Implement webide file changing with poc text input

src/app/webide/webide.component.html

@@ -1,3 +1,6 @@
+<input [(ngModel)]="filename">
+<button (click)="selectCode(); requestCode()" type="submit" class="btn btn-primary">Select file</button>
+
 <div
   ace-editor
   [(text)]="code"

src/app/webide/webide.component.ts

@@ -44,4 +44,10 @@ export class WebideComponent implements OnInit {
     });
   }
 
+  selectCode() {
+    this.webSocketService.send(this.anchor_id, {
+      'command': 'select',
+      'filename': this.filename
+    });
+  }
 }