在Mapnik中定义XML标注线状要素

 <Map background-color="#efefef" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
    <Style name="My Style">
        <Rule>
            <LineSymbolizer stroke="rgb(85%,85%,85%)" stroke-width="20" stroke-linecap="round"/>
            <Filter>[id] = 1</Filter>
            <TextSymbolizer face-name="DejaVu Sans Book" size="10" placement="point" allow-overlap="true">[name]
            </TextSymbolizer>
        </Rule>
        <Rule>
            <LineSymbolizer stroke="rgb(85%,85%,85%)" stroke-width="20" stroke-linecap="round"/>
            <Filter>[id] = 2</Filter>
            <TextSymbolizer face-name="DejaVu Sans Book" size="10" placement="line" allow-overlap="true"
                            spacing="8">[name]
            </TextSymbolizer>
        </Rule>

        <Rule>
            <LineSymbolizer stroke="rgb(85%,85%,85%)" stroke-width="20" stroke-linecap="round"/>
            <Filter>[id] = 3</Filter>
            <TextSymbolizer face-name="DejaVu Sans Book" size="10" placement="line" allow-overlap="true"
                            spacing="8" max-char-angle-delta="0">
                [name]
            </TextSymbolizer>
        </Rule>
    </Style>
    <Layer name="world" srs="+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs">
        <StyleName>My Style</StyleName>
        <Datasource>
            <Parameter name="type">shape</Parameter>
            <Parameter name="file">../fig_data/xx_fig_data_line.shp</Parameter>
        </Datasource>
    </Layer>
</Map>