[Mapserver-dev] OGC ServiceExceptions and invalid layers

[Yewondwossen Assefa]

Here is the current status for OCG filter encoding support :


Spatial Capabilities Filters :

    - BBOX : supported

    - Equals : (compares if 2 geometries are equal) : Not suooprted but 
could be easliy added to mapserver.

    - Disjoint : (opposite to bbox and exclude element that intersects 
the query shape) Not supported. We need to add functions in mapserver 
that returns shapes that only intersects a certain query geometry and 
then we would be able to support it

     - Intersects : Not supported (see comments above)

      - Touches : Not supported (Touches definition differ depending on 
the geometry it refers to but basically it means the edge of one 
geometry touches the other geometry without crossing it)

	
      - Within	Not support : Elements are inside the querieng shape when 
It is a polygon, and when It is a line, elements are of linear types and 
the segnments are a subset of the querying shape.

      - Contain : Not supported : opposite to Within

      - Overlaps	Not supported : The query shape and the queried 
elements are of the same geometry. They have a common intersection.

      - Beyond	and DWithin : Not supported : The spatial operators 
DWithin and Beyond test whether the value of a geometric property is 
within or beyond a specified distance of the specified geometry.
This could be with the current mapserver code woth point query and a 
buffer but needs some works for other type of geometries


Scalar Capabilities	
	
Logical Operators	
       - And	: Supprted
        - Or	: Supported
        - Not : Supported

Comparison Operators:
   	PropertyIsEqualTo (=)	Yes
	PropertyIsNotEqualTo (<>)	Yes
	PropertyIsLessThan (<)	Yes
	PropertyIsGreaterThan (>)	Yes
	PropertyIsLessThanOrEqualTo (<=)	Yes
	PropertyIsGreaterThanOrEqualTo (>=)	Yes
	PropertyIsLike	Yes
	PropertyIsBetween (range)	Yes
	PropertyIsNull	No

  Limitiations with the comaparison operators :
     - we do not support in mapserver comparasion >, <, <=, <= on 
alphanumeric values.
	

Later,


Daniel Morissette wrote:

> Steve Lime wrote:
> 
>> Has anyone mapped OGC filters to MapServer queries explicitly? If so I'd
>> love
>> to see the list and know where the gaps are. Many may already be doable
>> or
>> easily added.
>>
> 
> Yes, Assefa has done that in 4.1... we really need to update everyone on 
> what we're doing... what he's done is mapping of OGC filters to 
> MapServer expressions, and then specifically for the WFS he convert WFS 
> requests with filters to MapServer queries.
> 
> Assefa has a list of filter types that are supported and not supported. 
>  I'll let him follow up on that.
> 

-- 
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Assefa Yewondwossen
Software Analyst

Email: assefa at dmsolutions.ca
http://www.dmsolutions.ca/

Phone: (613) 565-5056 (ext 14)
Fax:   (613) 565-0925
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