Learn TypeScript 3 by Building Web Applications

Implementing the removeBook method

The last method that we need to implement is removeBook. Here, we'll simply retrieve the DOM node corresponding to the book (that is, the table row) and remove it:

removeBook(collectionIdentifier: string, bookIdentifier: string) { 
    if (!collectionIdentifier) { 
        throw new Error("The collection identifier must be provided!"); 
    } 
 
    if (!bookIdentifier) { 
        throw new Error("The book identifier must be provided!"); 
    } 
 
    const bookElement = document.getElementById    (`book-${collectionIdentifier}-${bookIdentifier}`)     as HTMLInputElement; 
    if (!bookElement) { 
        throw new Error("The element corresponding to the book to         remove could not be found! Did the template change?"); 
    } 
 
    bookElement.remove(); 
} 

Voilà! Our view is now fully ...