/// <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>
/// 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>
/// <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));
}
