protected virtual void InitList( Type viaType, params Type[] relationTypes )
{
if( listType == GentleListType.StandAlone )
{
broker.RetrieveList( containedMap.Type, this );
}
else if( listType == GentleListType.OneToMany )
{
// no relation objects for 1:n relationships
viaInstances = null;
mappings = containedMap.GetForeignKeyMappings( parentMap, true );
if( mappings.Count == 0 )
{
mappings = viaMap.GetForeignKeyMappings( parentMap, false );
}
Check.Verify( mappings.Count > 0, Error.DeveloperError,
"The type {0} does not contain a foreign key reference to type {1}.",
parentMap.Type, containedMap.Type );
Check.Verify( mappings.Count == 1, Error.NotImplemented,
"GentleList for 1:n relations can not be used with composite keys." );
// populate self with any existing entries matching the current parent
Key key = new Key( parentMap.Type, true );
IDictionaryEnumerator iterator = mappings.GetEnumerator();
while( iterator.MoveNext() )
{
// construct a key to read the data; first obtain the referenced value from
// the parent object (this is the constraint value used in the select)
FieldMap fm = iterator.Value as FieldMap;
object referencedValue = fm.GetValue( parent );
// if class references self make sure to pick the outgoing column
if( containedMap.Type == parentMap.Type && ! fm.IsForeignKey )
{
fm = iterator.Key as FieldMap;
}
key[ fm.MemberName ] = referencedValue;
}
broker.RetrieveList( containedMap.Type, key, this );
}
else if( listType == GentleListType.ManyToMany )
{
// create relation for n:m management
Type[] relatedTypes = Merge( containedMap.Type, relationTypes );
viaInstances = new GentleRelation( broker, viaType, parent, relatedTypes );
// populate the list with any existing entries matching the current relation entries
ObjectMap viaMap = ObjectFactory.GetMap( broker, viaType );
SqlBuilder sb = new SqlBuilder( broker, StatementType.Select, containedMap.Type );
// assume the relation object is the child, i.e. refers to the contained type
mappings = viaMap.GetForeignKeyMappings( containedMap, true );
if( mappings.Count == 0 )
{
mappings = viaMap.GetForeignKeyMappings( containedMap, false );
}
Check.Verify( mappings.Count > 0, Error.DeveloperError,
"The type {0} does not contain a foreign key reference to type {1}.",
viaMap.Type, containedMap.Type );
Check.Verify( mappings.Count == 1, Error.NotImplemented,
"GentleList for n:m relations can not be used with composite keys." );
// verify that references point to unique instance
//Check.Verify( mappings.Count == parentMap.PrimaryKeyCount, Error.DeveloperError,
// "The number of fields ({0}) referencing {1} from {2} must equal the primary key count ({3}).",
// mappings.Count, parentMap.Type, containedMap.Type, parentMap.PrimaryKeyCount );
if( viaInstances.Count > 0 )
{
foreach( FieldMap remote in mappings.Keys )
{
FieldMap local = (FieldMap) mappings[ remote ];
// viaMap.GetForeignKeyFieldMap( containedMap.Type, local.PropertyName );
sb.AddConstraint( Operator.In, local.MemberName, viaInstances, remote.MemberName );
}
ObjectFactory.GetCollection( containedMap.Type, sb.GetStatement( true ).Execute(), this );
}
}
}
