][generator]") {
-  repository repo("main");
-
-  auto result = repo.attach<matador::test::product>("products")
-    .and_then([&repo] { return repo.attach<matador::test::supplier>("supplier"); })
-    .and_then([&repo] { return repo.attach<matador::test::category>("categories"); });
-  REQUIRE(result);
-
-  auto obj = std::make_shared<object>("products");
-  auto columns = attribute_generator::generate<matador::test::product>(repo, obj);
-
-  const std::vector expected_columns = {
-    attribute{"product_name", basic_type::Varchar, constraints::PrimaryKey, null_option_type::NotNull },
-    attribute{"supplier_id", basic_type::UInt32, constraints::ForeignKey, null_option_type::NotNull },
-    attribute{"category_id", basic_type::UInt32, constraints::ForeignKey, null_option_type::NotNull },
-    attribute{"quantity_per_unit", basic_type::Varchar, null_attributes, null_option_type::NotNull },
-    attribute{"unit_price", basic_type::UInt32, null_attributes, null_option_type::NotNull },
-    attribute{"units_in_stock", basic_type::UInt32, null_attributes, null_option_type::NotNull },
-    attribute{"units_in_order", basic_type::UInt32, null_attributes, null_option_type::NotNull },
-    attribute{"reorder_level", basic_type::UInt32, null_attributes, null_option_type::NotNull },
-    attribute{"discontinued", basic_type::Boolean, null_attributes, null_option_type::NotNull }
-  };
-  REQUIRE(!columns.empty());
-  REQUIRE(columns.size() == expected_columns.size());
-
-  for (size_t i = 0; i != expected_columns.size(); ++i) {
-    REQUIRE(expected_columns[i].name() == columns[i].name());
-    REQUIRE(expected_columns[i].attributes().options() == columns[i].attributes().options() );
-    REQUIRE(expected_columns[i].type() == columns[i].type() );
-  }
-}
-
-TEST_CASE("Generate columns from object with nullable columns", "[column generator]") {
-  repository repo("main");
-
-  auto obj = std::make_shared<object>("optionals");
-  auto columns = attribute_generator::generate<matador::test::optional>(repo, obj);
-
-  const std::vector expected_columns = {
-    attribute{"id", basic_type::UInt32, constraints::PrimaryKey, null_option_type::NotNull },
-    attribute{"name", basic_type::Varchar, null_attributes, null_option_type::NotNull },
-    attribute{"age", basic_type::UInt32, null_attributes, null_option_type::NotNull }
-  };
-  REQUIRE(!columns.empty());
-  REQUIRE(columns.size() == expected_columns.size());
-
-  for (size_t i = 0; i != expected_columns.size(); ++i) {
-    REQUIRE(expected_columns[i].name() == columns[i].name());
-    REQUIRE(expected_columns[i].attributes().options() == columns[i].attributes().options() );
-    REQUIRE(expected_columns[i].type() == columns[i].type() );
-  }
-}