How do I use the FEATURETYPE for GetLegendGraphic request?

Question

I'm using the following SLD for Rendering a Polygon using GeoServer:

<?xml version="1.0" encoding="ISO-8859-1"?>
<StyledLayerDescriptor version="1.0.0"
                       xsi:schemaLocation="http://www.opengis.net/sld http://schemas.opengis.net/sld/1.0.0/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>City</Name>
    <UserStyle>
      <Title>City</Title>

      <FeatureTypeStyle>
        <Rule>

          <PolygonSymbolizer>
            <Stroke>
              <CssParameter name="stroke">#FFFFFF</CssParameter>
              <CssParameter name="stroke-width">3</CssParameter>
            </Stroke>
          </PolygonSymbolizer>
        </Rule>
      </FeatureTypeStyle>

      <FeatureTypeStyle>
        <Rule>
          <Title>City</Title>
          <PolygonSymbolizer>
            <Stroke>
              <CssParameter name="stroke">#000000</CssParameter>
              <CssParameter name="stroke-width">1</CssParameter>
            </Stroke>
          </PolygonSymbolizer>
        </Rule>
      </FeatureTypeStyle>

    </UserStyle>
  </NamedLayer>
</StyledLayerDescriptor>

When I make a GetLegendGraphic request, I get an image like:

As you can see, it is showing both the FeatureStyles, because of which the top part of the Legend Graphic looks empty.

I know that there is a FEATURETYPE Parameter on the GetLegendGraphic request, but I can find an example of what I need to specify here.

How do I use the FEATURETYPE for GetLegendGraphic request?

Answer 1

As @user30184 says the FeatureType parameter is for situations where you have multiple types of feature in a layer and only want the legend for one of them. In your case you have multiple rules and only want one of them to be shown. For this you want the Rule parameter:

http://.......&RULE=City 

When the label of the Rule disappears, and you want to get it back, you can do so by using forceLabels:on as part of the legend_options in the request URL.