Support for Puntal output in topology.AsTopoJSON

Closes #3343 git-svn-id: http://svn.osgeo.org/postgis/trunk@14298 b70326c6-7e19-0410-871a-916f4a2858ee

Author: Sandro Santilli

doc/extras_topology.xml

@@ -3266,11 +3266,16 @@ in the "edgeMapTable" table.
  </note>
 
 <para>
-A full TopoJSON document will be need to contain, in addition to the snippets returned by this function, the actual arcs plus some headers. See the <ulink url="http://github.com/mbostock/topojson/wiki/Specification">TopoJSON specification</ulink>.
+A full TopoJSON document will be need to contain, in
+addition to the snippets returned by this function,
+the actual arcs plus some headers. See the <ulink
+url="http://github.com/mbostock/topojson-specification/blob/master/README.md"
+>TopoJSON specification</ulink>.
 </para>
 
  <!-- use this format if new function -->
  <para>Availability: 2.1.0 </para>
+ <para>Enhanced: 2.2.1 added support for puntal inputs</para>
 </refsection>
 
 

topology/sql/export/TopoJSON.sql.in

@@ -22,6 +22,9 @@
 --
 -- text AsTopoJSON(TopoGeometry, edgeMapTable)
 --
+-- Format specification here:
+-- http://github.com/mbostock/topojson-specification/blob/master/README.md
+--
 -- }{
 CREATE OR REPLACE FUNCTION topology.AsTopoJSON(tg topology.TopoGeometry, edgeMapTable regclass)
  RETURNS text AS
@@ -56,12 +59,12 @@ BEGIN
  SELECT name FROM topology.topology into toponame
  WHERE id = tg.topology_id;
 
- -- Puntual TopoGeometry
+ -- TODO: implement scale ?
+
+ -- Puntal TopoGeometry, simply delegate to AsGeoJSON
  IF tg.type = 1 THEN
- -- TODO: implement scale ?
- --json := ST_AsGeoJSON(topology.Geometry(tg));
- --return json;
- RAISE EXCEPTION 'TopoJSON export does not support puntual objects';
+ json := ST_AsGeoJSON(topology.Geometry(tg));
+ return json;
  ELSIF tg.type = 2 THEN -- lineal
 
  FOR rec IN SELECT (ST_Dump(topology.Geometry(tg))).geom

topology/test/regress/topojson.sql

@@ -92,5 +92,10 @@ SELECT 'A3-vanilla', feature_name, topology.AsTopoJSON(feature, null)
  WHERE feature_name IN ('P6')
  ORDER BY feature_name;
 
+SELECT 'P1-vanilla', feature_name, topology.AsTopoJSON(feature, null)
+ FROM features.traffic_signs
+ WHERE feature_name IN ('S2')
+ ORDER BY feature_name;
+
 SELECT topology.DropTopology('city_data');
 DROP SCHEMA features CASCADE;

topology/test/regress/topojson_expected

@@ -49,4 +49,5 @@ E33
 E34
 E35
 A3-vanilla|P6|{ "type": "MultiPolygon", "arcs": [[[-33],[30,25],[1]],[[-34],[34]]]}
+P1-vanilla|S2|{"type":"MultiPoint","coordinates":[[35,14]]}
 Topology 'city_data' dropped