对外暴露uid

 {
   "name": "yoho-js-sdk",
-  "version": "1.1.6",
+  "version": "1.1.7",
   "description": "YOHO!前端js的功能封装包，主要用于在活动页面中，对主要功能的封装。",
   "keywords": [
     "YOHO!",

@@ -25,5 +25,8 @@ export default {
     favout: user.favout,
     getMktCode: function(){
         return user.getMktCode();
-    } 
+    },
+    getUid: function(){
+        return user.uid;
+    }
 };
\ No newline at end of file

@@ -3,9 +3,31 @@
  */
 import utils from './utils';
 
+const channelMap = {
+    'baidu.com': 100000000000055,
+    'so.com': 100000000000049,
+    'sogou.com': 100000000000053,
+    'bing.com': 100000000000057,
+    'm.sm.cn': 100000000000059,
+    'google.com': 100000000000061
+};
+
+const getMktcBySeo = () => {
+    var mktc,
+        rf = document.referrer;
+
+    for (var domain in channelMap) {
+        if (rf.indexOf(domain) > -1) {
+            mktc = channelMap[domain];
+            break;
+        }
+    }
+    return mktc;
+};
+
 const getAppPath = () => {
     let qs = utils.queryString();
-    let ct = qs.mkt_code || qs.union_type;
+    let ct = qs.mkt_code || qs.union_type || getMktcBySeo() || '100000000000349';
 
     delete qs.openapp; // 防止重复打开