Improve IDE language detection logic

src/app/ide/ide.component.ts

@@ -10,6 +10,7 @@ import { DeploymentNotificationService } from '../services/deployment-notificati
 import { config } from '../config';
 import { CommandMessage } from '../message-types/command-message';
 import { LanguageMap } from './language-map';
+import { filter, first } from 'rxjs/operators';
 
 
 enum DeployButtonState {
@@ -55,11 +56,13 @@ export class IdeComponent implements OnInit {
 
   @Output() newLogs = new EventEmitter<any>();
 
-  command_handlers = {'reload':    this.reloadHandler.bind(this),
+  command_handlers = {
+    'reload':    this.reloadHandler.bind(this),
     'read':      this.readHandler.bind(this),
     'select':    this.selectHandler.bind(this),
     'write':     this.writeHandler.bind(this),
-                      'selectdir': this.selectdirHandler.bind(this)};
+    'selectdir': this.selectdirHandler.bind(this)
+  };
 
   constructor(private webSocketService: WebSocketService,
               private changeDetectorRef: ChangeDetectorRef,
@@ -69,6 +72,7 @@ export class IdeComponent implements OnInit {
   ngOnInit() {
     this.webSocketService.connect();
     this.subscribeWS();
+    this.subscribeFirstLanguageDetection();
     this.requestCode();
     this.initProcessManagerService();
     this.resetAutoSaveCountdown();
@@ -81,6 +85,15 @@ export class IdeComponent implements OnInit {
     });
   }
 
+  subscribeFirstLanguageDetection() {
+    this.webSocketService.observeKey<CommandMessage>(this.key_id).pipe(
+      filter(message =>  message.data.command === 'read'),
+      first()
+    ).subscribe(
+      () => this.autoDetectEditorLanguageIfEnabled(this.filename)
+    );
+  }
+
   initProcessManagerService() {
     this.processManagerService.init();
     this.processManagerService.subscribeCallback(
@@ -101,7 +114,7 @@ export class IdeComponent implements OnInit {
 
     this.processManagerService.subscribeErrorCallback(
       config.ide.deployProcessName,
-      (event) => this.setDeployButtonState(DeployButtonState.FAILED)
+      () => this.setDeployButtonState(DeployButtonState.FAILED)
     );
   }
 
@@ -114,6 +127,7 @@ export class IdeComponent implements OnInit {
 
   selectHandler(data: IDECommand) {
     this.updateFileData(data);
+    this.autoDetectEditorLanguageIfEnabled(this.filename);
   }
 
   reloadHandler(data: CommandMessage) {
@@ -124,9 +138,6 @@ export class IdeComponent implements OnInit {
     if (this.codeState === CodeState.SAVED) {
       this.updateFileData(data);
     }
-    if (config.ide.autoDetectFileLanguage) {
-      this.autoDetectEditorLanguage(data.filename);
-    }
   }
 
   writeHandler(data: CommandMessage) {
@@ -137,7 +148,10 @@ export class IdeComponent implements OnInit {
     this.updateFileData(data);
   }
 
-  autoDetectEditorLanguage(filename: string) {
+  autoDetectEditorLanguageIfEnabled(filename: string) {
+    if (!config.ide.autoDetectFileLanguage) {
+      return;
+    }
     const extension = filename.substr(filename.lastIndexOf('.') + 1);
     let language = LanguageMap[extension];
     language = (language === undefined) ? 'text' : language;