password strength checks during registration

src/app/components/password-strength.component.ts

@@ -0,0 +1,44 @@
+import {
+    Component,
+    Input,
+    OnChanges,
+} from '@angular/core';
+
+import { I18nService } from 'jslib/abstractions/i18n.service';
+
+@Component({
+    selector: 'app-password-strength',
+    templateUrl: 'password-strength.component.html',
+})
+export class PasswordStrengthComponent implements OnChanges {
+    @Input() score?: number;
+    @Input() showText = false;
+
+    scoreWidth = 0;
+    color = 'bg-danger';
+    text: string;
+
+    constructor(private i18nService: I18nService) { }
+
+    ngOnChanges(): void {
+        this.scoreWidth = this.score == null ? 0 : (this.score + 1) * 20;
+        switch (this.score) {
+            case 4:
+                this.color = 'bg-success';
+                this.text = this.i18nService.t('strong');
+                break;
+            case 3:
+                this.color = 'bg-warning';
+                this.text = this.i18nService.t('ok');
+                break;
+            case 2:
+                this.color = 'bg-warning';
+                this.text = this.i18nService.t('weak');
+                break;
+            default:
+                this.color = 'bg-danger';
+                this.text = this.score != null ? this.i18nService.t('weak') : null;
+                break;
+        }
+    }
+}