[postgis-tickets] [PostGIS] #2144: totopoGeom have an extra arg to prevent addition of primitives to topology

[PostGIS]

#2144: totopoGeom have an extra arg to prevent addition of primitives to topology
-------------------------+--------------------------------------------------
 Reporter:  robe         |       Owner:  strk         
     Type:  enhancement  |      Status:  new          
 Priority:  medium       |   Milestone:  PostGIS 2.1.0
Component:  topology     |     Version:  trunk        
 Keywords:               |  
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 This is a request from Leo.  In writing the example, he realized I could
 screw up his topology network with my reckless use of toTopoGeom and I did
 by not getting my points quite right to line up with his topology.

 The scenario:
 You are the master maintainer of a topology for say a city or something
 and have meticulously laid out the topology that should account for all
 department topogeometry needs.

 Some reckless person in department A, comes by and creates a topogeometry
 with toTopoGeom because his/her topogeometry which should have snapped to
 existing edges, did not.  Now you have extra annoying nodes in your
 topology.

 That reckless person may very well be you. You want the totopoGeom not to
 do you favors by creating new primitives if you know all the topos you are
 adding should be able to use the edges,nodes, and faces already existing
 in your topology.

 So after discussion, proposed solution is to add an extra proto to
 toTopoGeom that prevents creation of new primitives and if a topogeometry
 can't be created without adding a primitive, it should throw an error.

 So basically:

 change this existing proto:

 {{{
 toTopoGeom(geometry geom, varchar toponame, integer layer_id, float8
 tolerance);
 }}}


 {{{
 toTopoGeom(geometry geom, varchar toponame, integer layer_id, float8
 tolerance, allow_primitive_creation = true);
 }}}

 He wanted it to default to false, but since we are asking for this in a
 minor, we can't change that behavior without screwing up some people.

-- 
Ticket URL: <http://trac.osgeo.org/postgis/ticket/2144>
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