WMS Request sld& parameter has no effect

Question

I am trying to use dynamic styling by providing the sld& parameter in the WMS request. The parameter is pointing to a local file that is modified by a script. Like this: sld=file:///D:/testStyle.sld&.

The issue is that the layer is always displayed with the default style defined on GeoServer. Here is the content of the file:

<?xml version="1.0" encoding="UTF-8"?>
<StyledLayerDescriptor version="1.0.0" 
 xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd" 
 xmlns="http://www.opengis.net/sld" 
 xmlns:ogc="http://www.opengis.net/ogc" 
 xmlns:xlink="http://www.w3.org/1999/xlink" 
 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
  <NamedLayer>
    <Name>ne:testLayer</Name>
    <UserStyle>
      <Name>testStyle</Name>
      <Title>simple</Title>
      <FeatureTypeStyle>
        <Rule>
            <PointSymbolizer>
              <Graphic>
                <Mark>
                  <WellKnownName>circle</WellKnownName>
                  <Fill>
                    <CssParameter name="fill">#FF0000</CssParameter>
                  </Fill>
                </Mark>
              <Size>6</Size>
            </Graphic>
          </PointSymbolizer>
        </Rule>
      </FeatureTypeStyle>
    </UserStyle>
  </NamedLayer>
</StyledLayerDescriptor>

I have tried the following:

1. Omit the layers& parameter in the WMS request so I do not go into Library Mode. This works fine, but unfortunately I am constrained to use the layers& parameter in the request so this is not an option.
2. Using the layers& and sld& parameters in the WMS request. I am aware that this will trigger Library Mode. When I do this, the layer is displayed with the default style, not with the style defined in the SLD.
3. Using the layers&, sld&, styles=testStyle& parameters in the WMS request. When I do this I get an error that tells me the testStyle could not be found. (even though there are no typos)
4. Using the layers& and sld& parameters in the WMS and also adding the <IsDefault>1</IsDefault> tag in the UserStyle defined in the SLD. In this case, the layers is displayed again with the default style - defined in GeoServer.

The request I am using to preview the layer (only for point 3- since for the other points I just remove some of the parameters):

http://localhost:8080/geoserver/ne/wms?service=WMS&version=1.1.0&request=GetMap&layers=ne%3AtestLayer&bbox=51.230123%2C25.192783%2C51.619153%2C25.405197&width=768&height=419&srs=EPSG%3A404000&format=application/openlayers#toggle&sld=file:///D:/testStyle.sld&styles=testStyle&

What am I doing wrong?

Answer 1

I can achieve the result I am looking for by editing the .sld files located in the data directory of GeoServer directly and not passing any &sld parameters to the request.