/// <summary>
/// Applies the index range and data encoding to the value.
/// </summary>
/// <param name="context">The context.</param>
/// <param name="indexRange">The index range.</param>
/// <param name="dataEncoding">The data encoding.</param>
/// <param name="value">The value.</param>
/// <returns></returns>
protected ServiceResult ApplyIndexRangeAndDataEncoding(
ISystemContext context,
NumericRange indexRange,
QualifiedName dataEncoding,
DataValue value)
{
if (StatusCode.IsBad(value.StatusCode))
{
return(value.StatusCode);
}
if (indexRange != NumericRange.Empty || !QualifiedName.IsNull(dataEncoding))
{
object valueToUpdate = value.Value;
ServiceResult result = BaseVariableState.ApplyIndexRangeAndDataEncoding(
context,
indexRange,
dataEncoding,
ref valueToUpdate);
if (ServiceResult.IsBad(result))
{
value.Value = null;
value.StatusCode = result.StatusCode;
return(result);
}
value.Value = valueToUpdate;
}
return(value.StatusCode);
}
/// <summary>
/// Generates a new value each time the value is read.
/// </summary>
private ServiceResult DoDeviceRead(
ISystemContext context,
NodeState node,
NumericRange indexRange,
QualifiedName dataEncoding,
ref object value,
ref StatusCode statusCode,
ref DateTime timestamp)
{
BaseVariableState variable = node as BaseVariableState;
if (variable == null)
{
return(ServiceResult.Good);
}
if (!SimulationActive.Value)
{
return(ServiceResult.Good);
}
TestDataSystem system = context.SystemHandle as TestDataSystem;
if (system == null)
{
return(StatusCodes.BadOutOfService);
}
try
{
value = system.ReadValue(variable);
statusCode = StatusCodes.Good;
timestamp = DateTime.UtcNow;
ServiceResult error = BaseVariableState.ApplyIndexRangeAndDataEncoding(
context,
indexRange,
dataEncoding,
ref value);
if (ServiceResult.IsBad(error))
{
statusCode = error.StatusCode;
}
return(ServiceResult.Good);
}
catch (Exception e)
{
return(new ServiceResult(e));
}
}
/// <summary>
/// Reads the value for the value attribute.
/// </summary>
protected override ServiceResult ReadValueAttribute(
ISystemContext context,
NumericRange indexRange,
QualifiedName dataEncoding,
ref object value,
ref DateTime sourceTimestamp)
{
value = m_value;
ServiceResult result = ServiceResult.Good;
VariableCopyPolicy copyPolicy = VariableCopyPolicy.CopyOnRead;
// use default behavoir.
if (OnSimpleReadValue != null)
{
result = OnSimpleReadValue(
context,
this,
ref value);
if (ServiceResult.IsBad(result))
{
return(result);
}
copyPolicy = VariableCopyPolicy.Never;
}
else
{
// check if a valid value exists.
if (value == null)
{
return(StatusCodes.BadAttributeIdInvalid);
}
}
// apply the index range and encoding.
result = BaseVariableState.ApplyIndexRangeAndDataEncoding(context, indexRange, dataEncoding, ref value);
if (ServiceResult.IsBad(result))
{
return(result);
}
// copy returned value.
if (copyPolicy == VariableCopyPolicy.CopyOnRead)
{
value = Utils.Clone(value);
}
return(result);
}
private ServiceResult ApplyIndexRangeAndDataEncoding(
ISystemContext context,
ReadValueId nodeToRead,
DataValue value)
{
if (StatusCode.IsBad(value.StatusCode))
{
return(value.StatusCode);
}
if (nodeToRead.ParsedIndexRange != NumericRange.Empty || !QualifiedName.IsNull(nodeToRead.DataEncoding))
{
if (nodeToRead.AttributeId != Attributes.Value && !QualifiedName.IsNull(nodeToRead.DataEncoding))
{
return(StatusCodes.BadDataEncodingInvalid);
}
object valueToUpdate = value.Value;
ServiceResult result = BaseVariableState.ApplyIndexRangeAndDataEncoding(
context,
nodeToRead.ParsedIndexRange,
nodeToRead.DataEncoding,
ref valueToUpdate);
if (ServiceResult.IsBad(result))
{
bool useXml = nodeToRead.DataEncoding.Name == DefaultXml;
if (!useXml &&
!string.IsNullOrEmpty(nodeToRead.DataEncoding.Name) &&
nodeToRead.DataEncoding.Name != DefaultBinary)
{
result = StatusCodes.BadDataEncodingInvalid;
}
value.Value = null;
value.StatusCode = result.StatusCode;
return(result);
}
value.Value = valueToUpdate;
}
return(value.StatusCode);
}