public async Task ValidateAsync(IValidatableViewModel context, PropertyInfo sender, bool validateAll)
{
this.Error.Clear();
for (int i = 0; i < this.Count; i++)
{
var item = this[i];
// Dont invoke these kind of validators
if (!ValidationHandler.IgnoreAlwaysValidate && !item.AlwaysValidate && sender == null && !validateAll)
{
continue;
}
var error = await item.ValidateAsync(sender, context);
if (!string.IsNullOrEmpty(error))
{
this.Error.Push(error);
if (!ValidationHandler.StopValidationOnError)
{
break;
}
}
}
}
/// <summary>
/// Invokes the validation on the specified context with the specified parameters
/// </summary>
/// <param name="sender">The property that invoked the validation</param>
/// <param name="context">The Viewmodel context that has to be validated</param>
/// <param name="propertyInfo">The <see cref="PropertyInfo"/> of the validated property</param>
/// <param name="value">The value of the property</param>
/// <returns>Has to return true on validation error otherwise false</returns>
protected override Task <bool> OnValidateAsync(PropertyInfo sender, IValidatableViewModel context, PropertyInfo propertyInfo, object value)
{
// if the value is null, then we should return a validation successfull, so that it is
// possible to have non mandatory inputs
if (value == null)
{
return(Task.FromResult(false));
}
if (this.value != null)
{
return(Task.FromResult(!Comparer.GreaterThanOrEqual(value, this.value)));
}
var otherProperty = context.GetType().GetPropertyEx(this.propertyName);
if (otherProperty == null)
{
throw new ArgumentException(string.Format("The property '{0}' was not found on '{1}'.", this.propertyName, context.GetType().FullName));
}
// Also same for this value
var comparisonValue = otherProperty.GetValue(context);
if (comparisonValue == null)
{
return(Task.FromResult(false));
}
return(Task.FromResult(!Comparer.GreaterThanOrEqual(value, comparisonValue)));
}
/// <summary>
/// Invokes the validation on the specified context with the specified parameters
/// </summary>
/// <param name="sender">The property that invoked the validation</param>
/// <param name="context">The Viewmodel context that has to be validated</param>
/// <param name="propertyInfo">The <see cref="PropertyInfo"/> of the validated property</param>
/// <param name="value">The value of the property</param>
/// <returns>Has to return true on validation error otherwise false</returns>
protected override Task <bool> OnValidateAsync(PropertyInfo sender, IValidatableViewModel context, PropertyInfo propertyInfo, object value)
{
if (this.isEnabledPropertyName != null && !this.IsEnabled(context, propertyInfo))
{
return(Task.FromResult(false));
}
if (value == null)
{
return(Task.FromResult(true));
}
if (propertyInfo.PropertyType == typeof(string))
{
return(Task.FromResult(string.IsNullOrEmpty(value.ToString())));
}
if (propertyInfo.PropertyType == typeof(bool))
{
return(Task.FromResult(!(bool)value));
}
if (value is IEnumerable && (value as IEnumerable).Operations().Count() == 0)
{
return(Task.FromResult(true));
}
if (propertyInfo.PropertyType == typeof(SecureString))
{
return(Task.FromResult((value as SecureString).Length == 0));
}
return(Task.FromResult(false));
}
/// <summary>
/// Occures on validation
/// <para/>
/// Can be used to modify the validation error message.
/// </summary>
/// <param name="errorMessage">The validation error message</param>
/// <param name="context">The Viewmodel context that has to be validated</param>
/// <returns>A modified validation error message</returns>
protected override string ValidationMessage(string errorMessage, IValidatableViewModel context)
{
var otherProperty = context.GetType().GetPropertyEx(this.otherProperty);
if (otherProperty == null)
{
return(errorMessage);
}
return(errorMessage.ToString(otherProperty.GetValue(context)));
}
/// <summary>
/// Invokes the validation on the specified context with the specified parameters
/// </summary>
/// <param name="sender">The property that invoked the validation</param>
/// <param name="context">The Viewmodel context that has to be validated</param>
/// <returns>Returns the error message if validation fails. Empty if successful</returns>
internal async Task <string> ValidateAsync(PropertyInfo sender, IValidatableViewModel context)
{
var value = this.propertyInfo.GetValue(context);
if (await this.OnValidateAsync(sender, context, propertyInfo, value))
{
return(this.ValidationMessage(Locale.Current[this.ErrorMessageKey], context));
}
return(string.Empty);
}
/// <summary>
/// Registers an <see cref="IValidationComponent"/> into the <see cref="ValidationContext"/>
/// of the specified <see cref="IValidatableViewModel"/>. Disposes and removes the
/// <see cref="IValidationComponent"/> from the <see cref="ValidationContext"/> when the
/// <see cref="ValidationHelper"/> is disposed.
/// </summary>
/// <param name="viewModel">The validatable view model holding a reference to the context.</param>
/// <param name="validation">The disposable validation component to register into the context.</param>
/// <typeparam name="TValidationComponent">The disposable validation component type.</typeparam>
/// <returns>The bindable validation helper holding the disposable.</returns>
private static ValidationHelper RegisterValidation <TValidationComponent>(
this IValidatableViewModel viewModel,
TValidationComponent validation)
where TValidationComponent : IValidationComponent, IDisposable
{
viewModel.ValidationContext.Add(validation);
return(new ValidationHelper(validation, Disposable.Create(() =>
{
viewModel.ValidationContext.Remove(validation);
validation.Dispose();
})));
}
/// <summary>
/// Invokes the validation on the specified context with the specified parameters
/// </summary>
/// <param name="sender">The property that invoked the validation</param>
/// <param name="context">The Viewmodel context that has to be validated</param>
/// <param name="propertyInfo">The <see cref="PropertyInfo"/> of the validated property</param>
/// <param name="value">The value of the property</param>
/// <returns>Has to return true on validation error otherwise false</returns>
protected override Task <bool> OnValidateAsync(PropertyInfo sender, IValidatableViewModel context, PropertyInfo propertyInfo, object value)
{
var strength = PasswordScore.Blank;
var password = string.Empty;
if (propertyInfo.PropertyType == typeof(string))
{
strength = CryptoUtils.GetPasswordScore(password);
}
return(Task.FromResult(strength == PasswordScore.Blank || strength == PasswordScore.VeryWeak || strength == PasswordScore.Weak));
}
/// <summary>
/// Invokes the validation on the specified context with the specified parameters
/// </summary>
/// <param name="sender">The property that invoked the validation</param>
/// <param name="context">The viewmodel context that has to be validated</param>
/// <param name="propertyInfo">The <see cref="PropertyInfo"/> of the validated property</param>
/// <param name="value">The value of the property</param>
/// <returns>Has to return true on validation error otherwise false</returns>
protected override async Task <bool> OnValidateAsync(PropertyInfo sender, IValidatableViewModel context, PropertyInfo propertyInfo, object value)
{
// if the value is null, then we should return a validation successfull, so that it is
// possible to have non mandatory inputs
if (value == null)
{
return(false);
}
var secondProperty = context.GetType().GetPropertyEx(this.otherProperty);
if (secondProperty == null)
{
return(true);
}
var secondValue = secondProperty.GetValue(context);
if (sender == null)
{
await context.ValidateAsync(propertyInfo, secondProperty.Name);
}
if (value is SecureString && (secondValue is SecureString || secondValue == null))
{
var ssa = value as SecureString;
var ssb = secondValue as SecureString;
if (ssa.Length == 0 && ssb == null)
{
return(true);
}
if (ssa.Length != 0 && ssb == null)
{
return(false);
}
return(ssa.IsEqualTo(ssb));
}
if (secondValue == null)
{
return(false);
}
return(!Comparer.Equals(value, secondValue));
}
/// <summary>
/// Invokes the validation on the specified context with the specified parameters
/// </summary>
/// <param name="sender">The property that invoked the validation</param>
/// <param name="context">The Viewmodel context that has to be validated</param>
/// <param name="propertyInfo">The <see cref="PropertyInfo"/> of the validated property</param>
/// <param name="value">The value of the property</param>
/// <returns>Has to return true on validation error otherwise false</returns>
protected override Task <bool> OnValidateAsync(PropertyInfo sender, IValidatableViewModel context, PropertyInfo propertyInfo, object value)
{
if (propertyInfo.PropertyType != typeof(string))
{
throw new ArgumentException("The StringLengthAttribute can only be applied to a string");
}
var str = value as string;
if (str == null)
{
return(Task.FromResult(true));
}
var length = str.Length;
return(Task.FromResult(length < this.minLength || length > this.maxLength));
}
/// <summary> /// Occures on validation /// <para/> /// Can be used to modify the validation error message. /// </summary> /// <param name="errorMessage">The validation error message</param> /// <param name="context">The Viewmodel context that has to be validated</param> /// <returns>A modified validation error message</returns> protected override string ValidationMessage(string errorMessage, IValidatableViewModel context) => errorMessage.ToString(minLength, maxLength);
/// <summary> /// Occures on validation /// <para/> /// Can be used to modify the validation error message. /// </summary> /// <param name="errorMessage">The validation error message</param> /// <param name="context">The Viewmodel context that has to be validated</param> /// <returns>A modified validation error message</returns> protected virtual string ValidationMessage(string errorMessage, IValidatableViewModel context) => errorMessage;
/// <summary> /// Invokes the validation on the specified context with the specified parameters /// </summary> /// <param name="sender">The property that invoked the validation</param> /// <param name="context">The Viewmodel context that has to be validated</param> /// <param name="propertyInfo">The <see cref="PropertyInfo"/> of the validated property</param> /// <param name="value">The value of the property</param> /// <returns>Has to return true on validation error otherwise false</returns> protected abstract Task <bool> OnValidateAsync(PropertyInfo sender, IValidatableViewModel context, PropertyInfo propertyInfo, object value);
