Lobby required displayname (#1231)

* ref: Fix imports order.

* feat: Adds display name required connection event.

JitsiConnectionEvents.js

  * connection is not in the correct state(connected, disconnected, etc.)
  */
 export const WRONG_STATE = 'connection.wrongState';
+
+/**
+ * Indicates that the display name is required over this connection and need to be supplied when
+ * joining the room.
+ * There are cases like lobby room where display name is required.
+ */
+export const DISPLAY_NAME_REQUIRED = 'connection.display_name_required';

modules/xmpp/Caps.js

      * @param {int} timeout the timeout in ms for reply from the host.
      * @returns {Promise<Set<String>, Error>}
      */
-    getFeaturesAndIdentities(jid, timeout = 5000) {
-        return this._getDiscoInfo(jid, null, timeout);
+    getFeaturesAndIdentities(jid, node, timeout = 5000) {
+        return this._getDiscoInfo(jid, node, timeout);
     }
 
     /**

modules/xmpp/xmpp.js

 import { $msg, Strophe } from 'strophe.js';
 import 'strophejs-plugin-disco';
 
-import RandomUtil from '../util/RandomUtil';
 import * as JitsiConnectionErrors from '../../JitsiConnectionErrors';
 import * as JitsiConnectionEvents from '../../JitsiConnectionEvents';
+import XMPPEvents from '../../service/xmpp/XMPPEvents';
 import browser from '../browser';
+import GlobalOnErrorHandler from '../util/GlobalOnErrorHandler';
+import Listenable from '../util/Listenable';
+import RandomUtil from '../util/RandomUtil';
+
+import Caps from './Caps';
+import XmppConnection from './XmppConnection';
 import MucConnectionPlugin from './strophe.emuc';
 import JingleConnectionPlugin from './strophe.jingle';
-import initStropheUtil from './strophe.util';
+import initStropheLogger from './strophe.logger';
 import PingConnectionPlugin from './strophe.ping';
 import RayoConnectionPlugin from './strophe.rayo';
-import initStropheLogger from './strophe.logger';
-import Listenable from '../util/Listenable';
-import Caps from './Caps';
-import GlobalOnErrorHandler from '../util/GlobalOnErrorHandler';
-import XMPPEvents from '../../service/xmpp/XMPPEvents';
-import XmppConnection from './XmppConnection';
+import initStropheUtil from './strophe.util';
 
 const logger = getLogger(__filename);
 
 
                         if (identity.type === 'lobbyrooms') {
                             this.lobbySupported = true;
+                            identity.name && this.caps.getFeaturesAndIdentities(identity.name, identity.type)
+                                .then(({ features: f }) => {
+                                    f.forEach(fr => {
+                                        if (fr.endsWith('#displayname_required')) {
+                                            this.eventEmitter.emit(
+                                                JitsiConnectionEvents.DISPLAY_NAME_REQUIRED);
+                                        }
+                                    });
+                                })
+                                .catch(logger.warn('Error getting features from lobby.'));
                         }
                     });