From bcdc8cecd769a495bca516a0194e847e11a013eb Mon Sep 17 00:00:00 2001
From: Andy Pan <panjf2000@gmail.com>
Date: Fri, 18 Nov 2022 20:51:05 +0800
Subject: [PATCH] :memo: Update middleware/logger docs

Update #2219
---
 middleware/logger/README.md | 96 +++++++++++++++++++++----------------
 1 file changed, 56 insertions(+), 40 deletions(-)

diff --git a/middleware/logger/README.md b/middleware/logger/README.md
index f6a70117110..814bc49b673 100644
--- a/middleware/logger/README.md
+++ b/middleware/logger/README.md
@@ -87,56 +87,72 @@ app.Use(logger.New(logger.Config{
 }))
 ```
 
+### Callback after log is written
+
+```go
+app.Use(logger.New(logger.Config{
+	TimeFormat: time.RFC3339Nano,
+	TimeZone:   "Asia/Shanghai",
+	Done: func(c *fiber.Ctx, logString []byte) {
+		if c.Response().StatusCode() != fiber.StatusOK {
+			reporter.SendToSlack(logString) 
+		}
+	},
+}))
+```
+
 ## Config
 ```go
 // Config defines the config for middleware.
 type Config struct {
-	// Next defines a function to skip this middleware when returned true.
-	//
-	// Optional. Default: nil
-	Next func(c *fiber.Ctx) bool
-
-	// CustomTags defines the custom tag action
-	//
-	// Optional. Default: map[string]LogFunc{}
-	CustomTags map[string]LogFunc
-	
-	// Format defines the logging tags
-	//
-	// Optional. Default: [${time}] ${status} - ${latency} ${method} ${path}\n
-	Format string
-	
-	// TimeFormat https://programming.guide/go/format-parse-string-time-date-example.html
-	//
-	// Optional. Default: 15:04:05
-	TimeFormat string
-
-	// TimeZone can be specified, such as "UTC" and "America/New_York" and "Asia/Chongqing", etc
-	//
-	// Optional. Default: "Local"
-	TimeZone string
-
-	// TimeInterval is the delay before the timestamp is updated
-	//
-	// Optional. Default: 500 * time.Millisecond
-	TimeInterval time.Duration
-
-	// Output is a writer where logs are written
-	//
-	// Default: os.Stderr
-	Output io.Writer
+    // Next defines a function to skip this middleware when returned true.
+    //
+    // Optional. Default: nil
+    Next func(c *fiber.Ctx) bool
+    
+    // Done is a function that is called after the log string for a request is written to Output,
+    // and pass the log string as parameter.
+    //
+    // Optional. Default: nil
+    Done func(c *fiber.Ctx, logString []byte)
+
+    // Format defines the logging tags
+    //
+    // Optional. Default: [${time}] ${status} - ${latency} ${method} ${path}\n
+    Format string
+
+    // TimeFormat https://programming.guide/go/format-parse-string-time-date-example.html
+    //
+    // Optional. Default: 15:04:05
+    TimeFormat string
+
+    // TimeZone can be specified, such as "UTC" and "America/New_York" and "Asia/Chongqing", etc
+    //
+    // Optional. Default: "Local"
+    TimeZone string
+
+    // TimeInterval is the delay before the timestamp is updated
+    //
+    // Optional. Default: 500 * time.Millisecond
+    TimeInterval time.Duration
+
+    // Output is a writter where logs are written
+    //
+    // Default: os.Stderr
+    Output io.Writer
 }
 ```
 
 ## Default Config
 ```go
 var ConfigDefault = Config{
-	Next:         nil,
-	Format:       "[${time}] ${status} - ${latency} ${method} ${path}\n",
-	TimeFormat:   "15:04:05",
-	TimeZone:     "Local",
-	TimeInterval: 500 * time.Millisecond,
-	Output:       os.Stderr,
+    Next:         nil,
+    Done:         nil,
+    Format:       "[${time}] ${status} - ${latency} ${method} ${path}\n",
+    TimeFormat:   "15:04:05",
+    TimeZone:     "Local",
+    TimeInterval: 500 * time.Millisecond,
+    Output:       os.Stderr,
 }
 ```