Add try_get_activation_factory overloads with class name (#769)

Author: ChrisGuzak

strings/base_activation.h

@@ -400,10 +400,9 @@ namespace winrt::impl
         return factory.call(static_cast<CastType>(callback));
     }
 
-    template <typename Class, typename Interface = Windows::Foundation::IActivationFactory>
-    com_ref<Interface> try_get_activation_factory(hresult_error* exception = nullptr) noexcept
+    template <typename Interface = Windows::Foundation::IActivationFactory>
+    com_ref<Interface> try_get_activation_factory(param::hstring const& name, hresult_error* exception = nullptr) noexcept
     {
-        param::hstring const name{ name_of<Class>() };
         void* result{};
         hresult const hr = get_runtime_activation_factory<Interface>(name, &result);
 
@@ -463,7 +462,7 @@ WINRT_EXPORT namespace winrt
     {
         // Normally, the callback avoids having to return a ref-counted object and the resulting AddRef/Release bump.
         // In this case we do want a unique reference, so we use the lambda to return one and thus produce an
-        // AddRef'd object that is returned to the caller. 
+        // AddRef'd object that is returned to the caller.
         return impl::call_factory<Class, Interface>([](auto&& factory)
         {
             return factory;
@@ -473,13 +472,25 @@ WINRT_EXPORT namespace winrt
     template <typename Class, typename Interface = Windows::Foundation::IActivationFactory>
     auto try_get_activation_factory() noexcept
     {
-        return impl::try_get_activation_factory<Class, Interface>();
+        return impl::try_get_activation_factory<Interface>(name_of<Class>());
     }
 
     template <typename Class, typename Interface = Windows::Foundation::IActivationFactory>
     auto try_get_activation_factory(hresult_error& exception) noexcept
     {
-        return impl::try_get_activation_factory<Class, Interface>(&exception);
+        return impl::try_get_activation_factory<Interface>(name_of<Class>(), &exception);
+    }
+
+    template <typename Interface = Windows::Foundation::IActivationFactory>
+    auto try_get_activation_factory(param::hstring const& name) noexcept
+    {
+        return impl::try_get_activation_factory<Interface>(name);
+    }
+
+    template <typename Interface = Windows::Foundation::IActivationFactory>
+    auto try_get_activation_factory(param::hstring const& name, hresult_error& exception) noexcept
+    {
+        return impl::try_get_activation_factory<Interface>(name, &exception);
     }
 
     inline void clear_factory_cache() noexcept

test/old_tests/UnitTests/get_activation_factory.cpp

@@ -26,16 +26,17 @@ TEST_CASE("get_activation_factory")
     REQUIRE_THROWS_AS(get_activation_factory(L"Composable.DoesNotExist"), hresult_class_not_registered);
 }
 
-TEST_CASE("try_get_activation_factory")
+// Used to test whether the IRestrictedErrorInfo was left on the thread
+auto get_error_info()
 {
-    // Used to test whether the IRestrictedErrorInfo was left on the thread
-    auto get_error_info = []
-    {
-        com_ptr<IErrorInfo> info;
-        GetErrorInfo(0, info.put());
-        return info.as<impl::IRestrictedErrorInfo>();
-    };
+    com_ptr<IErrorInfo> info;
+    GetErrorInfo(0, info.put());
+    return info.as<impl::IRestrictedErrorInfo>();
+}
 
+
+TEST_CASE("try_get_activation_factory")
+{
     // Try successfully
     {
         auto factory = try_get_activation_factory<Component::Errors>();
@@ -67,3 +68,37 @@ TEST_CASE("try_get_activation_factory")
         REQUIRE(e.code() == REGDB_E_CLASSNOTREG);
     }
 }
+
+TEST_CASE("try_get_activation_factory_with_names")
+{
+    // Try successfully
+    {
+        auto factory = try_get_activation_factory(winrt::name_of<Component::Errors>());
+        REQUIRE(factory != nullptr);
+        REQUIRE(get_error_info() == nullptr);
+    }
+
+    // Try unsuccessfully
+    {
+        auto factory = try_get_activation_factory(winrt::name_of<Component::IErrors>());
+        REQUIRE(factory == nullptr);
+        REQUIRE(get_error_info() == nullptr);
+    }
+
+    // Try successfully with error info
+    {
+        hresult_error e;
+        auto factory = try_get_activation_factory(winrt::name_of<Component::Errors>(), e);
+        REQUIRE(factory != nullptr);
+        REQUIRE(get_error_info() == nullptr);
+    }
+
+    // Try unsuccessfully with error info
+    {
+        hresult_error e;
+        auto factory = try_get_activation_factory(winrt::name_of<Component::IErrors>(), e);
+        REQUIRE(factory == nullptr);
+        REQUIRE(get_error_info() == nullptr);
+        REQUIRE(e.code() == REGDB_E_CLASSNOTREG);
+    }
+}