From 3b11c4aec4410b8fd406fa98192fb4a2a0ba96a4 Mon Sep 17 00:00:00 2001
From: heromyth <bitworld@qq.com>
Date: Wed, 26 Feb 2020 16:14:12 +0800
Subject: [PATCH] Add a constuction handler

---
 example/postconstructorpredestructor/app.d | 10 ++++++++--
 source/poodinis/factory.d                  | 10 ++++++++++
 source/poodinis/registration.d             |  7 ++++++-
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/example/postconstructorpredestructor/app.d b/example/postconstructorpredestructor/app.d
index f72f3dc..fb7c963 100644
--- a/example/postconstructorpredestructor/app.d
+++ b/example/postconstructorpredestructor/app.d
@@ -42,8 +42,14 @@ class AClass {
 
 public void main() {
 	auto container = new shared DependencyContainer();
-	container.register!ADependency;
-	container.register!AClass;
+	container.register!(ADependency).onConstructed((Object obj) {
+		writeln("ADependency constructed");
+	});
+
+	container.register!(AClass).onConstructed((Object obj) {
+		writeln("AClass constructed");
+	});
+
 	auto instance = container.resolve!AClass; // Will cause the post constructor to be called.
 	container.removeRegistration!AClass; // Will cause the pre destructor to be called.
 
diff --git a/source/poodinis/factory.d b/source/poodinis/factory.d
index aae3f52..5d80d5b 100644
--- a/source/poodinis/factory.d
+++ b/source/poodinis/factory.d
@@ -22,6 +22,7 @@ import std.stdio;
 
 alias CreatesSingleton = Flag!"CreatesSingleton";
 alias InstanceFactoryMethod = Object delegate();
+alias InstanceEventHandler = void delegate(Object instance);
 
 class InstanceCreationException : Exception {
     this(string message, string file = __FILE__, size_t line = __LINE__) {
@@ -39,6 +40,7 @@ struct InstanceFactoryParameters {
 class InstanceFactory {
     private Object instance = null;
     private InstanceFactoryParameters _factoryParameters;
+    private InstanceEventHandler _constructionHandler;
 
     this() {
         factoryParameters = InstanceFactoryParameters();
@@ -75,9 +77,17 @@ class InstanceFactory {
         }
 
         instance = _factoryParameters.factoryMethod();
+        if(_constructionHandler !is null) {
+            _constructionHandler(instance);
+        }
+
         return instance;
     }
 
+    void onConstructed(InstanceEventHandler handler) {
+        _constructionHandler = handler;
+    }
+
     private void printDebugUseExistingInstance() {
         if (_factoryParameters.instanceType !is null) {
             writeln(format("DEBUG: Existing instance returned of type %s", _factoryParameters.instanceType.toString()));
diff --git a/source/poodinis/registration.d b/source/poodinis/registration.d
index cfaca3b..1a4970b 100644
--- a/source/poodinis/registration.d
+++ b/source/poodinis/registration.d
@@ -60,7 +60,6 @@ class Registration {
             return linkedRegistration.getInstance(context);
         }
 
-
         if (instanceFactory is null) {
             throw new InstanceCreationException("No instance factory defined for registration of type " ~ registeredType.toString());
         }
@@ -72,6 +71,12 @@ class Registration {
         this.linkedRegistration = registration;
         return this;
     }
+
+    Registration onConstructed(InstanceEventHandler handler) {
+        if(instanceFactory !is null)
+            instanceFactory.onConstructed(handler);
+        return this;
+    }
 }
 
 /**