PolygonSymbolizer

A PolygonSymbolizer styles features as polygons. Polygons are two-dimensional geometries. They can be depicted with styling for their interior (fill) and their border (stroke). Polygons may contain one or more holes, which are stroked but not filled. When rendering a polygon, the fill is rendered before the border is stroked.

Syntax

A <PolygonSymbolizer> contains an optional <Geometry> element, and two elements <Fill> and <Stroke> for specifying styling:

Tag

Required?

Description

<Geometry>

No

Specifies the geometry to be rendered.

<Fill>

No

Specifies the styling for the polygon interior.

<Stroke>

No

Specifies the styling for the polygon border.

Geometry

The <Geometry> element is optional. If present, it specifies the featuretype property from which to obtain the geometry to style using the PropertyName element. See also Geometry transformations in SLD for GeoServer extensions for specifying geometry.

Any kind of geometry may be styled with a <PolygonSymbolizer>. Point geometries are treated as small orthonormal square polygons. Linear geometries are closed by joining their ends.

Stroke

The <Stroke> element specifies the styling for the border of a polygon. The syntax is described in the <LineSymbolizer> Stroke section.

Fill

The <Fill> element specifies the styling for the interior of a polygon. It can contain the sub-elements:

Tag

Required?

Description

<GraphicFill>

No

Renders the fill of the polygon with a repeated pattern.

<CssParameter>

0..N

Specifies parameters for filling with a solid color.

GraphicFill

The <GraphicFill> element contains a <Graphic> element, which specifies a graphic image or symbol to use for a repeated fill pattern. The syntax is described in the PointSymbolizer Graphic section.

CssParameter

The <CssParameter> elements describe the styling of a solid polygon fill. Any number of <CssParameter> elements can be specified.

The name attribute indicates what aspect of styling an element specifies, using the standard CSS/SVG styling model. The content of the element supplies the value of the styling parameter. The value may contain expressions.

The following parameters are supported:

Parameter

Required?

Description

name="fill"

No

Specifies the fill color, in the form #RRGGBB. Default is grey (#808080).

name="fill-opacity"

No

Specifies the opacity (transparency) of the fill. The value is a decimal number between 0 (completely transparent) and 1 (completely opaque). Default is 1.

Example

The following symbolizer is taken from the Polygons section in the SLD Cookbook.

1        <PolygonSymbolizer>
2          <Fill>
3            <CssParameter name="fill">#000080</CssParameter>
4          </Fill>
5        </PolygonSymbolizer>

This symbolizer contains only a <Fill> element. Inside this element is a <CssParameter> that specifies the fill color for the polygon to be #000080 (a muted blue).

Further examples can be found in the Polygons section of the SLD Cookbook.

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