= Topo Geometry =


A !TopoGeometry is a PostGIS type used to represent geometries defined
by Topological elements (Face,Edge,Node,!TopoGeometry).

Current code implements the !TopoGeometry using a class defined
under the topology schema (topology.!TopoGeometry). This has the
following fields:

 * topology_id integer
 * layer_id integer
 * id integer
 * type integer

The actual _definition_ of each !TopoGeometry is contained in the [wiki:TopologyTableRelation relation] table of the topology identified by "topology_id". The "relation" table contains a record for each component of each TopoGeometry. Interpretation of the component also requires looking at the [wiki:TopologyTableLayer topology.layer] table, which tells if element_type refers to primitive type (node, edge, face) or another layer (in case of hierarchical !TopoGeometry).

See [wiki:UsersWikiCreatingTopoGeometryObjects CreatingTopoGeometryObjects] for information on how to create a !TopoGeometry.

See [wiki:UsersWikiPostgisTopology PostgisTopology].