Add ga event analytic code

package.json

@@ -98,6 +98,7 @@
     "cross-env": "^4.0.0",
     "css-split-webpack-plugin": "^0.2.3",
     "dekko": "^0.2.0",
+    "delegate": "^3.1.2",
     "dora-plugin-upload": "^0.3.1",
     "enquire.js": "^2.1.1",
     "enzyme": "^2.6.0",
@@ -214,7 +215,9 @@
       "/node_modules/",
       "/dist/antd.js"
     ],
-    "snapshotSerializers": ["enzyme-to-json/serializer"]
+    "snapshotSerializers": [
+      "enzyme-to-json/serializer"
+    ]
   },
   "pre-commit": [
     "lint-staged"

site/theme/template/Content/Article.jsx

@@ -3,6 +3,7 @@ import { FormattedMessage } from 'react-intl';
 import DocumentTitle from 'react-document-title';
 import { getChildren } from 'jsonml.js/lib/utils';
 import { Timeline } from 'antd';
+import delegate from 'delegate';
 import EditButton from './EditButton';
 import * as utils from '../utils';
 
@@ -11,6 +12,12 @@ export default class Article extends React.Component {
     intl: PropTypes.object.isRequired,
   }
   componentDidMount() {
+    // Add ga event click
+    this.delegation = delegate(this.node, '.resource-card', 'click', (e) => {
+      if (window.ga) {
+        window.ga('send', 'event', 'Download', 'resource', e.delegateTarget.href);
+      }
+    }, false);
     this.componentDidUpdate();
   }
   componentDidUpdate() {
@@ -30,6 +37,9 @@ export default class Article extends React.Component {
   }
   componentWillUnmount() {
     clearTimeout(this.pingTimer);
+    if (this.delegation) {
+      this.delegation.destroy();
+    }
   }
   getArticle(article) {
     const { content } = this.props;
@@ -64,7 +74,7 @@ export default class Article extends React.Component {
     const locale = this.context.intl.locale;
     return (
       <DocumentTitle title={`${title[locale] || title} - Ant Design`}>
-        <article className="markdown">
+        <article className="markdown" ref={(node) => { this.node = node; }}>
           <h1>
             {title[locale] || title}
             {