Merge pull request #1626 from mattermost/PLT-1355

PLT-1355 Move link preview into pre-release feature

web/react/components/post_body.jsx

@@ -6,6 +6,7 @@ import UserStore from '../stores/user_store.jsx';
 import * as Utils from '../utils/utils.jsx';
 import * as Emoji from '../utils/emoticons.jsx';
 import Constants from '../utils/constants.jsx';
+const PreReleaseFeatures = Constants.PRE_RELEASE_FEATURES;
 import * as TextFormatting from '../utils/text_formatting.jsx';
 import twemoji from 'twemoji';
 import PostBodyAdditionalContent from './post_body_additional_content.jsx';
@@ -109,12 +110,14 @@ export default class PostBody extends React.Component {
 
         const trimmedLink = link.trim();
 
-        const provider = this.getOembedProvider(trimmedLink);
-        if (provider != null) {
-            post.props.oEmbedLink = trimmedLink;
-            post.type = 'oEmbed';
-            this.setState({post, provider});
-            return '';
+        if (Utils.isFeatureEnabled(PreReleaseFeatures.EMBED_PREVIEW)) {
+            const provider = this.getOembedProvider(trimmedLink);
+            if (provider != null) {
+                post.props.oEmbedLink = trimmedLink;
+                post.type = 'oEmbed';
+                this.setState({post, provider});
+                return '';
+            }
         }
 
         const embed = this.createYoutubeEmbed(link);

web/react/components/user_settings/user_settings_advanced.jsx

@@ -195,7 +195,7 @@ export default class AdvancedSettingsDisplay extends React.Component {
                 inputs.push(
                     <div key='advancedPreviewFeatures_helptext'>
                         <br/>
-                        {'Check any pre-released features you\'d like to preview.'}
+                        {'Check any pre-released features you\'d like to preview.  You may also need to refresh the page before the setting will take effect.'}
                     </div>
                 );
 

web/react/utils/constants.jsx

@@ -432,6 +432,10 @@ export default {
         MARKDOWN_PREVIEW: {
             label: 'markdown_preview', // github issue: https://github.com/mattermost/platform/pull/1389
             description: 'Show markdown preview option in message input box'
+        },
+        EMBED_PREVIEW: {
+            label: 'embed_preview',
+            description: 'Show preview snippet of links below message'
         }
     }
 };