/// <summary>
/// Gets or creates data object depending on whether entity object
/// contains associated data object.
/// </summary>
/// <param name="context">DataObjectContext object.</param>
/// <param name="entity">Entity object.</param>
/// <returns>Generic data object.</returns>
public static T GetOrCreateDataObject <T>(DataObjectContext context,
EntityObject entity)
where T : DataObject
{
Debug.Assert(entity != null);
// get associated data object
IWrapDataAccess dataAccess = entity as IWrapDataAccess;
if (dataAccess == null)
{
throw new DataException(Properties.Messages.Error_GetWrapDataObjectFailed);
}
T obj = GetDataObject(entity) as T;
if (obj == null)
{
// associated object does not exist, create it
obj = context.CreateObject <T>(entity);
// associate object with entity
dataAccess.DataObject = obj;
}
return(obj);
}
/// <summary>
/// Gets data object associated with specified entity object.
/// </summary>
/// <param name="entity">
/// Entity object.
/// </param>
/// <returns>
/// Data object or null if there is no data object associated
/// with specified entity.
/// </returns>
public static DataObject GetDataObject(EntityObject entity)
{
Debug.Assert(entity != null);
DataObject dataObject = null;
IWrapDataAccess dataAccess = entity as IWrapDataAccess;
dataObject = (dataAccess != null) ? dataAccess.DataObject : null;
return(dataObject);
}
///////////////////////////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// Initializes a new instance of the <c>DataObject</c> class.
/// </summary>
protected DataObject(EntityObject entity)
{
Debug.Assert(entity != null);
_InitValidation();
// set entity's data object reference
IWrapDataAccess wda = entity as IWrapDataAccess;
if (wda == null)
{
Debug.Assert(false, "Entity object does not implement IWrapDataAccess.");
}
wda.DataObject = this;
_entity = entity;
}
