Exclude echarts from server-side rendering

frontend/src/app/shared/directives/browser-only.directive.ts

@@ -0,0 +1,19 @@
+import { Directive, TemplateRef, ViewContainerRef, Inject, PLATFORM_ID } from '@angular/core';
+import { isPlatformBrowser } from '@angular/common';
+
+@Directive({
+  selector: '[browserOnly]'
+})
+export class BrowserOnlyDirective {
+  constructor(
+    private templateRef: TemplateRef<any>,
+    private viewContainer: ViewContainerRef,
+    @Inject(PLATFORM_ID) private platformId: Object
+  ) {
+    if (isPlatformBrowser(this.platformId)) {
+      this.viewContainer.createEmbeddedView(this.templateRef);
+    } else {
+      this.viewContainer.clear();
+    }
+  }
+}