From 71bd9f45002401ed29e0ba11789ac37b1c64e3c4 Mon Sep 17 00:00:00 2001
From: Manu Mtz-Almeida <manu.valladolid@gmail.com>
Date: Fri, 22 May 2015 04:43:43 +0200
Subject: [PATCH] New JSON error facilities

---
 errors.go | 35 +++++++++++++++++++++++++++++++++++
 logger.go |  5 +++--
 2 files changed, 38 insertions(+), 2 deletions(-)

diff --git a/errors.go b/errors.go
index 4aab56d2..af6b04a1 100644
--- a/errors.go
+++ b/errors.go
@@ -7,6 +7,7 @@ package gin
 import (
 	"bytes"
 	"fmt"
+	"reflect"
 )
 
 const (
@@ -36,6 +37,25 @@ func (msg *errorMsg) Meta(data interface{}) *errorMsg {
 	return msg
 }
 
+func (msg *errorMsg) JSON() interface{} {
+	json := H{}
+	if msg.Metadata != nil {
+		value := reflect.ValueOf(msg.Metadata)
+		switch value.Kind() {
+		case reflect.Struct:
+			return msg.Metadata
+		case reflect.Map:
+			for _, key := range value.MapKeys() {
+				json[key.String()] = value.MapIndex(key).Interface()
+			}
+		}
+	}
+	if _, ok := json["error"]; !ok {
+		json["error"] = msg.Error()
+	}
+	return json
+}
+
 func (msg *errorMsg) Error() string {
 	return msg.Err.Error()
 }
@@ -74,6 +94,21 @@ func (a errorMsgs) Errors() []string {
 	return errorStrings
 }
 
+func (a errorMsgs) JSON() interface{} {
+	switch len(a) {
+	case 0:
+		return nil
+	case 1:
+		return a.Last().JSON()
+	default:
+		json := make([]interface{}, len(a))
+		for i, err := range a {
+			json[i] = err.JSON()
+		}
+		return json
+	}
+}
+
 func (a errorMsgs) String() string {
 	if len(a) == 0 {
 		return ""
diff --git a/logger.go b/logger.go
index bb7b2d15..5d54606e 100644
--- a/logger.go
+++ b/logger.go
@@ -30,8 +30,9 @@ func ErrorLoggerT(typ int) HandlerFunc {
 		c.Next()
 
 		if !c.Writer.Written() {
-			if errs := c.Errors.ByType(typ); len(errs) > 0 {
-				c.JSON(-1, errs.Errors())
+			json := c.Errors.ByType(typ).JSON()
+			if json != nil {
+				c.JSON(-1, json)
 			}
 		}
 	}