WIP: Implement frontend

frontend/src/app/components/error-dialog/error-dialog.component.ts

@@ -0,0 +1,32 @@
+import {Component, Inject, OnInit} from '@angular/core';
+import {MAT_DIALOG_DATA, MatDialogRef} from '@angular/material/dialog';
+
+@Component({
+  selector: 'app-error-dialog',
+  template: `
+    <h1 mat-dialog-title>Error</h1>
+    <mat-dialog-content>
+      {{message}}
+    </mat-dialog-content>
+    <mat-dialog-actions style="justify-content: end">
+      <button mat-raised-button color="primary" (click)="onClick()">OK</button>
+    </mat-dialog-actions>
+  `
+})
+export class ErrorDialogComponent implements OnInit {
+
+  message: string;
+
+  constructor(public dialogRef: MatDialogRef<ErrorDialogComponent>,
+              @Inject(MAT_DIALOG_DATA) data: any) {
+    this.message = data.message;
+  }
+
+  ngOnInit() {
+  }
+
+  onClick(): void {
+    this.dialogRef.close();
+  }
+
+}