From b0ccd579afd9228c47238904267c6f216e40491d Mon Sep 17 00:00:00 2001
From: "Gerasimos (Makis) Maropoulos" <kataras2006@hotmail.com>
Date: Sun, 10 Apr 2022 01:08:11 +0300
Subject: [PATCH] add a new _proposals folder and a silly idea

---
 .deepsource.toml              |  2 +-
 _proposals/generic_handler.md | 81 +++++++++++++++++++++++++++++++++++
 context/context.go            | 16 +++++--
 3 files changed, 94 insertions(+), 5 deletions(-)
 create mode 100644 _proposals/generic_handler.md

diff --git a/.deepsource.toml b/.deepsource.toml
index 17377110..b2c8a5ba 100644
--- a/.deepsource.toml
+++ b/.deepsource.toml
@@ -13,4 +13,4 @@ name = "go"
 enabled = true
 
   [analyzers.meta]
-  import_paths = ["github.com/kataras/iris"]
+  import_paths = ["github.com/kataras/iris/v12"]
diff --git a/_proposals/generic_handler.md b/_proposals/generic_handler.md
new file mode 100644
index 00000000..950b3643
--- /dev/null
+++ b/_proposals/generic_handler.md
@@ -0,0 +1,81 @@
+# Iris Handler with Generics support
+
+```go
+package x
+
+import (
+	"github.com/kataras/iris/v12/context"
+	"github.com/kataras/iris/v12/x/errors"
+)
+
+var ErrorHandler context.ErrorHandler = context.ErrorHandlerFunc(errors.InvalidArgument.Err)
+
+type (
+	Handler[Request any | *context.Context, Response any] func(Request) (Response, error)
+	HandlerWithCtx[Request any, Response any]             func(*context.Context, Request) (Response, error)
+)
+
+func HandleContext[Request any, Response any](handler HandlerWithCtx[Request, Response]) context.Handler {
+	return func(ctx *context.Context) {
+		var req Request
+		if err := ctx.ReadJSON(&req); err != nil {
+			errors.InvalidArgument.Details(ctx, "unable to parse body", err.Error())
+			return
+		}
+
+		resp, err := handler(ctx, req)
+		if err != nil {
+			ErrorHandler.HandleContextError(ctx, err)
+			return
+		}
+
+		if _, err = ctx.JSON(resp); err != nil {
+			errors.Internal.Details(ctx, "unable to parse response", err.Error())
+			return
+		}
+	}
+}
+
+func Handle[Request any, Response any](handler Handler[Request, Response]) context.Handler {
+	return HandleContext(func(_ *context.Context, req Request) (Response, error) { return handler(req) })
+}
+
+```
+
+Usage Code:
+
+```go
+import (
+	"github.com/kataras/iris/v12"
+	"github.com/kataras/iris/v12/x"
+)
+
+type (
+	Req struct {
+		Email string `json:"email"`
+	}
+
+	Res struct {
+		Verified bool `json:"verified"`
+	}
+)
+
+func main() {
+	app := iris.New()
+	app.Post("/", your_package.Handle(handler))
+	app.Listen(":8080")
+}
+
+func handler(req Req) (Res, error){
+	verified := req.Email == "iris-go@outlook.com"
+	return Res{Verified: verified}, nil
+}
+```
+
+Example response:
+
+```json
+{
+    "verified": true
+}
+```
diff --git a/context/context.go b/context/context.go
index 8b726012..91120e58 100644
--- a/context/context.go
+++ b/context/context.go
@@ -3793,10 +3793,18 @@ type JSON struct {
 	ErrorHandler ErrorHandler
 }
 
-// ErrorHandler describes a context error handler. As for today this is only used
-// to globally or per-party or per-route handle JSON writes error.
-type ErrorHandler interface {
-	HandleContextError(ctx *Context, err error)
+type (
+	// ErrorHandler describes a context error handler. As for today this is only used
+	// to globally or per-party or per-route handle JSON writes error.
+	ErrorHandler interface {
+		HandleContextError(ctx *Context, err error)
+	}
+	// ErrorHandlerFunc a function shortcut for ErrorHandler interface.
+	ErrorHandlerFunc func(ctx *Context, err error)
+)
+
+func (h ErrorHandlerFunc) HandleContextError(ctx *Context, err error) {
+	h(ctx, err)
 }
 
 // IsDefault reports whether this JSON options structure holds the default values.