Refactor NPS poll component to separate poll and wrapper components

[MAILPOET-1815]

assets/js/src/nps_poll.jsx

@@ -4,8 +4,7 @@ import ReactDOMServer from 'react-dom/server';
 import ReviewRequest from 'review_request.jsx';
 import getTrackingData from 'analytics.js';
 
-const withNpsPoll = function withNpsPoll(Component) {
+class NpsPoll extends React.Component {
-  return class extends React.Component {
   constructor(props) {
     super(props);
     this.state = {
@@ -80,10 +79,10 @@ const withNpsPoll = function withNpsPoll(Component) {
 
   render() {
     if (!window.mailpoet_display_nps_poll) {
-        return (<Component {...this.props} />);
+      return null;
     }
     if (window.satismeter) {
-        this.displayPoll();
+      setImmediate(this.displayPoll);
     } else {
       const s = document.createElement('script');
       s.type = 'text/javascript';
@@ -91,9 +90,17 @@ const withNpsPoll = function withNpsPoll(Component) {
       s.onload = () => this.displayPoll();
       document.getElementsByTagName('body')[0].appendChild(s);
     }
-      return (<Component {...this.props} />);
+    return null;
   }
-  };
+}
+
+const withNpsPoll = function withNpsPoll(Component) {
+  return props => (
+    <>
+      <NpsPoll />
+      <Component {...props} />
+    </>
+  );
 };
 
 export default withNpsPoll;