From c65c85b08b8b5b88c8586fd4075dc73f8f9ddc5b Mon Sep 17 00:00:00 2001
From: Vasiliy Tolstov <v.tolstov@unistack.org>
Date: Fri, 18 Dec 2020 03:40:34 +0300
Subject: [PATCH] before/after config stuff handled by implementations

Signed-off-by: Vasiliy Tolstov <v.tolstov@unistack.org>
---
 env.go | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/env.go b/env.go
index f4eb680..f9603a1 100644
--- a/env.go
+++ b/env.go
@@ -30,12 +30,24 @@ func (c *envConfig) Init(opts ...config.Option) error {
 }
 
 func (c *envConfig) Load(ctx context.Context) error {
+	for _, fn := range c.opts.BeforeLoad {
+		if err := fn(ctx, c); err != nil {
+			return err
+		}
+	}
+
 	valueOf := reflect.ValueOf(c.opts.Struct)
 
 	if err := c.fillValues(ctx, valueOf); err != nil {
 		return err
 	}
 
+	for _, fn := range c.opts.AfterLoad {
+		if err := fn(ctx, c); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }
 
@@ -219,6 +231,18 @@ func (c *envConfig) fillValues(ctx context.Context, valueOf reflect.Value) error
 }
 
 func (c *envConfig) Save(ctx context.Context) error {
+	for _, fn := range c.opts.BeforeSave {
+		if err := fn(ctx, c); err != nil {
+			return err
+		}
+	}
+
+	for _, fn := range c.opts.AfterSave {
+		if err := fn(ctx, c); err != nil {
+			return err
+		}
+	}
+
 	return nil
 }