From e22849eb32e07d77feb98df86907b939d76a196f Mon Sep 17 00:00:00 2001
From: Bartek Kryza <bkryza@gmail.com>
Date: Wed, 23 Mar 2022 22:56:59 +0100
Subject: [PATCH] Added alias() template function for resolving PlantUML
 aliases

---
 src/common/generators/plantuml/generator.h | 29 ++++++++++++++++++----
 tests/t00020/.clang-uml                    |  4 +--
 tests/t30001/.clang-uml                    |  2 +-
 3 files changed, 27 insertions(+), 8 deletions(-)

diff --git a/src/common/generators/plantuml/generator.h b/src/common/generators/plantuml/generator.h
index 15507af2..29aebf4e 100644
--- a/src/common/generators/plantuml/generator.h
+++ b/src/common/generators/plantuml/generator.h
@@ -168,16 +168,19 @@ void generator<C, D>::generate_plantuml_directives(
 {
     using common::model::namespace_;
 
-    for (const auto &b : directives) {
-        std::string note{b};
+    for (const auto &d : directives) {
+        // Render the directive with template engine first
+        std::string directive{env().render(std::string_view{d}, context())};
+
+        // Now search for alias @A() directives in the text
         std::tuple<std::string, size_t, size_t> alias_match;
-        while (util::find_element_alias(note, alias_match)) {
+        while (util::find_element_alias(directive, alias_match)) {
             auto alias = m_model.to_alias(
                 m_config.using_namespace().relative(std::get<0>(alias_match)));
-            note.replace(
+            directive.replace(
                 std::get<1>(alias_match), std::get<2>(alias_match), alias);
         }
-        ostr << note << '\n';
+        ostr << directive << '\n';
     }
 }
 
@@ -268,7 +271,9 @@ template <typename C, typename D> void generator<C, D>::init_context()
 
 template <typename C, typename D> void generator<C, D>::init_env()
 {
+    //
     // Add basic string functions to inja environment
+    //
     m_env.add_callback("empty", 1, [](inja::Arguments &args) {
         return args.at(0)->get<std::string>().empty();
     });
@@ -300,6 +305,20 @@ template <typename C, typename D> void generator<C, D>::init_env()
         return util::split(
             args[0]->get<std::string>(), args[1]->get<std::string>());
     });
+
+    //
+    // Add PlantUML specific functions
+    //
+
+    // Convert C++ entity to PlantUML alias, e.g.
+    //   "note left of {{ alias("ClassA") }}: This is a note"
+    // is equivalent to the old syntax:
+    //   "note left of @A(ClassA): This is a note"
+    m_env.add_callback("alias", 1, [this](inja::Arguments &args) {
+        auto alias_match = args[0]->get<std::string>();
+        return m_model.to_alias(
+            m_config.using_namespace().relative(alias_match));
+    });
 }
 
 }
diff --git a/tests/t00020/.clang-uml b/tests/t00020/.clang-uml
index fcd04dcd..b24214be 100644
--- a/tests/t00020/.clang-uml
+++ b/tests/t00020/.clang-uml
@@ -14,5 +14,5 @@ diagrams:
       after:
         - '@A(ProductA1) <.. @A(Factory1)'
         - '@A(ProductB1) <.. @A(Factory1)'
-        - '@A(ProductA2) <.. @A(Factory2)'
-        - '@A(ProductB2) <.. @A(Factory2)'
+        - '{{ alias("ProductA2") }} <.. {{ alias("Factory2") }}'
+        - '{{ alias("ProductB2") }} <.. {{ alias("Factory2") }}'
diff --git a/tests/t30001/.clang-uml b/tests/t30001/.clang-uml
index 1e5f3625..d519c601 100644
--- a/tests/t30001/.clang-uml
+++ b/tests/t30001/.clang-uml
@@ -17,4 +17,4 @@ diagrams:
       before:
         - "' t30001 test package diagram"
       after:
-        - "note right of @A(A::AA::AAA): A AAA note..."
\ No newline at end of file
+        - 'note right of {{ alias("A::AA::AAA") }}: A AAA note...'
\ No newline at end of file