[mapguide-trac] #2001: Spatial Contexts are overridden incorrectly

[MapGuide Open Source]

#2001: Spatial Contexts are overridden incorrectly
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   Reporter:  jng              |       Owner:       
       Type:  defect           |      Status:  new  
   Priority:  high             |   Milestone:  2.4  
  Component:  Feature Service  |     Version:  2.2.0
   Severity:  blocker          |    Keywords:       
External_id:                   |  
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 Consider this example output (GetSpatialContexts) of an ODBC feature
 source with no coordinate system overrides:

 {{{
 <?xml version="1.0" encoding="UTF-8"?>
 <FdoSpatialContextList>
   <ProviderName>OSGeo.ODBC.3.5</ProviderName>
   <SpatialContext IsActive="false">
     <Name>Default</Name>
     <Description/>
     <CoordinateSystemName/>
     <CoordinateSystemWkt/>
     <ExtentType>Static</ExtentType>
     <Extent>
       <LowerLeftCoordinate>
         <X>-2000000</X>
         <Y>-2000000</Y>
       </LowerLeftCoordinate>
       <UpperRightCoordinate>
         <X>2000000</X>
         <Y>2000000</Y>
       </UpperRightCoordinate>
     </Extent>
     <XYTolerance>0.001000</XYTolerance>
     <ZTolerance>0.001000</ZTolerance>
   </SpatialContext>
 </FdoSpatialContextList>
 }}}

 Here's what the output looks like with a coordinate system override on the
 "Default" spatial context

 {{{
 <?xml version="1.0" encoding="UTF-8"?>
 <FdoSpatialContextList>
   <ProviderName>OSGeo.ODBC.3.5</ProviderName>
   <SpatialContext IsActive="false">
 <Name>GEOGCS["LL84",DATUM["WGS84",SPHEROID["WGS84",6378137.000,298.25722293]],PRIMEM["Greenwich",0],UNIT["Degree",0.01745329251994]]</Name>
     <Description>This coordinate system has been overridden.</Description>
     <CoordinateSystemName>Default</CoordinateSystemName>
 <CoordinateSystemWkt>GEOGCS["LL84",DATUM["WGS84",SPHEROID["WGS84",6378137.000,298.25722293]],PRIMEM["Greenwich",0],UNIT["Degree",0.01745329251994]]</CoordinateSystemWkt>
     <ExtentType>Static</ExtentType>
     <Extent>
       <LowerLeftCoordinate>
         <X>-2000000</X>
         <Y>-2000000</Y>
       </LowerLeftCoordinate>
       <UpperRightCoordinate>
         <X>2000000</X>
         <Y>2000000</Y>
       </UpperRightCoordinate>
     </Extent>
     <XYTolerance>0.001000</XYTolerance>
     <ZTolerance>0.001000</ZTolerance>
   </SpatialContext>
 </FdoSpatialContextList>
 }}}

 This output is wrong because the name component of the spatial context is
 the unique key by which Geometry Properties in a class definition use to
 look up a particular spatial context (via its SpatialContextAssociation).

 The most evident symptom of this issue is attempting to preview such a
 Feature Class from a Feature Source (w/ overrides) via the schema report.
 The preview will fail because it tries to fetch extents via the geometry
 property's spatial context association. Because the CS override clobbers
 the name, no matching spatial context is found, resulting in a empty
 extent, therefore no preview is possible.

 Similarly, any function that involves spatial context lookup via it's
 geometry property is also affected by this incorrect overrides.

 The fix is simply to '''never modify the name of the spatial context''' if
 overrides are to be applied

-- 
Ticket URL: <http://trac.osgeo.org/mapguide/ticket/2001>
MapGuide Open Source <http://mapguide.osgeo.org/>
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