Attachment list for uncached attachments (#2110)

* For undownloaded attachments, set type :unknown, display them as a list in the web UI

* Fix case when attachment type is set explicitly

app/assets/javascripts/components/components/attachment_list.jsx

@@ -0,0 +1,34 @@
+import ImmutablePropTypes from 'react-immutable-proptypes';
+import PureRenderMixin from 'react-addons-pure-render-mixin';
+
+const filename = url => url.split('/').pop().split('#')[0].split('?')[0];
+
+const AttachmentList = React.createClass({
+  propTypes: {
+    media: ImmutablePropTypes.list.isRequired
+  },
+
+  mixins: [PureRenderMixin],
+
+  render () {
+    const { media } = this.props;
+
+    return (
+      <div className='attachment-list'>
+        <div className='attachment-list__icon'>
+          <i className='fa fa-link' />
+        </div>
+
+        <ul className='attachment-list__list'>
+          {media.map(attachment =>
+            <li key={attachment.get('id')}>
+              <a href={attachment.get('remote_url')} target='_blank' rel='noopener'>{filename(attachment.get('remote_url'))}</a>
+            </li>
+          )}
+        </ul>
+      </div>
+    );
+  }
+});
+
+export default AttachmentList;