/// <inheritdoc />
/// <summary>
/// Jedes Buch muss zumindest einen Autor haben.
/// Weiters darf ein Autor einem Buch nicht mehrfach zugewiesen
/// werden.
/// </summary>
/// <param name="validationContext"></param>
/// <returns></returns>
public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
{
if (BookAuthors.Count == 0)
{
yield return(new ValidationResult("Book must have at least one author"));
}
var doubleAuthorNames = BookAuthors
.GroupBy(ba => ba.Author)
.Where(baGroup => baGroup.Count() > 1)
.Select(baGroup => baGroup.Key.Name)
.ToArray()
.Join();
if (doubleAuthorNames.Length > 0)
{
yield return(new ValidationResult($"{doubleAuthorNames} are twice authors of the book"));
}
}
/// <inheritdoc />
/// <summary>
/// Jedes Buch muss zumindest einen Autor haben.
/// Weiters darf ein Autor einem Buch nicht mehrfach zugewiesen
/// werden.
/// </summary>
/// <param name="validationContext"></param>
/// <returns></returns>
public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
{
ValidationResult result = new IsbnValidation().GetValidationResult(Isbn, new ValidationContext(Isbn));
if (result != null && result != ValidationResult.Success)
{
yield return(new ValidationResult(result.ErrorMessage, new string[] { nameof(Isbn) }));
}
if (BookAuthors.Count == 0)
{
yield return(new ValidationResult("Book must have at least one author", new string[] { nameof(BookAuthors) }));
}
var duplicates = BookAuthors.GroupBy(_ => _.Author)
.Where(_ => _.Count() > 1)
.Select(_ => _.Key);
foreach (var duplicate in duplicates)
{
yield return(new ValidationResult($"{duplicate.Name} are twice authors of the book", new string[] { nameof(BookAuthors) }));
}
}
/// <inheritdoc />
/// <summary>
/// Jedes Buch muss zumindest einen Autor haben.
/// Weiters darf ein Autor einem Buch nicht mehrfach zugewiesen
/// werden.
/// </summary>
/// <param name="validationContext"></param>
/// <returns></returns>
public IEnumerable <ValidationResult> Validate(ValidationContext validationContext)
{
if (BookAuthors.Count < 1 || BookAuthors == null)
{
yield return(new ValidationResult(
"Buch muss mindestens einen Author haben",
new string[] { nameof(BookAuthors) }));
}
ValidationResult validationResult = new IsbnValidation().GetValidationResult(Isbn, new ValidationContext(Isbn));
if (validationResult != null || validationResult != ValidationResult.Success)
{
yield return(new ValidationResult(validationResult.ErrorMessage, new string[] { nameof(Isbn) }));
}
var duplicateAuthors = BookAuthors
.GroupBy(_ => _.Author)
.Where(_ => _.Count() > 1)
.Select(_ => _.Key);
foreach (var duplicateAuthor in duplicateAuthors)
{
yield return(new ValidationResult($"{duplicateAuthor.Name} are twice authors of the book", new string[] { nameof(BookAuthors) }));
}
}