/// <summary>
/// Determines whether a string contains only printable characters.
/// </summary>
/// <param name="stringToCheck">The string to check.</param>
/// <returns>
/// <c>true</c> if the string contains only printable characters; otherwise, <c>false</c>.
/// </returns>
public static bool IsPrintableCharacter(this string stringToCheck)
{
if (string.IsNullOrEmpty(stringToCheck))
{
return(false);
}
// get the alphabet provider
IAlphabetProvider provider = new EnglishAlphabetProvider();
// get the printable character set
var result = provider.GetPrintableCharacters().ToArray();
// return false if the character in the string is not found in printable character set
return(stringToCheck.All(result.Contains));
}
/// <summary>
/// Validates the specified value with respect to the current validation attribute.
/// </summary>
/// <param name="value">
/// The value to validate.
/// </param>
/// <param name="validationContext">
/// The context information about the validation operation.
/// </param>
/// <returns>
/// An instance of the <see cref="T:System.ComponentModel.DataAnnotations.ValidationResult"/> class.
/// </returns>
protected override ValidationResult PerformCustomValidation(object value, ValidationContext validationContext)
{
if (value.IsNull())
{
return(ValidationResult.Success);
}
string convertedValue;
if (validationContext.IsNull())
{
validationContext = new ValidationContext(value, null, null)
{
DisplayName = "The value"
};
}
var memberNames = new[] { validationContext.MemberName };
try
{
convertedValue = Convert.ToString(value);
}
catch (FormatException)
{
this.ErrorMessage = validationContext.DisplayName.FormattedWith(ValidationMessages.ValueMustBeString);
return(new ValidationResult(this.ErrorMessage));
}
if (!convertedValue.IsPrintableCharacter())
{
var englishAlphabetProvider = new EnglishAlphabetProvider();
string extendedCharacters = string.Join(string.Empty, englishAlphabetProvider.GetPrintableCharacters());
this.ErrorMessage = string.Format(ValidationMessages.CanOnlyContainPrintableCharacters, validationContext.DisplayName, extendedCharacters);
return(new ValidationResult(this.ErrorMessage, memberNames));
}
return(ValidationResult.Success);
}
/// <summary>
/// Validates the specified value with respect to the current validation attribute.
/// </summary>
/// <param name="value">
/// The value to validate.
/// </param>
/// <param name="validationContext">
/// The context information about the validation operation.
/// </param>
/// <returns>
/// An instance of the <see cref="T:System.ComponentModel.DataAnnotations.ValidationResult"/> class.
/// </returns>
protected override ValidationResult PerformCustomValidation(object value, ValidationContext validationContext)
{
if (value.IsNull())
{
return ValidationResult.Success;
}
string convertedValue;
if (validationContext.IsNull())
{
validationContext = new ValidationContext(value, null, null) { DisplayName = "The value" };
}
var memberNames = new[] { validationContext.MemberName };
try
{
convertedValue = Convert.ToString(value);
}
catch (FormatException)
{
this.ErrorMessage = validationContext.DisplayName.FormattedWith(ValidationMessages.ValueMustBeString);
return new ValidationResult(this.ErrorMessage);
}
if (!convertedValue.IsPrintableCharacter())
{
var englishAlphabetProvider = new EnglishAlphabetProvider();
string extendedCharacters = string.Join(string.Empty, englishAlphabetProvider.GetPrintableCharacters());
this.ErrorMessage = string.Format(ValidationMessages.CanOnlyContainPrintableCharacters, validationContext.DisplayName, extendedCharacters);
return new ValidationResult(this.ErrorMessage, memberNames);
}
return ValidationResult.Success;
}
public void ReturnPrintableCharacters()
{
// Arrange
var expectedCharacters = new List<char>();
// Ascii values of all upper and lower case alphabets, numbers 0 - 9 and special characters till the max ascii value of 126
for (int i = 32; i <= 126; i++)
{
// convert to a character
char c = Convert.ToChar(i);
// add to the list
expectedCharacters.Add(c);
}
IAlphabetProvider provider = new EnglishAlphabetProvider();
// Act
var result = new string(provider.GetPrintableCharacters().ToArray());
// Assert
Assert.AreEqual(expectedCharacters, result);
}
public void ReturnPrintableCharacters()
{
// Arrange
var expectedCharacters = new List <char>();
// Ascii values of all upper and lower case alphabets, numbers 0 - 9 and special characters till the max ascii value of 126
for (int i = 32; i <= 126; i++)
{
// convert to a character
char c = Convert.ToChar(i);
// add to the list
expectedCharacters.Add(c);
}
IAlphabetProvider provider = new EnglishAlphabetProvider();
// Act
var result = new string(provider.GetPrintableCharacters().ToArray());
// Assert
Assert.AreEqual(expectedCharacters, result);
}
/// <summary>
/// Determines whether a string contains only printable characters.
/// </summary>
/// <param name="stringToCheck">The string to check.</param>
/// <returns>
/// <c>true</c> if the string contains only printable characters; otherwise, <c>false</c>.
/// </returns>
public static bool IsPrintableCharacter(this string stringToCheck)
{
if (string.IsNullOrEmpty(stringToCheck))
{
return false;
}
// get the alphabet provider
IAlphabetProvider provider = new EnglishAlphabetProvider();
// get the printable character set
var result = provider.GetPrintableCharacters().ToArray();
// return false if the character in the string is not found in printable character set
return stringToCheck.All(result.Contains);
}