building all type of outgoing msg template (not tested)

outMsg.go

 
 import (
 	"crypto/sha1"
+	"errors"
 	"fmt"
+	"log"
 	"math/rand"
 	"sort"
 	"strings"
 	"time"
 )
 
+//Article is one item in News Message
+// one such message can contains upto 10 Articles
+type Article struct {
+	title, description, picURL, url string
+}
+
 //BuildTextMsg Given a text message send it to wechat client
-func BuildTextMsg(txt string, ToUserName string) (string, error) {
+func BuildTextMsg(txt string, ToUserName string) (xml string, err error) {
+	if txt == "" || ToUserName == "" {
+		err = errors.New("Empty text body or Empty destination")
+		xml = ""
+		return
+	}
 
-	template := `<xml>
- <ToUserName><![CDATA[%s]]></ToUserName>
- <FromUserName><![CDATA[%s]]></FromUserName>
- <CreateTime>%d</CreateTime>
- <MsgType><![CDATA[text]]></MsgType>
- <Content><![CDATA[%s]]></Content>
- </xml>`
-	msg := fmt.Sprintf(template, ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), txt)
+	msg := fmt.Sprintf(txtMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), txt)
 	e := Encode(msg)
-	str, _, _, _ := signMsg(e)
-	return str, nil
+	xml, _, _, _ = signMsg(e)
+	return
 }
 
 func signMsg(content string) (xml string, timestamp int32, nonce int32, signature string) {
 	signature = fmt.Sprintf("%x", h.Sum(nil))
 	return
 }
+
+func buildTxtMsg(ToUserName, content string) (msg string) {
+	msg = fmt.Sprintf(txtMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), content)
+	return
+}
+func txtMsgTemplate() string {
+	return `<xml>
+ <ToUserName><![CDATA[%s]]></ToUserName>
+ <FromUserName><![CDATA[%s]]></FromUserName>
+ <CreateTime>%d</CreateTime>
+ <MsgType><![CDATA[text]]></MsgType>
+ <Content><![CDATA[%s]]></Content>
+ </xml>`
+}
+
+func buildPicMsg(ToUserName, mediaID string) (msg string) {
+	msg = fmt.Sprintf(picMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), mediaID)
+	return
+}
+func picMsgTemplate() string {
+	return `<xml>
+<ToUserName><![CDATA[%s]]></ToUserName>
+<FromUserName><![CDATA[%s]]></FromUserName>
+<CreateTime>%d</CreateTime>
+<MsgType><![CDATA[image]]></MsgType>
+<Image>
+<MediaId><![CDATA[%s]]></MediaId>
+</Image>
+</xml>`
+}
+
+func buildVoiceMsg(ToUserName, mediaID string) (msg string) {
+	msg = fmt.Sprintf(voiceMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), mediaID)
+	return
+}
+func voiceMsgTemplate() string {
+	return `<xml>
+<ToUserName><![CDATA[%s]]></ToUserName>
+<FromUserName><![CDATA[%s]]></FromUserName>
+<CreateTime>%d</CreateTime>
+<MsgType><![CDATA[voice]]></MsgType>
+<Voice>
+<MediaId><![CDATA[%s]]></MediaId>
+</Voice>
+</xml>`
+}
+
+func buildVideoMsg(ToUserName, mediaID, title, description string) (msg string) {
+	msg = fmt.Sprintf(videoMsgTemplate(), ToUserName, APIConfig.PublicAccountID, int32(time.Now().Unix()), mediaID, title, description)
+	return
+}
+func videoMsgTemplate() string {
+	return `<xml>
+<ToUserName><![CDATA[%s]]></ToUserName>
+<FromUserName><![CDATA[%s]]></FromUserName>
+<CreateTime>%d</CreateTime>
+<MsgType><![CDATA[video]]></MsgType>
+<Video>
+<MediaId><![CDATA[%s]]></MediaId>
+<Title><![CDATA[%s]]></Title>
+<Description><![CDATA[%s]]></Description>
+</Video> 
+</xml>`
+}
+
+func bulidMusicMsg(ToUserName, mediaID, title, description, url, hqURL string) (msg string) {
+	msg = fmt.Sprintf(musicMsgTemplate(),
+		ToUserName,
+		APIConfig.PublicAccountID,
+		int32(time.Now().Unix()),
+		title,
+		description,
+		url,
+		hqURL,
+		mediaID)
+	return
+}
+func musicMsgTemplate() string {
+	return `<xml>
+<ToUserName><![CDATA[toUser]]></ToUserName>
+<FromUserName><![CDATA[fromUser]]></FromUserName>
+<CreateTime>12345678</CreateTime>
+<MsgType><![CDATA[music]]></MsgType>
+<Music>
+<Title><![CDATA[TITLE]]></Title>
+<Description><![CDATA[DESCRIPTION]]></Description>
+<MusicUrl><![CDATA[MUSIC_Url]]></MusicUrl>
+<HQMusicUrl><![CDATA[HQ_MUSIC_Url]]></HQMusicUrl>
+<ThumbMediaId><![CDATA[media_id]]></ThumbMediaId>
+</Music>
+</xml>`
+}
+
+func buildNewsMsg(ToUserName, title, description string, articles []Article) (msg string) {
+	count := len(articles)
+	if count <= 0 {
+		log.Fatal("using empty article to build NewsMsg")
+		msg = ""
+		return
+	}
+
+	items := []string{}
+	for _, a := range articles {
+		s := buildArticleItem(a)
+		items = append(items, s)
+	}
+	strItems := strings.Join(items, "")
+
+	msg = fmt.Sprintf(newsMsgTemplate(),
+		ToUserName,
+		APIConfig.PublicAccountID,
+		int32(time.Now().Unix()),
+		count,
+		strItems)
+	return
+}
+
+func buildArticleItem(item Article) (article string) {
+	template := `<item>
+<Title><![CDATA[%s]]></Title> 
+<Description><![CDATA[%s]]></Description>
+<PicUrl><![CDATA[%s]]></PicUrl>
+<Url><![CDATA[%s]]></Url>
+</item>
+`
+	article = fmt.Sprintf(template,
+		item.title, item.description, item.picURL, item.url)
+	return article
+}
+
+func newsMsgTemplate() string {
+	return `<xml>
+<ToUserName><![CDATA[%s]]></ToUserName>
+<FromUserName><![CDATA[%s]]></FromUserName>
+<CreateTime>%d</CreateTime>
+<MsgType><![CDATA[news]]></MsgType>
+<ArticleCount>%d</ArticleCount>
+<Articles>
+%s
+</Articles>
+</xml>`
+}