public async Task <ActionResult <BookDto> > CreateBookForAuthorAsync(Guid authorId, [FromBody] BookForCreationDto book)
{
if (book == null)
{
return(BadRequest());
}
// As the [ApiController] attribute, the common validation is handled by it, such as model binding.
// So only custom validation is handled by this code
if (book.Description == book.Title)
{
ModelState.AddModelError(nameof(BookForCreationDto),
"The provided description should be different from the title.");
}
if (!ModelState.IsValid)
{
// return 422
return(new UnprocessableEntityObjectResult(ModelState));
}
if (!await _libraryRepository.AuthorExistsAsync(authorId))
{
return(NotFound());
}
var bookEntity = _mapper.Map <Book>(book);
await _libraryRepository.AddBookForAuthorAsync(authorId, bookEntity);
if (!await _libraryRepository.SaveChangesAsync())
{
throw new Exception($"Creating a book for author {authorId} failed on save.");
}
var bookToReturn = _mapper.Map <BookDto>(bookEntity);
return(CreatedAtRoute(
"GetBookForAuthor",
new { authorId = authorId, bookId = bookToReturn.Id },
CreateLinksForBook(bookToReturn)));
}