fix book-edit

[web-dave]

• import ChangeDetectorRef via DI
• Mark your Component to be checked

[web-dave]

book-edit.component.ts

import { Component, OnInit, ChangeDetectionStrategy, ChangeDetectorRef } from '@angular/core';

[web-dave]

book-edit.component.ts

constructor(
    private booksService: BooksService,
    private router: Router,
    private route: ActivatedRoute,
    private cd: ChangeDetectorRef) { }

[web-dave]

book-edit.component.ts

        this.booksService.getBook(params.isbn)
          .subscribe(b => {
            this.book = b;
            this.cd.markForCheck();
          });