[Mapserver-users] SLD Filters (boolean operators)

[Yewondwossen Assefa]

Jeremy,

  The <OR> operator takes exactly 2 arguments, so It is not possible to 
have more that 2. But you can combine several OR statements to do what 
you need. For example a filter like this  <OR><OR>A B</OR>C</OR> is 
equivalent to  ((A OR B) OR C).

Later,
Jeremy Wiebe wrote:
> Hi there,  (sorry about the previous email from me, slipped with the send
> button.  :-(   )
> 
> Can anyone tell me if it is possible to group a sequence of <OR> operators
> in an SLD filter expression with MapServer?
> 
> I'm working on filtering a list of points and displaying the matches with
> one symbol and the rest with another symbol.   From the Filter Encoding
> Implementation Specification it seems that it should be possible to do at
> least 2 rules in an <OR> statement, but it is unclear if you can have more
> than that within an <OR>...   
> 
> The SLD I figured out is as follows: (The problem I have with it is it grows
> quite fast when there are lots of points to match)
> 
> <StyledLayerDescriptor version="1.0.0">
>   <NamedLayer>
>     <Name>property</Name>
>     <UserStyle>
>       <Title>PropertyFilter</Title>
>       <FeatureTypeStyle>
>         <Rule>
>           <Filter>
>             <PropertyIsEqualTo>
>               <PropertyName>PROPERTY_ID</PropertyName>
>               <Literal>101643</Literal>
>             </PropertyIsEqualTo>
>           </Filter>
>           <PointSymbolizer>
>             <Geometry>
>               <PropertyName>locatedAt</PropertyName>
>             </Geometry>
>             <Graphic>
>               <Mark>
>                 <WellKnownName>star</WellKnownName>
>                 <Fill>
>                   <CssParameter name="fill">#00ffff</CssParameter>
>                 </Fill>
>               </Mark>
>               <Size>25.0</Size>
>             </Graphic>
>           </PointSymbolizer>
>         </Rule>
>         <Rule>
>           <Filter>
>             <PropertyIsEqualTo>
>               <PropertyName>PROPERTY_ID</PropertyName>
>               <Literal>101005</Literal>
>             </PropertyIsEqualTo>
>           </Filter>
>           <PointSymbolizer>
>             <Geometry>
>               <PropertyName>locatedAt</PropertyName>
>             </Geometry>
>             <Graphic>
>               <Mark>
>                 <WellKnownName>star</WellKnownName>
>                 <Fill>
>                   <CssParameter name="fill">#00ffff</CssParameter>
>                 </Fill>
>               </Mark>
>               <Size>25.0</Size>
>             </Graphic>
>           </PointSymbolizer>
>         </Rule>
>         <Rule>
>           <ElseFilter />
>           <PointSymbolizer>
>             <Geometry>
>               <PropertyName>locatedAt</PropertyName>
>             </Geometry>
>             <Graphic>
>               <Mark>
>                 <WellKnownName>circle</WellKnownName>
>                 <Fill>
>                   <CssParameter name="fill">#fff798</CssParameter>
>                 </Fill>
>               </Mark>
>               <Size>15</Size>
>             </Graphic>
>           </PointSymbolizer>
>         </Rule>
>       </FeatureTypeStyle>
>     </UserStyle>
>   </NamedLayer>
> </StyledLayerDescriptor>
> 
> Now, what I'd like to be able to do is:
> 
> <StyledLayerDescriptor version="1.0.0">
>   <NamedLayer>
>     <Name>property</Name>
>     <UserStyle>
>       <Title>PropertyFilter</Title>
>       <FeatureTypeStyle>
>         <Rule>
>           <Filter>
>             <OR>
>               <PropertyIsEqualTo>
>                 <PropertyName>PROPERTY_ID</PropertyName>
>                 <Literal>101643</Literal>
>               </PropertyIsEqualTo>
>               <PropertyIsEqualTo>
>                 <PropertyName>PROPERTY_ID</PropertyName>
>                 <Literal>101005</Literal>
>               </PropertyIsEqualTo>
>               <PropertyIsEqualTo>
>                .... and so on... 
>               </PropertyIsEqualTo>
>             </OR>
>           </Filter>
>           <PointSymbolizer>
>             <Geometry>
>               <PropertyName>locatedAt</PropertyName>
>             </Geometry>
>             <Graphic>
>               <Mark>
>                 <WellKnownName>star</WellKnownName>
>                 <Fill>
>                   <CssParameter name="fill">#00ffff</CssParameter>
>                 </Fill>
>               </Mark>
>               <Size>25.0</Size>
>             </Graphic>
>           </PointSymbolizer>
>         </Rule>
>         <Rule>
>           <ElseFilter />
>           <PointSymbolizer>
>             <Geometry>
>               <PropertyName>locatedAt</PropertyName>
>             </Geometry>
>             <Graphic>
>               <Mark>
>                 <WellKnownName>circle</WellKnownName>
>                 <Fill>
>                   <CssParameter name="fill">#fff798</CssParameter>
>                 </Fill>
>               </Mark>
>               <Size>15</Size>
>             </Graphic>
>           </PointSymbolizer>
>         </Rule>
>       </FeatureTypeStyle>
>     </UserStyle>
>   </NamedLayer>
> </StyledLayerDescriptor>
> 
> Jeremy Wiebe
> Application Developer
> Linnet - The Land Systems Company 
> 1600-444 St. Mary Avenue,  Winnipeg, Manitoba, Canada, R3C 3T1
> Tel: 1-204-957-6452  Fax: 1-204-957-7568  email: jwiebe at linnet.ca
> http://www.linnet.ca 
> 
> _______________________________________________
> Mapserver-users mailing list
> Mapserver-users at lists.gis.umn.edu
> http://lists.gis.umn.edu/mailman/listinfo/mapserver-users
> 


-- 
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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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