diff options
Diffstat (limited to 'Validators')
| -rw-r--r-- | Validators/ISBNAttribute.cs | 26 |
1 files changed, 26 insertions, 0 deletions
diff --git a/Validators/ISBNAttribute.cs b/Validators/ISBNAttribute.cs new file mode 100644 index 0000000..425e9e9 --- /dev/null +++ b/Validators/ISBNAttribute.cs @@ -0,0 +1,26 @@ +using System.ComponentModel.DataAnnotations; +using LibraryAPI.Models; + +namespace LibraryAPI.Validators { + public class ISBNAttribute : ValidationAttribute { + public int ISBNlength { get; } + + public ISBNAttribute(int isbn_length) { + ISBNlength = isbn_length; + } + + public string GetErrorMessage() { + return $"ISBN strings must be {ISBNlength} characters long"; + } + + protected override ValidationResult? IsValid(object? value, ValidationContext validationContext) { + var book = (Book) validationContext.ObjectInstance; + + if(book.ISBN.Length != ISBNlength) { + return new ValidationResult(GetErrorMessage()); + } + + return ValidationResult.Success; + } + } +}
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