[PLT-6744] Add "Only visible to you" note for ephemeral messages (#6790)

webapp/components/post_view/post_message_view/post_message_view.jsx

@@ -61,7 +61,12 @@ export default class PostMessageView extends React.PureComponent {
         /*
          * Post identifiers for selenium tests
          */
-        lastPostCount: PropTypes.number
+        lastPostCount: PropTypes.number,
+
+        /**
+         * Set to render post body compactly
+         */
+        compactDisplay: PropTypes.bool
     };
 
     static defaultProps = {
@@ -167,7 +172,13 @@ export default class PostMessageView extends React.PureComponent {
             postId = Utils.createSafeId('lastPostMessageText' + this.props.lastPostCount);
         }
 
-        const htmlFormattedText = TextFormatting.formatText(this.props.post.message, options);
+        let message = this.props.post.message;
+        const isEphemeral = Utils.isPostEphemeral(this.props.post);
+        if (this.props.compactDisplay && isEphemeral) {
+            const visibleMessage = Utils.localizeMessage('post_info.message.visible.compact', ' (Only visible to you)');
+            message = message.concat(visibleMessage);
+        }
+        const htmlFormattedText = TextFormatting.formatText(message, options);
         const postMessageComponent = this.postMessageHtmlToComponent(htmlFormattedText);
 
         return (