From b334b6a03f00305aed1a072fd3c28ec550d5cd4b Mon Sep 17 00:00:00 2001
From: smallfish <smallfish.xy@gmail.com>
Date: Tue, 5 Aug 2014 21:43:46 +0800
Subject: [PATCH] support custom struct's field tag name

---
 structure.go      | 18 ++++++++++++++++--
 structure_test.go | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 2 deletions(-)

diff --git a/structure.go b/structure.go
index 9b9a16d..563f70a 100644
--- a/structure.go
+++ b/structure.go
@@ -3,6 +3,10 @@ package structure
 
 import "reflect"
 
+var (
+	tagName = "structure" // struct's field default tag name
+)
+
 // Map converts the given s struct to a map[string]interface{}, where the keys
 // of the map are the field names and the values of the map the associated
 // values of the fields. The default key string is the struct field name but
@@ -40,7 +44,7 @@ func Map(s interface{}) map[string]interface{} {
 
 		// override if the user passed a structure tag value
 		// ignore if the user passed the "-" value
-		if tag := field.Tag.Get("structure"); tag != "" {
+		if tag := field.Tag.Get(tagName); tag != "" {
 			name = tag
 		}
 
@@ -194,6 +198,16 @@ func Has(s interface{}, fieldName string) bool {
 	return false
 }
 
+// Set struct's field tag name
+func SetTagName(n string) {
+	tagName = n
+}
+
+// Reset struct's field tag name, default: "structure"
+func ResetTagName() {
+	tagName = "structure"
+}
+
 // strctInfo returns the struct value and the exported struct fields for a
 // given s struct. This is a convenient helper method to avoid duplicate code
 // in some of the functions.
@@ -211,7 +225,7 @@ func strctInfo(s interface{}) (reflect.Value, []reflect.StructField) {
 		}
 
 		// don't check if it's omitted
-		if tag := field.Tag.Get("structure"); tag == "-" {
+		if tag := field.Tag.Get(tagName); tag == "-" {
 			continue
 		}
 
diff --git a/structure_test.go b/structure_test.go
index 94f03dc..1554723 100644
--- a/structure_test.go
+++ b/structure_test.go
@@ -89,6 +89,38 @@ func TestMap_Tag(t *testing.T) {
 
 }
 
+func TestMap_CustomTag(t *testing.T) {
+	var T = struct {
+		A string `dd:"x"`
+		B int    `dd:"y"`
+		C bool   `dd:"z"`
+	}{
+		A: "a-value",
+		B: 2,
+		C: true,
+	}
+
+	SetTagName("dd")
+	defer ResetTagName()
+	a := Map(T)
+
+	inMap := func(key interface{}) bool {
+		for k := range a {
+			if reflect.DeepEqual(k, key) {
+				return true
+			}
+		}
+		return false
+	}
+
+	for _, key := range []string{"x", "y", "z"} {
+		if !inMap(key) {
+			t.Errorf("Map should have the key %v", key)
+		}
+	}
+
+}
+
 func TestMap_Nested(t *testing.T) {
 	type A struct {
 		Name string