private Book UpdateBookCategories(Book oldBook, List <Guid> newCategoryIds, ref bool isSaved)
{
var oldBookCategories = _bookCategoryService.Where(x => x.BookId == oldBook.Id).ToList();
// create new book - category ids
var newIdsAdded = newCategoryIds.Where(id => oldBookCategories.All(bc => bc.CategoryId != id)).ToList();
if (newIdsAdded.Any())
{
_bookCategoryService.CreateMany(
newIdsAdded.Select(id => new BookCategory {
CategoryId = id, BookId = oldBook.Id
}), out isSaved
);
}
// delete old book - category ids
var oldIdsRemoved = oldBookCategories.Where(bc => !newCategoryIds.Contains(bc.CategoryId)).ToList();
if (oldIdsRemoved.Any())
{
_bookCategoryService.Delete(oldIdsRemoved, out isSaved);
}
return(oldBook);
}
