/// <summary>
/// Creates a new persisted object with the specified primary key.
/// </summary>
/// <param name="type">The type of object to create.</param>
/// <param name="key">The user defined primary key</param>
/// <remarks>
/// This overload is for objects whose PrimaryKey is of type Identity or Guid (where ObjectServer handles primary key initialisation).
/// If the primary key type is Defined then this overload will throw an exception.
/// <para>
/// The actual objects returned from a call to Create are not of the defined type but of a
/// proxy class which sub-classes the persisted object and implements the abstract properties.
/// This is transparent as long as no access to the type occurs. If this is done then it is
/// nessecary to access the proxy's base type to get back to the defined type.
/// </para>
/// </remarks>
/// <returns>A newly initialised proxy for the specified type.</returns>
public ServerObject Create(Type type, object key)
{
if (type == null)
{
throw new ArgumentNullException("type", "type cannot be null.");
}
Trace.WriteLineIf(DebugOutput.Enabled, "Creating new ServerObject of type " + type.FullName);
TypeSchema schema = SchemaCache.Current.GetSchema(type);
ServerObject obj = Activator.CreateInstance(schema.Proxy) as ServerObject;
switch (schema.KeyType)
{
case PrimaryKeyType.Defined:
if (key == null)
{
throw new ObjectServerException(String.Format(CultureInfo.CurrentCulture, "{0} KeyType is PrimaryKey.Defined and no has been key passed to ObjectTransaction.Create", type.FullName));
}
Trace.WriteLineIf(DebugOutput.Enabled, "Setting key to " + key);
obj.Data.SetValue(schema.PrimaryKey.Property.Name, key);
break;
case PrimaryKeyType.Guid:
Guid guid = Guid.NewGuid();
Trace.WriteLineIf(DebugOutput.Enabled, "Setting key to " + guid);
obj.Data.SetValue(schema.PrimaryKey.Property.Name, guid);
break;
case PrimaryKeyType.Identity:
Trace.WriteLineIf(DebugOutput.Enabled, "Setting key to " + identityKey);
obj.Data.SetValue(schema.PrimaryKey.Property.Name, identityKey);
identityKey--;
break;
default:
throw new ObjectServerException("Invalid PrimaryKeyType found.");
}
;
foreach (PropertySchema property in schema.PropertySchemas)
{
if (property.CanBeNull)
{
obj.Data.SetValue(property.Property.Name, property.NullValue);
}
}
obj.State = ObjectState.Added;
obj.SetTransaction(this);
objectCache.Add(obj);
obj.PromptEvent(EventType.Created);
obj.PromptEvent(EventType.Initialised);
return(obj);
}
/// <summary>
/// Retrieves an object from the data source of the specified type with the specified primary key.
/// </summary>
/// <remarks>
/// Selects a single object from the data source using the given key to locate the values. If no values exist in the data source then Select returns null.
/// <para>
/// The actual objects returned from a call to Select are not of the defined type but of a
/// proxy class which sub-classes the persisted object and implements the abstract properties.
/// This is transparent as long as no access to the type occurs. If this is done then it is
/// nessecary to access the proxy's base type to get back to the defined type.
/// </para>
/// </remarks>
/// <param name="type">The type of object to create.</param>
/// <param name="key">The primary key which to select the object in the data source.</param>
/// <returns>A newly initialised proxy for the specified type and with the values given from the data source for the specified primary key.</returns>
public ServerObject Select(Type type, object key)
{
if (type == null)
{
throw new ArgumentNullException("type", "type cannot be null.");
}
if (key == null)
{
return(null);
}
Trace.WriteLineIf(DebugOutput.Enabled, "Selecting ServerObject of type " + type.FullName);
ServerObject obj = objectCache.Get(type, key);
if (obj != null)
{
return(obj);
}
try
{
adapter.Open();
obj = adapter.Select(type, key);
}
finally
{
adapter.Close();
}
if (obj == null)
{
Trace.WriteLineIf(DebugOutput.Enabled, "No object found returning null");
return(null);
}
obj.State = ObjectState.Unchanged;
obj.SetTransaction(this);
objectCache.Add(obj);
obj.PromptEvent(EventType.Initialised);
return(obj);
}
