add flash messages

Author: efectn

ctx.go

@@ -53,6 +53,7 @@ type DefaultCtx struct {
 	viewBindMap         *dictpool.Dict       // Default view map to bind template engine
 	bind                *Bind                // Default bind reference
 	redirect            *Redirect            // Default redirect reference
+	flashMessages       string               // flash messages sent by redirection cookie
 }
 
 // Range data for c.Range
@@ -1294,3 +1295,13 @@ func (c *DefaultCtx) Bind() *Bind {
 	}
 	return c.bind
 }
+
+func (c *DefaultCtx) setFlash() {
+	c.flashMessages = c.Cookies("fiber_flash")
+
+	c.ClearCookie("fiber_flash")
+}
+
+func (c *DefaultCtx) GetFlash() error {
+	return c.SendString(c.flashMessages)
+}

ctx_interface.go

@@ -322,6 +322,10 @@ type Ctx interface {
 	// Replacement of: BodyParser, ParamsParser, GetReqHeaders, GetRespHeaders, AllParams, QueryParser, ReqHeaderParser
 	Bind() *Bind
 
+	// setFlashes is a method to get flash messages before removing them
+	setFlash()
+	GetFlash() error
+
 	// SetReq resets fields of context that is relating to request.
 	setReq(fctx *fasthttp.RequestCtx)
 
@@ -425,6 +429,7 @@ func (c *DefaultCtx) release() {
 	c.fasthttp = nil
 	c.bind = nil
 	c.redirect = nil
+	c.flashMessages = ""
 	if c.viewBindMap != nil {
 		dictpool.ReleaseDict(c.viewBindMap)
 	}

redirect.go

@@ -5,14 +5,16 @@
 package fiber
 
 import (
+	"fmt"
+
 	"github.com/valyala/bytebufferpool"
 )
 
 // Redirect is a struct to use it with Ctx.
 type Redirect struct {
-	// Embed ctx
-	c      *DefaultCtx
-	status int // Default: StatusFound
+	c        *DefaultCtx // Embed ctx
+	status   int         // Status code of redirection. Default: StatusFound
+	messages Map         // Flash messages
 }
 
 // A config to use with Redirect().Route()
@@ -26,8 +28,9 @@ type RedirectConfig struct {
 // Return default Redirect reference.
 func newRedirect(c *DefaultCtx) *Redirect {
 	return &Redirect{
-		c:      c,
-		status: StatusFound,
+		c:        c,
+		status:   StatusFound,
+		messages: make(Map, 0),
 	}
 }
 
@@ -39,6 +42,14 @@ func (r *Redirect) Status(code int) *Redirect {
 	return r
 }
 
+// You can send flash messages by using With().
+// They will be sent as a cookie.
+func (r *Redirect) With(key string, value any) *Redirect {
+	r.messages[key] = value
+
+	return r
+}
+
 // Redirect to the URL derived from the specified path, with specified status.
 func (r *Redirect) To(location string) error {
 	r.c.setCanonical(HeaderLocation, location)
@@ -62,6 +73,22 @@ func (r *Redirect) Route(name string, config ...RedirectConfig) error {
 		return err
 	}
 
+	// Flash messages
+	if len(r.messages) > 0 {
+		messageText := bytebufferpool.Get()
+		defer bytebufferpool.Put(messageText)
+
+		for k, v := range r.messages {
+			messageText.WriteString("k:" + k + ":" + fmt.Sprint(v) + ",")
+		}
+
+		r.c.Cookie(&Cookie{
+			Name:        "fiber_flash",
+			Value:       messageText.String(),
+			SessionOnly: true,
+		})
+	}
+
 	// Check queries
 	if len(cfg.Queries) > 0 {
 		queryText := bytebufferpool.Get()

router.go

@@ -160,6 +160,11 @@ func (app *App) handler(rctx *fasthttp.RequestCtx) {
 	}
 	c.Reset(rctx)
 
+	// check flash messages
+	if c.Cookies("fiber_flash") != "" {
+		c.setFlash()
+	}
+
 	// handle invalid http method directly
 	if methodInt(c.Method()) == -1 {
 		_ = c.Status(StatusBadRequest).SendString("Invalid http method")