/// <summary>
/// Reads an item property from an XML stream.
/// </summary>
private void ReadProperty(XmlTextReader reader)
{
// look up the property id.
PropertyDescription property = null;
if (reader.MoveToAttribute(PROPERTY_ID))
{
try
{
property = PropertyDescription.Find(new PropertyID(((int)System.Convert.ToInt32(reader.Value))));
}
catch
{
property = null;
}
}
// ignore invalid properties.
if (property == null)
{
return;
}
// read value.
object value = ReadValue(reader, property.Type);
switch (property.ID.Code)
{
case QUALITY: { m_quality = (Quality)value; break; }
case TIMESTAMP: { m_timestamp = (DateTime)value; break; }
case ACCESSRIGHTS: { m_accessRights = (accessRights)value; break; }
case SCANRATE: { m_scanRate = (float)value; break; }
case EUTYPE: { m_euType = (euType)((int)value + 1); break; }
case EUINFO: { m_euInfo = (string[])value; break; }
case HIGHEU: { m_maxValue = (double)value; break; }
case LOWEU: { m_minValue = (double)value; break; }
default:
{
m_properties[property.ID] = value;
break;
}
}
}
/// <summary>
/// Initializes the object with its item id and device.
/// </summary>
public CacheItem(string itemID, IDevice device)
{
if (itemID == null) throw new ArgumentNullException("itemID");
if (device == null) throw new ArgumentNullException("device");
m_itemID = itemID;
m_device = device;
m_datatype = (System.Type)ReadProperty(Property.DATATYPE);
m_euType = (euType)ReadProperty(Property.EUTYPE);
if (m_euType == euType.enumerated)
{
m_euInfo = (string[])ReadProperty(Property.EUINFO);
}
}
/// <summary>
/// Initializes the object with its item id and device.
/// </summary>
public SubscriptionItem(string itemID, Cache cache)
{
if (itemID == null) throw new ArgumentNullException("itemID");
if (cache == null) throw new ArgumentNullException("cache");
m_itemID = itemID;
m_cache = cache;
m_euType = (euType)m_cache.ReadProperty(m_itemID, Property.EUTYPE);
if (m_euType == euType.analog)
{
m_maxValue = (double)m_cache.ReadProperty(m_itemID, Property.HIGHEU);
m_minValue = (double)m_cache.ReadProperty(m_itemID, Property.LOWEU);
}
}
internal CacheItemSettings(string itemID, ushort ItemIndex, IDeviceIndexed Device)
{
lock (this)
{
m_itemID = itemID;
m_ItemIndex = ItemIndex;
m_device = Device;
m_datatype = (System.Type)CacheItem.ReadProperty(Property.DATATYPE, m_device, m_ItemIndex);
m_euType = (euType)CacheItem.ReadProperty(Property.EUTYPE, m_device, m_ItemIndex);
if (m_euType == euType.enumerated)
{
m_euInfo = (string[])CacheItem.ReadProperty(Property.EUINFO, m_device, m_ItemIndex);
}
}
}
/// <summary>
/// Reads an item property from an XML stream.
/// </summary>
private void ReadProperty(XmlTextReader reader)
{
// look up the property id.
PropertyDescription property = null;
if (reader.MoveToAttribute(PROPERTY_ID))
{
try
{
property = PropertyDescription.Find(new PropertyID(((int)System.Convert.ToInt32(reader.Value))));
}
catch
{
property = null;
}
}
// ignore invalid properties.
if (property == null)
{
return;
}
// read value.
object value = ReadValue(reader, property.Type);
switch (property.ID.Code)
{
case QUALITY: { m_quality = (Quality)value; break; }
case TIMESTAMP: { m_timestamp = (DateTime)value; break; }
case ACCESSRIGHTS: { m_accessRights = (accessRights)value; break; }
case SCANRATE: { m_scanRate = (float)value; break; }
case EUTYPE: { m_euType = (euType)((int)value+1); break; }
case EUINFO: { m_euInfo = (string[])value; break; }
case HIGHEU: { m_maxValue = (double)value; break; }
case LOWEU: { m_minValue = (double)value; break; }
default:
{
m_properties[property.ID] = value;
break;
}
}
}
/// <summary>
/// Writes the value of the specified item property.
/// </summary>
public Opc.IdentifiedResult Write(
PropertyID propertyID,
Opc.Da.ItemValue value)
{
// initialize result and validate property.
IdentifiedResult result = new IdentifiedResult();
result.ItemName = m_itemID;
result.ItemPath = null;
result.ResultID = ValidatePropertyID(propertyID, accessRights.writable);
result.DiagnosticInfo = null;
// handle value writes.
if (propertyID == Property.VALUE)
{
// copy value.
m_value = Opc.Convert.Clone(value.Value);
// update quality if specified.
if (value.QualitySpecified)
{
m_quality = value.Quality;
}
// update timestamp if specified.
if (value.TimestampSpecified)
{
m_timestamp = value.Timestamp;
}
// return results.
return result;
}
// lookup property description.
PropertyDescription property = PropertyDescription.Find(propertyID);
if (property == null)
{
result.ResultID = ResultID.Da.E_INVALID_PID;
return result;
}
// check datatype.
if (!property.Type.IsInstanceOfType(value.Value))
{
result.ResultID = ResultID.Da.E_BADTYPE;
return result;
}
// write non-value
switch (propertyID.Code)
{
// standard properties.
case DATATYPE: { m_datatype = (System.Type)value.Value; return result; }
case QUALITY: { m_quality = (Quality)value.Value; return result; }
case TIMESTAMP: { m_timestamp = (DateTime)value.Value; return result; }
case ACCESSRIGHTS: { m_accessRights = (accessRights)value.Value; return result; }
case SCANRATE: { m_scanRate = (float)value.Value; return result; }
case EUTYPE: { m_euType = (euType)value.Value; return result; }
case EUINFO: { m_euInfo = (string[])Opc.Convert.Clone(value.Value); return result; }
case HIGHEU: { m_maxValue = (double)value.Value; return result; }
case LOWEU: { m_minValue = (double)value.Value; return result; }
// other defined properties.
default:
{
if (!m_properties.Contains(propertyID))
{
result.ResultID = ResultID.Da.E_INVALID_PID;
return result;
}
m_properties[propertyID] = Opc.Convert.Clone(value.Value);
break;
}
}
// write complete.
return result;
}