/// <summary>
/// Runs all ArgumentTransformationAttributes that are specified in the Attributes
/// collection on the given value in the order that they are in the collection.
/// </summary>
/// <param name="attributes">
/// The attributes to use to transform the value.
/// </param>
/// <param name="value">
/// The value to be transformed.
/// </param>
/// <returns>
/// The transformed value.
/// </returns>
/// <exception cref="ArgumentTransformationMetadataException">
/// If the argument transformation fails.
/// </exception>
internal static object TransformValue(IEnumerable <Attribute> attributes, object value)
{
Diagnostics.Assert(attributes != null, "caller to verify attributes is not null");
object result = value;
// Get an EngineIntrinsics instance using the context of the thread.
ExecutionContext context = Runspaces.LocalPipeline.GetExecutionContextFromTLS();
EngineIntrinsics engine = null;
if (context != null)
{
engine = context.EngineIntrinsics;
}
foreach (Attribute attribute in attributes)
{
ArgumentTransformationAttribute transformationAttribute =
attribute as ArgumentTransformationAttribute;
if (transformationAttribute != null)
{
result = transformationAttribute.TransformInternal(engine, result);
}
}
return(result);
}
/// <summary>
/// Validates and performs any transformations that the new attribute
/// implements.
/// </summary>
/// <param name="item">
/// The new attribute to be added to the collection.
/// </param>
/// <returns>
/// The new variable value. This may change from the original value if the
/// new attribute is an ArgumentTransformationAttribute.
/// </returns>
private object VerifyNewAttribute(Attribute item)
{
object variableValue = _variable.Value;
// Perform transformation before validating
ArgumentTransformationAttribute argumentTransformation = item as ArgumentTransformationAttribute;
if (argumentTransformation != null)
{
// Get an EngineIntrinsics instance using the context of the thread.
ExecutionContext context = Runspaces.LocalPipeline.GetExecutionContextFromTLS();
EngineIntrinsics engine = null;
if (context != null)
{
engine = context.EngineIntrinsics;
}
variableValue = argumentTransformation.TransformInternal(engine, variableValue);
}
if (!PSVariable.IsValidValue(variableValue, item))
{
ValidationMetadataException e = new ValidationMetadataException(
"ValidateSetFailure",
null,
Metadata.InvalidMetadataForCurrentValue,
_variable.Name,
((_variable.Value != null) ? _variable.Value.ToString() : string.Empty));
throw e;
}
return(variableValue);
}
