[GEOS-7732] CSS: stroke-offset does not accept expressions - JIRA

Details

Type: Bug
Status: Closed
Priority: Medium
Resolution: Fixed
Affects Version/s: 2.9.1
Fix Version/s: 2.9.3, 2.10.1
Component/s: CSS
Labels:
None
Environment:

Amazon Linux (Linux 4.4.19-29.55.amzn1.x86_64 x86_64)
Oracle JRE 1.8.0_74
Tomcat 7.0.70

Triage:
- sprint

Description

Hello,
I was trying to create a style visualising traffic flows as stroke width on a bidirectional road network like the attached image.

I was trying to submit the following to CSS Styling extension (GeoServer 2.9.1)

* {
  stroke: #27b700;
  stroke-linecap: butt;  
  stroke-linejoin: bevel;  
  stroke-width : [ max(0.5, min(58.27, traffic_flow * 58.27 / 20000)) ];
  stroke-offset: [ -0.5 * max(0.5, min(58.27, traffic_flow * 58.27 / 20000)) - 1 ];
}

The CSS was accepted without validation errors but the generated SLD turned out to be the following

<?xml version="1.0" encoding="UTF-8"?>
<sld:StyledLayerDescriptor xmlns="http://www.opengis.net/sld" xmlns:sld="http://www.opengis.net/sld" xmlns:gml="http://www.opengis.net/gml" xmlns:ogc="http://www.opengis.net/ogc" version="1.0.0"> 
  <sld:NamedLayer>
    <sld:Name>Default Styler</sld:Name> 
    <sld:UserStyle>
      <sld:Name>Default Styler</sld:Name>
      <sld:FeatureTypeStyle> 
        <sld:Rule>
          <sld:LineSymbolizer>
            <sld:Stroke>
              <sld:CssParameter name="stroke">#27b700</sld:CssParameter>
              <sld:CssParameter name="stroke-linejoin">bevel</sld:CssParameter>
              <sld:CssParameter name="stroke-width">
                <ogc:Function name="max">
                  <ogc:Literal>0.5</ogc:Literal>
                  <ogc:Function name="min">
                    <ogc:Literal>58.27</ogc:Literal>
                    <ogc:Div>
                      <ogc:Mul>
                        <ogc:PropertyName>traffic_flow</ogc:PropertyName>
                        <ogc:Literal>58.27</ogc:Literal>
                      </ogc:Mul>
                      <ogc:Literal>20000</ogc:Literal>
                    </ogc:Div>
                  </ogc:Function>
                </ogc:Function>
              </sld:CssParameter> 
            </sld:Stroke>
            <sld:PerpendicularOffset>((-0.5*max([0.5], [min([58.27], [((traffic_flow*58.27)/20000)])]))-1)</sld:PerpendicularOffset> 
          </sld:LineSymbolizer> 
        </sld:Rule> 
        <sld:VendorOption name="ruleEvaluation">first</sld:VendorOption>
      </sld:FeatureTypeStyle> 
    </sld:UserStyle>
  </sld:NamedLayer>
</sld:StyledLayerDescriptor>

You will see that the interpretor just put the stroke-offset to PerpendicularOffset without any translation, not even wrapped in ogc:Literal tag. Consequently, GeoSever throws an error when this SLD is applied.

The correct SLD should be like this. This has worked without errors as GeoServer allows expressions for PerpendicularOffsett.

<?xml version="1.0" encoding="UTF-8"?>
<sld:StyledLayerDescriptor xmlns="http://www.opengis.net/sld" xmlns:sld="http://www.opengis.net/sld" xmlns:gml="http://www.opengis.net/gml" xmlns:ogc="http://www.opengis.net/ogc" version="1.0.0"> 
  <sld:NamedLayer>
    <sld:Name>Default Styler</sld:Name> 
    <sld:UserStyle>
      <sld:Name>Default Styler</sld:Name>
      <sld:FeatureTypeStyle> 
        <sld:Rule>
          <sld:LineSymbolizer>
            <sld:Stroke>
              <sld:CssParameter name="stroke">#27b700</sld:CssParameter>
              <sld:CssParameter name="stroke-linejoin">bevel</sld:CssParameter>
              <sld:CssParameter name="stroke-width">
                <ogc:Function name="max">
                  <ogc:Literal>0.5</ogc:Literal>
                  <ogc:Function name="min">
                    <ogc:Literal>58.27</ogc:Literal>
                    <ogc:Div>
                      <ogc:Mul>
                        <ogc:PropertyName>traffic_flow</ogc:PropertyName>
                        <ogc:Literal>58.27</ogc:Literal>
                      </ogc:Mul>
                      <ogc:Literal>20000</ogc:Literal>
                    </ogc:Div>
                  </ogc:Function>
                </ogc:Function>
              </sld:CssParameter> 
            </sld:Stroke>
            <sld:PerpendicularOffset>
              <ogc:Add> 
                <ogc:Mul> 
                  <ogc:Literal>-0.5</ogc:Literal>
                  <ogc:Function name="max">
                    <ogc:Literal>0.5</ogc:Literal> 
                    <ogc:Function name="min"> 
                      <ogc:Literal>58.27</ogc:Literal> 
                      <ogc:Div> 
                        <ogc:Mul> 
                          <ogc:PropertyName>traffic_flow</ogc:PropertyName> 
                          <ogc:Literal>58.27</ogc:Literal> 
                        </ogc:Mul> 
                        <ogc:Literal>20000</ogc:Literal>
                      </ogc:Div> 
                    </ogc:Function> 
                  </ogc:Function>
                </ogc:Mul> 
                <ogc:Literal>-1</ogc:Literal> 
              </ogc:Add> 
            </sld:PerpendicularOffset> 
          </sld:LineSymbolizer> 
        </sld:Rule> 
        <sld:VendorOption name="ruleEvaluation">first</sld:VendorOption>
      </sld:FeatureTypeStyle> 
    </sld:UserStyle>
  </sld:NamedLayer>
</sld:StyledLayerDescriptor>

I think it is worth to enable users to use expressions in stroke-offset.
Please note that I have also tried this in the refined new style editor (the default one, not the extension one) but things were the same.

Many thanks,

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08/Sep/16 2:52 PM

Issue links

is blocked by

GEOT-5557 SLDTransformer does not correctly encode expressions in line symbolizer perpendicular offset

Closed

Activity

People

Assignee:

Andrea Aime

Reporter:

Go Sato

Votes:

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Watchers:

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Dates

Created:

08/Sep/16 2:56 PM

Updated:

15/Feb/17 12:47 PM

Resolved:

28/Oct/16 5:16 PM