Defining the view interface

Add the following interface to mediaman.ts:

interface MediaManView { 
    getNewBookCollectionName(): string; 
    renderBookCollection(bookCollection: 
    Readonly<MediaCollection<Book>>): void; 
    displayErrorMessage(message: string): void; 
    clearBookCollections(): void; 
    removeBookCollection(identifier: string): void; 
    getNewBookDetails(collectionIdentifier: string): { error?: string, 
    book?: Readonly<Book> }; 
    renderBook(collectionIdentifier: string, book: Readonly<Book>): 
    void; 
    removeBook(collectionIdentifier: string, bookIdentifier: string): 
    void; 
    clearNewBookCollectionForm(collectionIdentifier: string): void; 
} 

As in the previous chapter, the different view methods will hide internal details for the controller, which will simply use the view implementation as a black box. Again...