From 5bd025099ffed5eddda11bbbbb080939b82e41e7 Mon Sep 17 00:00:00 2001
From: Cosmin <albulescu.cosmin@gmail.com>
Date: Wed, 5 Feb 2020 01:52:38 +0200
Subject: [PATCH] Apply to struct without connect

---
 container.go | 127 ++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 90 insertions(+), 37 deletions(-)

diff --git a/container.go b/container.go
index d8df5f8..91cfdf9 100644
--- a/container.go
+++ b/container.go
@@ -57,41 +57,9 @@ func New() Container {
 	}
 }
 
-// Connect a component, optionally identified by id.
-func (container Container) Connect(val interface{}, id ...string) {
-	ptr := false
-	rv := reflect.ValueOf(val)
-	rt := rv.Type()
-	nam := ""
-	_, file, no, _ := runtime.Caller(container.callerSkip + 1)
-
-	if len(id) > 0 {
-		nam = id[0]
-	}
-
-	comp := component{
-		id:         nam,
-		value:      rv,
-		declaredAt: file + ":" + strconv.Itoa(no),
-	}
-
-	if rt.Kind() == reflect.Ptr {
-		rt = rt.Elem()
-		rv = rv.Elem()
-		comp.value = rv
-		ptr = true
-	}
-
-	if gr, ok := container.components[rt]; ok {
-		if comp, ok := gr.find(nam); ok {
-			panic(duplicateError{previous: comp})
-		}
-	}
+func dependinces(container Container, rt reflect.Type, rv reflect.Value) []dependency {
 
-	if rt.Kind() != reflect.Struct {
-		container.components[rt] = append(container.components[rt], comp)
-		return
-	}
+	dependinces := make([]dependency, 0)
 
 	for i := 0; i < rt.NumField(); i++ {
 		sf := rt.Field(i)
@@ -121,15 +89,17 @@ func (container Container) Connect(val interface{}, id ...string) {
 				impl = idAndImpl[1]
 			}
 
-			comp.dependencies = append(comp.dependencies, dependency{
+			dependinces = append(dependinces, dependency{
 				id:    id,
 				name:  sf.Name,
 				index: i,
 				typ:   depRt,
 				impl:  impl,
 			})
+
 		} else if (sf.Type.Kind() == reflect.Ptr || sf.Type.Kind() == reflect.Interface) && rv.Field(i).IsNil() {
-			panic(tagMissingError{field: sf})
+			// Is this required
+			// panic(tagMissingError{field: sf})
 		} else if sf.Type.Kind() == reflect.Struct {
 			// check forgotten tag only for struct.
 			if _, exist := container.components[sf.Type]; exist {
@@ -138,6 +108,47 @@ func (container Container) Connect(val interface{}, id ...string) {
 		}
 	}
 
+	return dependinces
+}
+
+// Connect a component, optionally identified by id.
+func (container Container) Connect(val interface{}, id ...string) {
+	ptr := false
+	rv := reflect.ValueOf(val)
+	rt := rv.Type()
+	nam := ""
+	_, file, no, _ := runtime.Caller(container.callerSkip + 1)
+
+	if len(id) > 0 {
+		nam = id[0]
+	}
+
+	comp := component{
+		id:         nam,
+		value:      rv,
+		declaredAt: file + ":" + strconv.Itoa(no),
+	}
+
+	if rt.Kind() == reflect.Ptr {
+		rt = rt.Elem()
+		rv = rv.Elem()
+		comp.value = rv
+		ptr = true
+	}
+
+	if gr, ok := container.components[rt]; ok {
+		if comp, ok := gr.find(nam); ok {
+			panic(duplicateError{previous: comp})
+		}
+	}
+
+	if rt.Kind() != reflect.Struct {
+		container.components[rt] = append(container.components[rt], comp)
+		return
+	}
+
+	comp.dependencies = dependinces(container, rt, rv)
+
 	if len(comp.dependencies) != 0 && !ptr {
 		panic(incompletedError{})
 	}
@@ -173,6 +184,18 @@ func (container Container) Resolve(out interface{}, id ...string) {
 			panic(notAddressableError{id: nam, paramType: rt, component: comp})
 		}
 	} else {
+
+		if rt.Kind() == reflect.Interface {
+			for _, group := range container.components {
+				if v, e := group.find(nam); e {
+					if v.value.Addr().Type().Implements(rt) {
+						reflect.Indirect(rv).Set(v.value)
+						return
+					}
+				}
+			}
+		}
+
 		if gr, ok := container.components[rt]; ok {
 			rv.Set(gr.get(nam).value)
 			return
@@ -183,7 +206,37 @@ func (container Container) Resolve(out interface{}, id ...string) {
 }
 
 // Apply wiring to all components.
-func (container Container) Apply() {
+func (container Container) Apply(to ...interface{}) {
+
+	if len(to) > 0 {
+
+		rv := reflect.ValueOf(to[0])
+		rt := rv.Type()
+		_, file, no, _ := runtime.Caller(container.callerSkip + 1)
+
+		comp := component{
+			id:         "",
+			value:      rv,
+			declaredAt: file + ":" + strconv.Itoa(no),
+		}
+
+		if rt.Kind() == reflect.Ptr {
+			rt = rt.Elem()
+			rv = rv.Elem()
+			comp.value = rv
+		}
+
+		comp.dependencies = dependinces(
+			container,
+			rt,
+			rv,
+		)
+
+		container.fill(comp)
+
+		return
+	}
+
 	for _, gr := range container.components {
 		for _, comp := range gr {
 			container.fill(comp)