From 3e11ff1e92ce0ee71355ba8e93be01b37edd05f7 Mon Sep 17 00:00:00 2001
From: Mike Bierlee <m.bierlee@lostmoment.com>
Date: Fri, 3 Jul 2015 23:45:10 +0200
Subject: [PATCH] Add ability to assign new instance to autowired member
 regardless of registration scope

---
 source/poodinis/autowire.d   | 30 ++++++++++++++++++++++++++++--
 test/poodinis/autowiretest.d | 18 ++++++++++++++++++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/source/poodinis/autowire.d b/source/poodinis/autowire.d
index 71b1697..45b2df0 100644
--- a/source/poodinis/autowire.d
+++ b/source/poodinis/autowire.d
@@ -64,6 +64,21 @@ struct Autowire(QualifierType = UseMemberType) {
 	QualifierType qualifier;
 };
 
+/**
+ * UDA for annotating class members to be autowired with a new instance regardless of their registration scope.
+ *
+ * Examples:
+ *---
+ * class Car {
+ *     @Autowire
+ *     @AssignNewInstance
+ *     public Antenna antenna;
+ * }
+ *---
+ * antenna will always be assigned a new instance of class Antenna.
+ */
+struct AssignNewInstance {}
+
 private void printDebugAutowiredInstance(TypeInfo instanceType, void* instanceAddress) {
 	writeln(format("DEBUG: Autowiring members of [%s@%s]", instanceType, instanceAddress));
 }
@@ -105,6 +120,8 @@ private void autowireMember(string member, Type)(shared(DependencyContainer) con
 				if (__traits(getMember, instance, member) is null) {
 					alias MemberType = typeof(__traits(getMember, instance, member));
 
+					enum assignNewInstance = hasUDA!(__traits(getMember, instance, member), AssignNewInstance);
+
 					static if (isDynamicArray!MemberType) {
 						alias MemberElementType = ElementType!MemberType;
 						auto instances = container.resolveAll!MemberElementType;
@@ -120,12 +137,12 @@ private void autowireMember(string member, Type)(shared(DependencyContainer) con
 						MemberType qualifiedInstance;
 						static if (is(autowireAttribute == Autowire!T, T) && !is(autowireAttribute.qualifier == UseMemberType)) {
 							alias QualifierType = typeof(autowireAttribute.qualifier);
-							qualifiedInstance = container.resolve!(MemberType, QualifierType);
+							qualifiedInstance = createOrResolveInstance!(MemberType, QualifierType, assignNewInstance)(container);
 							debug(poodinisVerbose) {
 								qualifiedInstanceType = typeid(QualifierType);
 							}
 						} else {
-							qualifiedInstance = container.resolve!(MemberType);
+							qualifiedInstance = createOrResolveInstance!(MemberType, MemberType, assignNewInstance)(container);
 						}
 
 						__traits(getMember, instance, member) = qualifiedInstance;
@@ -142,6 +159,15 @@ private void autowireMember(string member, Type)(shared(DependencyContainer) con
 	}
 }
 
+private QualifierType createOrResolveInstance(MemberType, QualifierType, bool createNew)(shared(DependencyContainer) container) {
+	static if (createNew) {
+		auto instanceFactory = new NewInstanceScope(typeid(MemberType));
+		return cast(MemberType) instanceFactory.getInstance();
+	} else {
+		return container.resolve!(MemberType, QualifierType);
+	}
+}
+
 /**
  * Autowire the given instance using the globally available dependency container.
  *
diff --git a/test/poodinis/autowiretest.d b/test/poodinis/autowiretest.d
index bc5efae..93558bc 100644
--- a/test/poodinis/autowiretest.d
+++ b/test/poodinis/autowiretest.d
@@ -63,6 +63,11 @@ version(unittest) {
 		@Autowire
 		public InterfaceA[] components;
 	}
+	class ComponentCharlie {
+		@Autowire
+		@AssignNewInstance
+		public ComponentA componentA;
+	}
 
 	// Test autowiring concrete type to existing instance
 	unittest {
@@ -170,4 +175,17 @@ version(unittest) {
 
 		assert(lord.components.length == 2, "Dynamic array was not autowired");
 	}
+
+	// Test autowiring new instance of singleinstance registration with newInstance UDA
+	unittest {
+		shared(DependencyContainer) container = new DependencyContainer();
+		container.register!ComponentA;
+
+		auto regularComponentA = container.resolve!ComponentA;
+		auto charlie = new ComponentCharlie();
+
+		container.autowire(charlie);
+
+		assert(charlie.componentA !is regularComponentA, "Autowiring class with AssignNewInstance did not yield a different instance");
+	}
 }