Merge pull request imroc#50 from kazekim/master

use HeaderFromStruct function to create header from struct to make we work easier

README.md

@@ -105,6 +105,25 @@ header.Set("Accept", "application/json")
 req.Get("https://www.baidu.com", header)
 ```
 
+#### Set Header From Struct
+Use `HeaderFromStruct` func to parse your struct
+``` go
+type HeaderStruct struct {
+		UserAgent string `json:"User-Agent"`
+		Authorization string `json:"Authorization"`
+	}
+
+	h := HeaderStruct{
+		"V1.0.0",
+		"roc",
+	}
+
+	authHeader := req.HeaderFromStruct(h) 
+	req.Get("https://www.baidu.com", authHeader, req.Header{"User-Agent": "V1.1"})
+```
+
+Note: Please add tag 'json' to your argument in struct to let you customize the key name of your header
+
 ## <a name="Set-Param">Set Param</a>
 Use `req.Param` (it is actually a `map[string]interface{}`)
 ``` go

header.go

@@ -0,0 +1,41 @@
+/*
+  GoLang code created by Jirawat Harnsiriwatanakit https://github.com/kazekim
+*/
+
+package req
+
+import "encoding/json"
+
+// Header represents http request header
+type Header map[string]string
+
+func (h Header) Clone() Header {
+	if h == nil {
+		return nil
+	}
+	hh := Header{}
+	for k, v := range h {
+		hh[k] = v
+	}
+	return hh
+}
+
+// ParseStruct parse struct into header
+func ParseStruct(h Header, v interface{}) Header {
+	data, err := json.Marshal(v)
+	if err != nil {
+		return h
+	}
+
+	err = json.Unmarshal(data, &h)
+	return h
+}
+
+// HeaderFromStruct init header from struct
+func HeaderFromStruct(v interface{}) Header {
+
+	var header Header
+	header = ParseStruct(header, v)
+	return header
+}
+

header_test.go

@@ -0,0 +1,47 @@
+/*
+  GoLang code created by Jirawat Harnsiriwatanakit https://github.com/kazekim
+*/
+
+package req
+
+import "testing"
+
+func TestParseStruct(t *testing.T) {
+
+	type HeaderStruct struct {
+		UserAgent     string `json:"User-Agent"`
+		Authorization string `json:"Authorization"`
+	}
+
+	h := HeaderStruct{
+		"V1.0.0",
+		"roc",
+	}
+
+	var header Header
+	header = ParseStruct(header, h)
+
+	if header["User-Agent"] != h.UserAgent && header["Authorization"] != h.Authorization {
+		t.Fatal("struct parser for header is not working")
+	}
+
+}
+
+func TestHeaderFromStruct(t *testing.T) {
+
+	type HeaderStruct struct {
+		UserAgent string `json:"User-Agent"`
+		Authorization string `json:"Authorization"`
+	}
+
+	h := HeaderStruct{
+		"V1.0.0",
+		"roc",
+	}
+
+	header := HeaderFromStruct(h)
+
+	if header["User-Agent"] != h.UserAgent && header["Authorization"] != h.Authorization {
+		t.Fatal("struct parser for header is not working")
+	}
+}

req.go

@@ -34,20 +34,6 @@ const (
 	LstdFlags = LreqHead | LreqBody | LrespHead | LrespBody
 )
 
-// Header represents http request header
-type Header map[string]string
-
-func (h Header) Clone() Header {
-	if h == nil {
-		return nil
-	}
-	hh := Header{}
-	for k, v := range h {
-		hh[k] = v
-	}
-	return hh
-}
-
 // Param represents  http request param
 type Param map[string]interface{}