/// <summary>
/// Use the pipeline to process this FlowData instance and
/// populate the aspect data values.
/// </summary>
/// <exception cref="PipelineException">
/// Thrown if this flow data object has already been processed.
/// </exception>
/// <exception cref="ObjectDisposedException">
/// Thrown if the Pipeline has already been disposed.
/// </exception>
public void Process()
{
if (_processed)
{
throw new PipelineException(Messages.ExceptionFlowDataAlreadyProcessed);
}
_processed = true;
PipelineInternal.Process(this);
}
/// <summary>
/// Get the specified property as the specified type.
/// </summary>
/// <typeparam name="T">
/// The type to return the property value as
/// </typeparam>
/// <param name="propertyName">
/// The name of the property to get
/// </param>
/// <returns>
/// The property value
/// </returns>
/// <exception cref="PipelineException">
/// Thrown if this FlowData instance has not been processed yet.
/// </exception>
/// <exception cref="PipelineDataException">
/// Thrown if the requested property cannot be found or if multiple
/// flow elements use the same property name.
/// </exception>
/// <exception cref="InvalidCastException">
/// Thrown if property value cannot be cast to the requested type.
/// </exception>
/// <exception cref="KeyNotFoundException">
/// Thrown if property value is expected to be present but was not
/// found.
/// </exception>
public T GetAs <T>(string propertyName)
{
T result;
// Throw an error if the instance has not yet been processed.
if (_processed == false)
{
_logger.LogError(Messages.ExceptionFlowDataNotYetProcessed);
throw new PipelineException(Messages.ExceptionFlowDataNotYetProcessed);
}
var property = PipelineInternal.GetMetaDataForProperty(propertyName);
// Attempt to cast the property value object to the desired type.
// If this fails then log an error message and throw an exception.
try
{
result = (T)Get(property.Element.ElementDataKey)[property.Name];
}
catch (InvalidCastException)
{
string message = $"Failed to cast property '{propertyName}'" +
$" to '{typeof(T).Name}'. " +
$"Expected property type is '{property.Type.Name}'";
_logger.LogError(message);
throw;
}
catch (KeyNotFoundException)
{
string message = $"Property '{propertyName}' was not in " +
$"the data from '{property.Element.GetType().Name}' " +
$"as expected.";
_logger.LogError(message);
throw;
}
return(result);
}
