Add header to trends section and change refresh rate to 15 minutes (mastodon#11641)

Author: Gargron

app/javascript/mastodon/features/getting_started/components/trends.js

@@ -3,6 +3,7 @@ import ImmutablePureComponent from 'react-immutable-pure-component';
 import PropTypes from 'prop-types';
 import ImmutablePropTypes from 'react-immutable-proptypes';
 import Hashtag from 'mastodon/components/hashtag';
+import { FormattedMessage } from 'react-intl';
 
 export default class Trends extends ImmutablePureComponent {
 
@@ -17,7 +18,7 @@ export default class Trends extends ImmutablePureComponent {
 
   componentDidMount () {
     this.props.fetchTrends();
-    this.refreshInterval = setInterval(() => this.props.fetchTrends(), 3600000);
+    this.refreshInterval = setInterval(() => this.props.fetchTrends(), 900 * 1000);
   }
 
   componentWillUnmount () {
@@ -35,6 +36,8 @@ export default class Trends extends ImmutablePureComponent {
 
     return (
       <div className='getting-started__trends'>
+        <h4><FormattedMessage id='trends.trending_now' defaultMessage='Trending now' /></h4>
+
         {trends.take(3).map(hashtag => <Hashtag key={hashtag.get('name')} hashtag={hashtag} />)}
       </div>
     );

app/javascript/styles/mastodon/components.scss

@@ -2765,6 +2765,15 @@ a.account__display-name {
     animation: fade 150ms linear;
     margin-top: 10px;
 
+    h4 {
+      font-size: 12px;
+      text-transform: uppercase;
+      color: $darker-text-color;
+      padding: 10px;
+      font-weight: 500;
+      border-bottom: 1px solid lighten($ui-base-color, 8%);
+    }
+
     @media screen and (max-height: 810px) {
       .trends__item:nth-child(3) {
         display: none;