From e6fa19ff39b01d8773af52172936023d53d12677 Mon Sep 17 00:00:00 2001
From: Bartek Kryza <bkryza@gmail.com>
Date: Sat, 27 May 2023 22:31:46 +0200
Subject: [PATCH] Refactored nested diagrams with element_view template

---
 src/class_diagram/model/diagram.cc            | 407 ++----------------
 src/class_diagram/model/diagram.h             | 203 +++++++--
 .../visitor/translation_unit_visitor.cc       |  30 +-
 src/common/model/diagram_filter.cc            |  14 +-
 src/common/model/element_view.h               |  70 +++
 src/include_diagram/model/diagram.cc          |  38 +-
 src/include_diagram/model/diagram.h           |  62 ++-
 src/package_diagram/model/diagram.cc          |  75 +---
 src/package_diagram/model/diagram.h           | 118 ++++-
 .../visitor/translation_unit_visitor.cc       |   4 +-
 10 files changed, 445 insertions(+), 576 deletions(-)
 create mode 100644 src/common/model/element_view.h

diff --git a/src/class_diagram/model/diagram.cc b/src/class_diagram/model/diagram.cc
index 473d2e10..b250ca86 100644
--- a/src/class_diagram/model/diagram.cc
+++ b/src/class_diagram/model/diagram.cc
@@ -21,20 +21,21 @@
 #include "util/error.h"
 #include "util/util.h"
 
-#include <cassert>
-
 namespace clanguml::class_diagram::model {
 
 const common::reference_vector<class_> &diagram::classes() const
 {
-    return classes_;
+    return element_view<class_>::view();
 }
 
-const common::reference_vector<enum_> &diagram::enums() const { return enums_; }
+const common::reference_vector<enum_> &diagram::enums() const
+{
+    return element_view<enum_>::view();
+}
 
 const common::reference_vector<concept_> &diagram::concepts() const
 {
-    return concepts_;
+    return element_view<concept_>::view();
 }
 
 common::model::diagram_t diagram::type() const
@@ -46,17 +47,17 @@ common::optional_ref<clanguml::common::model::diagram_element> diagram::get(
     const std::string &full_name) const
 {
     common::optional_ref<clanguml::common::model::diagram_element> res =
-        get_class(full_name);
+        find<class_>(full_name);
 
     if (res.has_value())
         return res;
 
-    res = get_enum(full_name);
+    res = find<enum_>(full_name);
 
     if (res.has_value())
         return res;
 
-    res = get_concept(full_name);
+    res = find<concept_>(full_name);
 
     return res;
 }
@@ -66,163 +67,24 @@ common::optional_ref<clanguml::common::model::diagram_element> diagram::get(
 {
     common::optional_ref<clanguml::common::model::diagram_element> res;
 
-    res = get_class(id);
+    res = find<class_>(id);
 
     if (res.has_value())
         return res;
 
-    res = get_enum(id);
+    res = find<enum_>(id);
 
     if (res.has_value())
         return res;
 
-    res = get_concept(id);
+    res = find<concept_>(id);
 
     return res;
 }
 
-bool diagram::has_class(const class_ &c) const
-{
-    return std::any_of(classes_.cbegin(), classes_.cend(),
-        [&c](const auto &cc) { return cc.get() == c; });
-}
-
-bool diagram::has_enum(const enum_ &e) const
-{
-    return std::any_of(enums_.cbegin(), enums_.cend(),
-        [&e](const auto &ee) { return ee.get().full_name() == e.full_name(); });
-}
-
-bool diagram::has_concept(const concept_ &c) const
-{
-    return std::any_of(concepts_.cbegin(), concepts_.cend(),
-        [&c](const auto &cc) { return cc.get() == c; });
-}
-
-common::optional_ref<class_> diagram::get_class(const std::string &name) const
-{
-    for (const auto &c : classes_) {
-        const auto full_name = c.get().full_name(false);
-
-        if (full_name == name) {
-            return {c};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<class_> diagram::get_class(
-    clanguml::common::model::diagram_element::id_t id) const
-{
-    for (const auto &c : classes_) {
-        if (c.get().id() == id) {
-            return {c};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<enum_> diagram::get_enum(const std::string &name) const
-{
-    for (const auto &e : enums_) {
-        if (e.get().full_name(false) == name) {
-            return {e};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<enum_> diagram::get_enum(
-    clanguml::common::model::diagram_element::id_t id) const
-{
-    for (const auto &e : enums_) {
-        if (e.get().id() == id) {
-            return {e};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<concept_> diagram::get_concept(
-    const std::string &name) const
-{
-    for (const auto &c : concepts_) {
-        const auto full_name = c.get().full_name(false);
-
-        if (full_name == name) {
-            return {c};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<concept_> diagram::get_concept(
-    clanguml::common::model::diagram_element::id_t id) const
-{
-    for (const auto &c : concepts_) {
-        if (c.get().id() == id) {
-            return {c};
-        }
-    }
-
-    return {};
-}
-
-bool diagram::add_class(
-    const common::model::path &parent_path, std::unique_ptr<class_> &&c)
-{
-    if (parent_path.type() == common::model::path_type::kNamespace) {
-        return add_class_ns(std::move(c));
-    }
-
-    return add_class_fs(parent_path, std::move(c));
-}
-
-bool diagram::add_enum(const path &parent_path, std::unique_ptr<enum_> &&e)
-{
-    if (parent_path.type() == common::model::path_type::kNamespace) {
-        return add_enum_ns(std::move(e));
-    }
-
-    return add_enum_fs(parent_path, std::move(e));
-}
-
-bool diagram::add_concept(
-    const path &parent_path, std::unique_ptr<concept_> &&c)
-{
-    if (parent_path.type() == common::model::path_type::kNamespace) {
-        return add_concept_ns(std::move(c));
-    }
-
-    return add_concept_fs(parent_path, std::move(c));
-}
-
-bool diagram::add_package(
-    const path &parent_path, std::unique_ptr<common::model::package> &&p)
-{
-    if (parent_path.type() == common::model::path_type::kNamespace) {
-        return add_package_ns(std::move(p));
-    }
-
-    return add_package_fs(parent_path, std::move(p));
-}
-
-bool diagram::add_package_fs(
-    const path &parent_path, std::unique_ptr<common::model::package> &&p)
-{
-    LOG_DBG("Adding filesystem package: {}, {}", p->name(), p->full_name(true));
-
-    auto ns = p->get_relative_namespace();
-
-    return add_element(ns, std::move(p));
-}
-
-bool diagram::add_package_ns(std::unique_ptr<common::model::package> &&p)
+template <>
+bool diagram::add_with_namespace_path<common::model::package>(
+    std::unique_ptr<common::model::package> &&p)
 {
     LOG_DBG("Adding namespace package: {}, {}", p->name(), p->full_name(true));
 
@@ -231,223 +93,16 @@ bool diagram::add_package_ns(std::unique_ptr<common::model::package> &&p)
     return add_element(ns, std::move(p));
 }
 
-bool diagram::add_class_fs(
-    const common::model::path &parent_path, std::unique_ptr<class_> &&c)
+template <>
+bool diagram::add_with_filesystem_path<common::model::package>(
+    const common::model::path &parent_path,
+    std::unique_ptr<common::model::package> &&p)
 {
-    // Make sure all parent directories are already packages in the
-    // model
-    for (auto it = parent_path.begin(); it != parent_path.end(); it++) {
-        auto pkg =
-            std::make_unique<common::model::package>(c->using_namespace());
-        pkg->set_name(*it);
-        auto ns = common::model::path(parent_path.begin(), it);
-        // ns.pop_back();
-        pkg->set_namespace(ns);
-        pkg->set_id(common::to_id(pkg->full_name(false)));
+    LOG_DBG("Adding filesystem package: {}, {}", p->name(), p->full_name(true));
 
-        add_package_fs(ns, std::move(pkg));
-    }
+    auto ns = p->get_relative_namespace();
 
-    const auto base_name = c->name();
-    const auto full_name = c->full_name(false);
-    const auto id = c->id();
-    auto cc = std::ref(*c);
-
-    if (add_element(parent_path, std::move(c))) {
-        classes_.push_back(cc);
-        return true;
-    }
-    else {
-        LOG_WARN("Cannot add class {} with id {} due to: {}", base_name, id);
-    }
-
-    return false;
-}
-
-bool diagram::add_class_ns(std::unique_ptr<class_> &&c)
-{
-    const auto base_name = c->name();
-    const auto full_name = c->full_name(false);
-
-    LOG_DBG("Adding class: {}::{}, {}", c->get_namespace().to_string(),
-        base_name, full_name);
-
-    if (util::contains(base_name, "::"))
-        throw std::runtime_error("Name cannot contain namespace: " + base_name);
-
-    if (util::contains(base_name, "*"))
-        throw std::runtime_error("Name cannot contain *: " + base_name);
-
-    const auto ns = c->get_relative_namespace();
-    auto name = base_name;
-    auto name_with_ns = c->name_and_ns();
-    auto name_and_ns = ns | name;
-    auto &cc = *c;
-    auto id = cc.id();
-
-    try {
-        if (!has_class(cc)) {
-            if (add_element(ns, std::move(c)))
-                classes_.push_back(std::ref(cc));
-
-            const auto &el = get_element<class_>(name_and_ns).value();
-
-            if ((el.name() != name) || !(el.get_relative_namespace() == ns))
-                throw std::runtime_error(
-                    "Invalid element stored in the diagram tree");
-
-            LOG_DBG("Added class {} ({} - [{}])", base_name, full_name, id);
-
-            return true;
-        }
-    }
-    catch (const std::runtime_error &e) {
-        LOG_WARN(
-            "Cannot add class {} with id {} due to: {}", name, id, e.what());
-        return false;
-    }
-
-    LOG_DBG(
-        "Class {} ({} - [{}]) already in the model", base_name, full_name, id);
-
-    return false;
-}
-
-bool diagram::add_enum_ns(std::unique_ptr<enum_> &&e)
-{
-    const auto full_name = e->name();
-
-    LOG_DBG("Adding enum: {}", full_name);
-
-    assert(!util::contains(e->name(), "::"));
-
-    auto e_ref = std::ref(*e);
-    auto ns = e->get_relative_namespace();
-
-    if (!has_enum(*e)) {
-        if (add_element(ns, std::move(e))) {
-            enums_.emplace_back(e_ref);
-            return true;
-        }
-    }
-
-    LOG_DBG("Enum {} already in the model", full_name);
-
-    return false;
-}
-
-bool diagram::add_enum_fs(
-    const common::model::path &parent_path, std::unique_ptr<enum_> &&e)
-{
-    // Make sure all parent directories are already packages in the
-    // model
-    for (auto it = parent_path.begin(); it != parent_path.end(); it++) {
-        auto pkg =
-            std::make_unique<common::model::package>(e->using_namespace());
-        pkg->set_name(*it);
-        auto ns = common::model::path(parent_path.begin(), it);
-        // ns.pop_back();
-        pkg->set_namespace(ns);
-        pkg->set_id(common::to_id(pkg->full_name(false)));
-
-        add_package_fs(ns, std::move(pkg));
-    }
-
-    const auto base_name = e->name();
-    const auto full_name = e->full_name(false);
-    const auto id = e->id();
-    auto &cc = *e;
-
-    if (add_element(parent_path, std::move(e))) {
-        enums_.push_back(std::ref(cc));
-        return true;
-    }
-    else {
-        LOG_WARN("Cannot add class {} with id {} due to: {}", base_name, id);
-    }
-
-    return false;
-}
-
-bool diagram::add_concept_ns(std::unique_ptr<concept_> &&c)
-{
-    const auto base_name = c->name();
-    const auto full_name = c->full_name(false);
-
-    LOG_DBG("Adding concept: {}::{}, {}", c->get_namespace().to_string(),
-        base_name, full_name);
-
-    if (util::contains(base_name, "::"))
-        throw std::runtime_error("Name cannot contain namespace: " + base_name);
-
-    if (util::contains(base_name, "*"))
-        throw std::runtime_error("Name cannot contain *: " + base_name);
-
-    const auto ns = c->get_relative_namespace();
-    auto name = base_name;
-    auto name_with_ns = c->name_and_ns();
-    auto name_and_ns = ns | name;
-    auto &cc = *c;
-    auto id = cc.id();
-
-    try {
-        if (!has_concept(cc)) {
-            if (add_element(ns, std::move(c)))
-                concepts_.push_back(std::ref(cc));
-
-            const auto &el = get_element<concept_>(name_and_ns).value();
-
-            if ((el.name() != name) || !(el.get_relative_namespace() == ns))
-                throw std::runtime_error(
-                    "Invalid element stored in the diagram tree");
-
-            LOG_DBG("Added concept {} ({} - [{}])", base_name, full_name, id);
-
-            return true;
-        }
-    }
-    catch (const std::runtime_error &e) {
-        LOG_WARN(
-            "Cannot add concept {} with id {} due to: {}", name, id, e.what());
-        return false;
-    }
-
-    LOG_DBG("Concept {} ({} - [{}]) already in the model", base_name, full_name,
-        id);
-
-    return false;
-}
-
-bool diagram::add_concept_fs(
-    const common::model::path &parent_path, std::unique_ptr<concept_> &&c)
-{
-    // Make sure all parent directories are already packages in the
-    // model
-    for (auto it = parent_path.begin(); it != parent_path.end(); it++) {
-        auto pkg =
-            std::make_unique<common::model::package>(c->using_namespace());
-        pkg->set_name(*it);
-        auto ns = common::model::path(parent_path.begin(), it);
-        // ns.pop_back();
-        pkg->set_namespace(ns);
-        pkg->set_id(common::to_id(pkg->full_name(false)));
-
-        add_package_fs(ns, std::move(pkg));
-    }
-
-    const auto base_name = c->name();
-    const auto full_name = c->full_name(false);
-    const auto id = c->id();
-    auto &cc = *c;
-
-    if (add_element(parent_path, std::move(c))) {
-        concepts_.push_back(std::ref(cc));
-        return true;
-    }
-
-    LOG_WARN("Cannot add class {} with id {} due to: {}", base_name, id);
-
-    return false;
+    return add_element(ns, std::move(p));
 }
 
 void diagram::get_parents(
@@ -456,7 +111,7 @@ void diagram::get_parents(
     bool found_new{false};
     for (const auto &parent : parents) {
         for (const auto &pp : parent.get().parents()) {
-            auto p = get_class(pp.id());
+            auto p = find<class_>(pp.id());
 
             if (p.has_value()) {
                 auto [it, found] = parents.emplace(std::ref(p.value()));
@@ -474,13 +129,19 @@ void diagram::get_parents(
 bool diagram::has_element(
     clanguml::common::model::diagram_element::id_t id) const
 {
-    const auto has_class = std::any_of(classes_.begin(), classes_.end(),
+    const auto has_class = std::any_of(classes().begin(), classes().end(),
         [id](const auto &c) { return c.get().id() == id; });
 
     if (has_class)
         return true;
 
-    return std::any_of(enums_.begin(), enums_.end(),
+    const auto has_concept = std::any_of(classes().begin(), classes().end(),
+        [id](const auto &c) { return c.get().id() == id; });
+
+    if (has_concept)
+        return true;
+
+    return std::any_of(enums().begin(), enums().end(),
         [id](const auto &c) { return c.get().id() == id; });
 }
 
@@ -489,18 +150,18 @@ std::string diagram::to_alias(
 {
     LOG_DBG("Looking for alias for {}", id);
 
-    for (const auto &c : classes_) {
+    for (const auto &c : classes()) {
         if (c.get().id() == id) {
             return c.get().alias();
         }
     }
 
-    for (const auto &e : enums_) {
+    for (const auto &e : enums()) {
         if (e.get().id() == id)
             return e.get().alias();
     }
 
-    for (const auto &c : concepts_) {
+    for (const auto &c : concepts()) {
         if (c.get().id() == id)
             return c.get().alias();
     }
diff --git a/src/class_diagram/model/diagram.h b/src/class_diagram/model/diagram.h
index 1d566ac7..47b42602 100644
--- a/src/class_diagram/model/diagram.h
+++ b/src/class_diagram/model/diagram.h
@@ -19,6 +19,7 @@
 
 #include "class.h"
 #include "common/model/diagram.h"
+#include "common/model/element_view.h"
 #include "common/model/nested_trait.h"
 #include "common/model/package.h"
 #include "common/types.h"
@@ -34,6 +35,7 @@ namespace clanguml::class_diagram::model {
 using common::opt_ref;
 using common::model::diagram_element;
 using common::model::diagram_t;
+using common::model::element_view;
 using common::model::path;
 using common::model::path_type;
 
@@ -41,7 +43,11 @@ using nested_trait_ns =
     clanguml::common::model::nested_trait<clanguml::common::model::element,
         clanguml::common::model::namespace_>;
 
-class diagram : public common::model::diagram::diagram, public nested_trait_ns {
+class diagram : public common::model::diagram::diagram,
+                public element_view<class_>,
+                public element_view<enum_>,
+                public element_view<concept_>,
+                public nested_trait_ns {
 public:
     diagram() = default;
 
@@ -62,32 +68,23 @@ public:
 
     const common::reference_vector<concept_> &concepts() const;
 
-    bool has_class(const class_ &c) const;
+    template <typename ElementT> bool contains(const ElementT &e);
 
-    bool has_enum(const enum_ &e) const;
+    template <typename ElementT>
+    opt_ref<ElementT> find(const std::string &name) const;
 
-    bool has_concept(const concept_ &e) const;
+    template <typename ElementT>
+    opt_ref<ElementT> find(diagram_element::id_t id) const;
 
-    opt_ref<class_> get_class(const std::string &name) const;
+    template <typename ElementT>
+    bool add(const path &parent_path, std::unique_ptr<ElementT> &&e)
+    {
+        if (parent_path.type() == common::model::path_type::kNamespace) {
+            return add_with_namespace_path(std::move(e));
+        }
 
-    opt_ref<class_> get_class(diagram_element::id_t id) const;
-
-    opt_ref<enum_> get_enum(const std::string &name) const;
-
-    opt_ref<enum_> get_enum(diagram_element::id_t id) const;
-
-    opt_ref<concept_> get_concept(const std::string &name) const;
-
-    opt_ref<concept_> get_concept(diagram_element::id_t id) const;
-
-    bool add_class(const path &parent_path, std::unique_ptr<class_> &&c);
-
-    bool add_enum(const path &parent_path, std::unique_ptr<enum_> &&e);
-
-    bool add_concept(const path &parent_path, std::unique_ptr<concept_> &&e);
-
-    bool add_package(
-        const path &parent_path, std::unique_ptr<common::model::package> &&p);
+        return add_with_filesystem_path(parent_path, std::move(e));
+    }
 
     std::string to_alias(diagram_element::id_t id) const;
 
@@ -100,28 +97,148 @@ public:
     inja::json context() const override;
 
 private:
-    bool add_class_ns(std::unique_ptr<class_> &&c);
-    bool add_class_fs(
-        const common::model::path &parent_path, std::unique_ptr<class_> &&c);
+    template <typename ElementT>
+    bool add_with_namespace_path(std::unique_ptr<ElementT> &&e);
 
-    bool add_enum_ns(std::unique_ptr<enum_> &&c);
-    bool add_enum_fs(
-        const common::model::path &parent_path, std::unique_ptr<enum_> &&c);
-
-    bool add_package_ns(std::unique_ptr<common::model::package> &&p);
-    bool add_package_fs(const common::model::path &parent_path,
-        std::unique_ptr<common::model::package> &&p);
-
-    bool add_concept_ns(std::unique_ptr<concept_> &&p);
-    bool add_concept_fs(
-        const common::model::path &parent_path, std::unique_ptr<concept_> &&p);
-
-    common::reference_vector<class_> classes_;
-
-    common::reference_vector<enum_> enums_;
-
-    common::reference_vector<concept_> concepts_;
+    template <typename ElementT>
+    bool add_with_filesystem_path(
+        const common::model::path &parent_path, std::unique_ptr<ElementT> &&e);
 };
+
+template <typename ElementT> bool diagram::contains(const ElementT &element)
+{
+    return std::any_of(element_view<ElementT>::view().cbegin(),
+        element_view<ElementT>::view().cend(),
+        [&element](
+            const auto &element_opt) { return element_opt.get() == element; });
+}
+
+template <typename ElementT>
+bool diagram::add_with_namespace_path(std::unique_ptr<ElementT> &&e)
+{
+    const auto base_name = e->name();
+    const auto full_name = e->full_name(false);
+    const auto element_type = e->type_name();
+
+    LOG_DBG("Adding {}: {}::{}, {}", element_type,
+        e->get_namespace().to_string(), base_name, full_name);
+
+    if (util::contains(base_name, "::"))
+        throw std::runtime_error("Name cannot contain namespace: " + base_name);
+
+    if (util::contains(base_name, "*"))
+        throw std::runtime_error("Name cannot contain *: " + base_name);
+
+    const auto ns = e->get_relative_namespace();
+    auto name = base_name;
+    auto name_with_ns = e->name_and_ns();
+    auto name_and_ns = ns | name;
+    auto &e_ref = *e;
+    auto id = e_ref.id();
+
+    try {
+        if (!contains(e_ref)) {
+            if (add_element(ns, std::move(e)))
+                element_view<ElementT>::add(std::ref(e_ref));
+
+            const auto &el = get_element<ElementT>(name_and_ns).value();
+
+            if ((el.name() != name) || !(el.get_relative_namespace() == ns))
+                throw std::runtime_error(
+                    "Invalid element stored in the diagram tree");
+
+            LOG_DBG("Added {} {} ({} - [{}])", element_type, base_name,
+                full_name, id);
+
+            return true;
+        }
+    }
+    catch (const std::runtime_error &e) {
+        LOG_WARN("Cannot add {} {} with id {} due to: {}", element_type, name,
+            id, e.what());
+        return false;
+    }
+
+    LOG_DBG("{} {} ({} - [{}]) already in the model", element_type, base_name,
+        full_name, id);
+
+    return false;
+}
+
+template <typename ElementT>
+bool diagram::add_with_filesystem_path(
+    const common::model::path &parent_path, std::unique_ptr<ElementT> &&e)
+{
+    const auto element_type = e->type_name();
+
+    // Make sure all parent directories are already packages in the
+    // model
+    for (auto it = parent_path.begin(); it != parent_path.end(); it++) {
+        auto pkg =
+            std::make_unique<common::model::package>(e->using_namespace());
+        pkg->set_name(*it);
+        auto ns = common::model::path(parent_path.begin(), it);
+        // ns.pop_back();
+        pkg->set_namespace(ns);
+        pkg->set_id(common::to_id(pkg->full_name(false)));
+
+        add(ns, std::move(pkg));
+    }
+
+    const auto base_name = e->name();
+    const auto full_name = e->full_name(false);
+    const auto id = e->id();
+    auto &e_ref = *e;
+
+    if (add_element(parent_path, std::move(e))) {
+        element_view<ElementT>::add(std::ref(e_ref));
+        return true;
+    }
+
+    LOG_WARN(
+        "Cannot add {} {} with id {} due to: {}", element_type, base_name, id);
+
+    return false;
+}
+
+template <typename ElementT>
+opt_ref<ElementT> diagram::find(const std::string &name) const
+{
+    for (const auto &element : element_view<ElementT>::view()) {
+        const auto full_name = element.get().full_name(false);
+
+        if (full_name == name) {
+            return {element};
+        }
+    }
+
+    return {};
+}
+
+template <typename ElementT>
+opt_ref<ElementT> diagram::find(diagram_element::id_t id) const
+{
+    for (const auto &element : element_view<ElementT>::view()) {
+        if (element.get().id() == id) {
+            return {element};
+        }
+    }
+
+    return {};
+}
+
+//
+// Template method specialization pre-declarations...
+//
+template <>
+bool diagram::add_with_namespace_path<common::model::package>(
+    std::unique_ptr<common::model::package> &&p);
+
+template <>
+bool diagram::add_with_filesystem_path<common::model::package>(
+    const common::model::path &parent_path,
+    std::unique_ptr<common::model::package> &&p);
+
 } // namespace clanguml::class_diagram::model
 
 namespace clanguml::common::model {
diff --git a/src/class_diagram/visitor/translation_unit_visitor.cc b/src/class_diagram/visitor/translation_unit_visitor.cc
index 39d66b85..05c89c08 100644
--- a/src/class_diagram/visitor/translation_unit_visitor.cc
+++ b/src/class_diagram/visitor/translation_unit_visitor.cc
@@ -84,7 +84,7 @@ bool translation_unit_visitor::VisitNamespaceDecl(clang::NamespaceDecl *ns)
         }
 
         if (!p->skip()) {
-            diagram().add_package(package_path, std::move(p));
+            diagram().add(package_path, std::move(p));
         }
     }
 
@@ -140,8 +140,8 @@ bool translation_unit_visitor::VisitEnumDecl(clang::EnumDecl *enm)
         }
     }
 
-    if (id_opt && diagram_.get_class(*id_opt)) {
-        auto parent_class = diagram_.get_class(*id_opt);
+    if (id_opt && diagram().find<class_>(*id_opt)) {
+        auto parent_class = diagram().find<class_>(*id_opt);
 
         e.set_namespace(ns);
         e.set_name(parent_class.value().name() + "##" + enm->getNameAsString());
@@ -364,8 +364,8 @@ bool translation_unit_visitor::VisitRecordDecl(clang::RecordDecl *rec)
 
     id_mapper().add(rec->getID(), rec_id);
 
-    auto &record_model = diagram().get_class(rec_id).has_value()
-        ? *diagram().get_class(rec_id).get()
+    auto &record_model = diagram().find<class_>(rec_id).has_value()
+        ? *diagram().find<class_>(rec_id).get()
         : *record_ptr;
 
     if (rec->isCompleteDefinition() && !record_model.complete()) {
@@ -730,8 +730,8 @@ bool translation_unit_visitor::VisitCXXRecordDecl(clang::CXXRecordDecl *cls)
 
     id_mapper().add(cls->getID(), cls_id);
 
-    auto &class_model = diagram().get_class(cls_id).has_value()
-        ? *diagram().get_class(cls_id).get()
+    auto &class_model = diagram().find<class_>(cls_id).has_value()
+        ? *diagram().find<class_>(cls_id).get()
         : *c_ptr;
 
     if (cls->isCompleteDefinition() && !class_model.complete())
@@ -899,11 +899,11 @@ void translation_unit_visitor::process_record_parent(
         }
     }
 
-    if (id_opt && diagram_.get_class(*id_opt)) {
+    if (id_opt && diagram_.find<class_>(*id_opt)) {
         // Here we have 2 options, either:
         //  - the parent is a regular C++ class/struct
         //  - the parent is a class template declaration/specialization
-        auto parent_class = diagram_.get_class(*id_opt);
+        auto parent_class = diagram_.find<class_>(*id_opt);
 
         c.set_namespace(parent_ns);
         const auto cls_name = cls->getNameAsString();
@@ -2105,10 +2105,10 @@ void translation_unit_visitor::add_class(std::unique_ptr<class_> &&c)
         common::model::path p{file, common::model::path_type::kFilesystem};
         p.pop_back();
 
-        diagram().add_class(p, std::move(c));
+        diagram().add(p, std::move(c));
     }
     else {
-        diagram().add_class(c->path(), std::move(c));
+        diagram().add(c->path(), std::move(c));
     }
 }
 
@@ -2123,10 +2123,10 @@ void translation_unit_visitor::add_enum(std::unique_ptr<enum_> &&e)
         common::model::path p{file, common::model::path_type::kFilesystem};
         p.pop_back();
 
-        diagram().add_enum(p, std::move(e));
+        diagram().add(p, std::move(e));
     }
     else {
-        diagram().add_enum(e->path(), std::move(e));
+        diagram().add(e->path(), std::move(e));
     }
 }
 
@@ -2141,10 +2141,10 @@ void translation_unit_visitor::add_concept(std::unique_ptr<concept_> &&c)
         common::model::path p{file, common::model::path_type::kFilesystem};
         p.pop_back();
 
-        diagram().add_concept(p, std::move(c));
+        diagram().add(p, std::move(c));
     }
     else {
-        diagram().add_concept(c->path(), std::move(c));
+        diagram().add(c->path(), std::move(c));
     }
 }
 
diff --git a/src/common/model/diagram_filter.cc b/src/common/model/diagram_filter.cc
index 3ab7080f..27e5b026 100644
--- a/src/common/model/diagram_filter.cc
+++ b/src/common/model/diagram_filter.cc
@@ -61,21 +61,21 @@ template <>
 const clanguml::common::optional_ref<class_diagram::model::class_> get(
     const class_diagram::model::diagram &d, const std::string &full_name)
 {
-    return d.get_class(full_name);
+    return d.find<class_diagram::model::class_>(full_name);
 }
 
 template <>
 const clanguml::common::optional_ref<common::model::package> get(
     const package_diagram::model::diagram &d, const std::string &full_name)
 {
-    return d.get_package(full_name);
+    return d.find<package>(full_name);
 }
 
 template <>
 const clanguml::common::optional_ref<common::model::source_file> get(
     const include_diagram::model::diagram &d, const std::string &full_name)
 {
-    return d.get_file(full_name);
+    return d.find<source_file>(full_name);
 }
 
 template <>
@@ -259,7 +259,7 @@ tvl::value_t subclass_filter::match(const diagram &d, const element &e) const
     clanguml::common::reference_set<class_diagram::model::class_> parents;
 
     const auto &fn = e.full_name(false);
-    auto class_ref = cd.get_class(fn);
+    auto class_ref = cd.find<class_diagram::model::class_>(fn);
 
     if (!class_ref.has_value())
         return false;
@@ -308,7 +308,7 @@ tvl::value_t parents_filter::match(const diagram &d, const element &e) const
     clanguml::common::reference_set<class_diagram::model::class_> parents;
 
     for (const auto &child : children_) {
-        auto child_ref = cd.get_class(child);
+        auto child_ref = cd.find<class_diagram::model::class_>(child);
         if (!child_ref.has_value())
             continue;
         parents.emplace(child_ref.value());
@@ -370,8 +370,8 @@ tvl::value_t context_filter::match(const diagram &d, const element &e) const
     return tvl::any_of(context_.begin(), context_.end(),
         [&e, &d](const auto &context_root_name) {
             const auto &context_root =
-                static_cast<const class_diagram::model::diagram &>(d).get_class(
-                    context_root_name);
+                static_cast<const class_diagram::model::diagram &>(d)
+                    .find<class_diagram::model::class_>(context_root_name);
 
             if (context_root.has_value()) {
                 // This is a direct match to the context root
diff --git a/src/common/model/element_view.h b/src/common/model/element_view.h
new file mode 100644
index 00000000..3e124341
--- /dev/null
+++ b/src/common/model/element_view.h
@@ -0,0 +1,70 @@
+/**
+ * src/common/model/element_view.h
+ *
+ * Copyright (c) 2021-2023 Bartek Kryza <bkryza@gmail.com>
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#pragma once
+
+#include "common/types.h"
+
+namespace clanguml::common::model {
+
+/**
+ * Provides type based views over elements in a diagram.
+ *
+ * @tparam T Type of diagram element
+ */
+template <typename T> class element_view {
+public:
+    /**
+     * @brief Add reference to diagram element
+     *
+     * @param element Reference to diagram element of specific type
+     */
+    void add(std::reference_wrapper<T> element)
+    {
+        elements_.emplace_back(std::move(element));
+    }
+
+    /**
+     * @brief Get collection of reference to diagram elements
+     *
+     * @return
+     */
+    const reference_vector<T> &view() const { return elements_; }
+
+    /**
+     * @brief Get typed diagram element by id
+     * @param id Global id of a diagram element
+     *
+     * @return
+     */
+    common::optional_ref<T> get(
+        clanguml::common::model::diagram_element::id_t id) const
+    {
+        for (const auto &e : elements_) {
+            if (e.get().id() == id) {
+                return {e};
+            }
+        }
+
+        return {};
+    }
+
+private:
+    reference_vector<T> elements_;
+};
+
+} // namespace clanguml::common::model
\ No newline at end of file
diff --git a/src/include_diagram/model/diagram.cc b/src/include_diagram/model/diagram.cc
index cd2e71b5..3a723898 100644
--- a/src/include_diagram/model/diagram.cc
+++ b/src/include_diagram/model/diagram.cc
@@ -31,19 +31,19 @@ common::model::diagram_t diagram::type() const
 common::optional_ref<common::model::diagram_element> diagram::get(
     const std::string &full_name) const
 {
-    return get_file(full_name);
+    return find<source_file>(full_name);
 }
 
 common::optional_ref<common::model::diagram_element> diagram::get(
     const common::model::diagram_element::id_t id) const
 {
-    return get_file(id);
+    return find<source_file>(id);
 }
 
 void diagram::add_file(std::unique_ptr<common::model::source_file> &&f)
 {
     // Don't add the same file more than once
-    if (get_file(f->id()))
+    if (find<source_file>(f->id()))
         return;
 
     LOG_DBG("Adding source file: {}, {}", f->name(), f->fs_path().string());
@@ -53,7 +53,7 @@ void diagram::add_file(std::unique_ptr<common::model::source_file> &&f)
     assert(!ff.name().empty());
     assert(ff.id() != 0);
 
-    files_.emplace_back(ff);
+    element_view<source_file>::add(ff);
 
     auto p = ff.path();
 
@@ -89,34 +89,6 @@ void diagram::add_file(std::unique_ptr<common::model::source_file> &&f)
     add_element(p, std::move(f));
 }
 
-common::optional_ref<common::model::source_file> diagram::get_file(
-    const std::string &name) const
-{
-    // Convert the name to the OS preferred path
-    std::filesystem::path namePath{name};
-    namePath.make_preferred();
-
-    for (const auto &p : files_) {
-        if (p.get().full_name(false) == namePath.string()) {
-            return {p};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<common::model::source_file> diagram::get_file(
-    const common::model::diagram_element::id_t id) const
-{
-    for (const auto &p : files_) {
-        if (p.get().id() == id) {
-            return {p};
-        }
-    }
-
-    return {};
-}
-
 std::string diagram::to_alias(const std::string &full_name) const
 {
     LOG_DBG("Looking for alias for {}", full_name);
@@ -139,7 +111,7 @@ std::string diagram::to_alias(const std::string &full_name) const
 const common::reference_vector<common::model::source_file> &
 diagram::files() const
 {
-    return files_;
+    return element_view<source_file>::view();
 }
 
 common::optional_ref<clanguml::common::model::diagram_element>
diff --git a/src/include_diagram/model/diagram.h b/src/include_diagram/model/diagram.h
index 6aea9cc9..82d606f4 100644
--- a/src/include_diagram/model/diagram.h
+++ b/src/include_diagram/model/diagram.h
@@ -18,6 +18,7 @@
 #pragma once
 
 #include "common/model/diagram.h"
+#include "common/model/element_view.h"
 #include "common/model/package.h"
 #include "common/model/source_file.h"
 #include "common/types.h"
@@ -27,9 +28,13 @@
 
 namespace clanguml::include_diagram::model {
 
+using clanguml::common::opt_ref;
+using clanguml::common::model::diagram_element;
+using clanguml::common::model::source_file;
+
 class diagram : public clanguml::common::model::diagram,
-                public clanguml::common::model::nested_trait<
-                    clanguml::common::model::source_file,
+                public clanguml::common::model::element_view<source_file>,
+                public clanguml::common::model::nested_trait<source_file,
                     clanguml::common::model::filesystem_path> {
 public:
     diagram() = default;
@@ -41,33 +46,58 @@ public:
 
     common::model::diagram_t type() const override;
 
-    common::optional_ref<common::model::diagram_element> get(
-        const std::string &full_name) const override;
+    opt_ref<diagram_element> get(const std::string &full_name) const override;
 
-    common::optional_ref<common::model::diagram_element> get(
-        common::model::diagram_element::id_t id) const override;
+    opt_ref<diagram_element> get(diagram_element::id_t id) const override;
 
     void add_file(std::unique_ptr<common::model::source_file> &&f);
 
-    common::optional_ref<common::model::source_file> get_file(
-        const std::string &name) const;
+    template <typename ElementT>
+    opt_ref<ElementT> find(const std::string &name) const;
 
-    common::optional_ref<common::model::source_file> get_file(
-        common::model::diagram_element::id_t id) const;
+    template <typename ElementT>
+    opt_ref<ElementT> find(diagram_element::id_t id) const;
 
     std::string to_alias(const std::string &full_name) const;
 
-    const common::reference_vector<common::model::source_file> &files() const;
+    const common::reference_vector<source_file> &files() const;
 
-    common::optional_ref<clanguml::common::model::diagram_element>
-    get_with_namespace(const std::string &name,
+    opt_ref<diagram_element> get_with_namespace(const std::string &name,
         const common::model::namespace_ &ns) const override;
 
     inja::json context() const override;
-
-private:
-    common::reference_vector<common::model::source_file> files_;
 };
+
+template <typename ElementT>
+opt_ref<ElementT> diagram::find(const std::string &name) const
+{
+    // Convert the name to the OS preferred path
+    std::filesystem::path namePath{name};
+    namePath.make_preferred();
+
+    for (const auto &element : element_view<ElementT>::view()) {
+        const auto full_name = element.get().full_name(false);
+
+        if (full_name == namePath.string()) {
+            return {element};
+        }
+    }
+
+    return {};
+}
+
+template <typename ElementT>
+opt_ref<ElementT> diagram::find(diagram_element::id_t id) const
+{
+    for (const auto &element : element_view<ElementT>::view()) {
+        if (element.get().id() == id) {
+            return {element};
+        }
+    }
+
+    return {};
+}
+
 } // namespace clanguml::include_diagram::model
 
 namespace clanguml::common::model {
diff --git a/src/package_diagram/model/diagram.cc b/src/package_diagram/model/diagram.cc
index dfe64537..b8f25258 100644
--- a/src/package_diagram/model/diagram.cc
+++ b/src/package_diagram/model/diagram.cc
@@ -31,75 +31,13 @@ common::model::diagram_t diagram::type() const
 const common::reference_vector<clanguml::common::model::package> &
 diagram::packages() const
 {
-    return packages_;
-}
-
-void diagram::add_package(std::unique_ptr<common::model::package> &&p)
-{
-    LOG_DBG(
-        "Adding package: {}, {}, [{}]", p->name(), p->full_name(true), p->id());
-
-    auto ns = p->get_relative_namespace();
-
-    packages_.emplace_back(*p);
-
-    add_element(ns, std::move(p));
-}
-
-void diagram::add_package_fs(const common::model::path &parent_path,
-    std::unique_ptr<common::model::package> &&p)
-{
-    LOG_DBG("Adding package: {}, {}", p->name(), p->full_name(true));
-
-    // Make sure all parent directories are already packages in the
-    // model
-    for (auto it = parent_path.begin(); it != parent_path.end(); it++) {
-        auto pkg =
-            std::make_unique<common::model::package>(p->using_namespace());
-        pkg->set_name(*it);
-        auto ns = common::model::path(parent_path.begin(), it);
-        // ns.pop_back();
-        pkg->set_namespace(ns);
-        pkg->set_id(common::to_id(pkg->full_name(false)));
-
-        add_package_fs(ns, std::move(pkg));
-    }
-
-    auto pp = std::ref(*p);
-    if (add_element(parent_path, std::move(p))) {
-        packages_.emplace_back(pp);
-    }
-}
-
-common::optional_ref<common::model::package> diagram::get_package(
-    const std::string &name) const
-{
-    for (const auto &p : packages_) {
-        auto p_full_name = p.get().full_name(false);
-        if (p_full_name == name) {
-            return {p};
-        }
-    }
-
-    return {};
-}
-
-common::optional_ref<common::model::package> diagram::get_package(
-    const clanguml::common::model::diagram_element::id_t id) const
-{
-    for (const auto &p : packages_) {
-        if (p.get().id() == id) {
-            return {p};
-        }
-    }
-
-    return {};
+    return element_view<package>::view();
 }
 
 common::optional_ref<clanguml::common::model::diagram_element> diagram::get(
     const std::string &full_name) const
 {
-    return get_package(full_name);
+    return find<package>(full_name);
 }
 
 common::optional_ref<clanguml::common::model::diagram_element> diagram::get(
@@ -107,7 +45,7 @@ common::optional_ref<clanguml::common::model::diagram_element> diagram::get(
 {
     LOG_DBG("Looking for package with id {}", id);
 
-    return get_package(id);
+    return find<package>(id);
 }
 
 std::string diagram::to_alias(
@@ -115,10 +53,9 @@ std::string diagram::to_alias(
 {
     LOG_DBG("Looking for alias for {}", id);
 
-    for (const auto &p : packages_) {
-        if (p.get().id() == id)
-            return p.get().alias();
-    }
+    auto p = find<package>(id);
+    if (p.has_value() && p.value().id() == id)
+        return p.value().alias();
 
     return {};
 }
diff --git a/src/package_diagram/model/diagram.h b/src/package_diagram/model/diagram.h
index 4c7cf528..1a4aadd2 100644
--- a/src/package_diagram/model/diagram.h
+++ b/src/package_diagram/model/diagram.h
@@ -18,6 +18,7 @@
 #pragma once
 
 #include "common/model/diagram.h"
+#include "common/model/element_view.h"
 #include "common/model/package.h"
 
 #include <string>
@@ -25,7 +26,13 @@
 
 namespace clanguml::package_diagram::model {
 
+using clanguml::common::opt_ref;
+using clanguml::common::model::diagram_element;
+using clanguml::common::model::package;
+using clanguml::common::model::path;
+
 class diagram : public clanguml::common::model::diagram,
+                public clanguml::common::model::element_view<package>,
                 public clanguml::common::model::nested_trait<
                     clanguml::common::model::element,
                     clanguml::common::model::namespace_> {
@@ -39,34 +46,109 @@ public:
 
     common::model::diagram_t type() const override;
 
-    const common::reference_vector<clanguml::common::model::package> &
-    packages() const;
+    const common::reference_vector<package> &packages() const;
 
-    common::optional_ref<clanguml::common::model::diagram_element> get(
-        const std::string &full_name) const override;
+    opt_ref<diagram_element> get(const std::string &full_name) const override;
 
-    common::optional_ref<clanguml::common::model::diagram_element> get(
-        clanguml::common::model::diagram_element::id_t id) const override;
+    opt_ref<diagram_element> get(diagram_element::id_t id) const override;
 
-    common::optional_ref<clanguml::common::model::package> get_package(
-        const std::string &name) const;
+    template <typename ElementT>
+    opt_ref<ElementT> find(const std::string &name) const;
 
-    common::optional_ref<common::model::package> get_package(
-        clanguml::common::model::diagram_element::id_t id) const;
+    template <typename ElementT>
+    opt_ref<ElementT> find(diagram_element::id_t id) const;
 
-    void add_package(std::unique_ptr<common::model::package> &&p);
+    template <typename ElementT>
+    bool add(const path &parent_path, std::unique_ptr<ElementT> &&e)
+    {
+        if (parent_path.type() == common::model::path_type::kNamespace) {
+            return add_with_namespace_path(std::move(e));
+        }
 
-    void add_package_fs(const common::model::path &parent_path,
-        std::unique_ptr<common::model::package> &&p);
+        return add_with_filesystem_path(parent_path, std::move(e));
+    }
 
-    std::string to_alias(
-        clanguml::common::model::diagram_element::id_t /*id*/) const;
+    template <typename ElementT>
+    bool add_with_namespace_path(std::unique_ptr<ElementT> &&e);
+
+    template <typename ElementT>
+    bool add_with_filesystem_path(
+        const common::model::path &parent_path, std::unique_ptr<ElementT> &&e);
+
+    std::string to_alias(diagram_element::id_t /*id*/) const;
 
     inja::json context() const override;
-
-private:
-    common::reference_vector<clanguml::common::model::package> packages_;
 };
+
+template <typename ElementT>
+opt_ref<ElementT> diagram::find(const std::string &name) const
+{
+    for (const auto &element : element_view<ElementT>::view()) {
+        const auto full_name = element.get().full_name(false);
+
+        if (full_name == name) {
+            return {element};
+        }
+    }
+
+    return {};
+}
+
+template <typename ElementT>
+opt_ref<ElementT> diagram::find(diagram_element::id_t id) const
+{
+    for (const auto &element : element_view<ElementT>::view()) {
+        if (element.get().id() == id) {
+            return {element};
+        }
+    }
+
+    return {};
+}
+
+template <typename ElementT>
+bool diagram::add_with_namespace_path(std::unique_ptr<ElementT> &&p)
+{
+    LOG_DBG(
+        "Adding package: {}, {}, [{}]", p->name(), p->full_name(true), p->id());
+
+    auto ns = p->get_relative_namespace();
+    auto p_ref = std::ref(*p);
+
+    auto res = add_element(ns, std::move(p));
+    if (res)
+        element_view<ElementT>::add(p_ref);
+
+    return res;
+}
+
+template <typename ElementT>
+bool diagram::add_with_filesystem_path(
+    const common::model::path &parent_path, std::unique_ptr<ElementT> &&p)
+{
+    LOG_DBG("Adding package: {}, {}", p->name(), p->full_name(true));
+
+    // Make sure all parent directories are already packages in the
+    // model
+    for (auto it = parent_path.begin(); it != parent_path.end(); it++) {
+        auto pkg =
+            std::make_unique<common::model::package>(p->using_namespace());
+        pkg->set_name(*it);
+        auto ns = common::model::path(parent_path.begin(), it);
+        pkg->set_namespace(ns);
+        pkg->set_id(common::to_id(pkg->full_name(false)));
+
+        add_with_filesystem_path(ns, std::move(pkg));
+    }
+
+    auto pp = std::ref(*p);
+    auto res = add_element(parent_path, std::move(p));
+    if (res)
+        element_view<ElementT>::add(pp);
+
+    return res;
+}
+
 } // namespace clanguml::package_diagram::model
 
 namespace clanguml::common::model {
diff --git a/src/package_diagram/visitor/translation_unit_visitor.cc b/src/package_diagram/visitor/translation_unit_visitor.cc
index 5456cbe6..ae706c92 100644
--- a/src/package_diagram/visitor/translation_unit_visitor.cc
+++ b/src/package_diagram/visitor/translation_unit_visitor.cc
@@ -93,7 +93,7 @@ bool translation_unit_visitor::VisitNamespaceDecl(clang::NamespaceDecl *ns)
         }
 
         if (!p->skip()) {
-            diagram().add_package(std::move(p));
+            diagram().add(p->path(), std::move(p));
         }
     }
 
@@ -222,7 +222,7 @@ void translation_unit_visitor::add_relationships(
         pkg->set_name(pkg_name);
         pkg->set_id(get_package_id(cls));
 
-        diagram().add_package_fs(parent_path, std::move(pkg));
+        diagram().add(parent_path, std::move(pkg));
     }
 
     auto current_package_id = get_package_id(cls);