[postgis-tickets] [PostGIS] #472: Missing ST_IsValid for Geography Types

[PostGIS]

#472: Missing ST_IsValid for Geography Types
--------------------------+-----------------------------
  Reporter:  rfcmedia     |      Owner:  pramsey
      Type:  enhancement  |     Status:  new
  Priority:  medium       |  Milestone:  PostGIS Fund Me
 Component:  postgis      |    Version:  master
Resolution:               |   Keywords:
--------------------------+-----------------------------

Comment (by mschott):

 This is how I handle geography validity atm. Being aware that this may be
 resource intensive and that it may still fail e.g. if the object was
 projected in an st_intersect (where the best_srid is created for both
 objects together, afaik) with the respective documentation this might
 actually help some users. Be aware though that casting between geog and
 geom may introduce errors at a later stage. E.g. st_difference on two
 valid geoms casted to geog may produce invalid geogs when the resulting
 geom is casted back.


 {{{
 CREATE OR REPLACE FUNCTION {checkValidGeogFunc}(geography) RETURNS boolean
     AS 'SELECT
             st_isvalid(
                 ST_transform(
                     $1::geometry,
                     _ST_bestsrid($1)
                 )
             );'
     LANGUAGE SQL
     IMMUTABLE
     RETURNS NULL ON NULL INPUT;

 CREATE OR REPLACE FUNCTION {validateGeogFunc}(geography) RETURNS geography
     AS 'SELECT
             ST_transform(
                 st_multi(
                     st_collectionextract(
                         st_makevalid(
                             ST_transform(
                                 $1::geometry,
                                 _ST_bestsrid($1)
                             )
                         ),
                         3
                     )
                 ),
                 4326
             )::geography;'
     LANGUAGE SQL
     IMMUTABLE
     RETURNS NULL ON NULL INPUT;
 }}}

-- 
Ticket URL: <https://trac.osgeo.org/postgis/ticket/472#comment:5>
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