[OpenLayers-Users] How to make symbolizers use attribute values in OpenLayers.Layer.WMS?

[joaorodr84]

I know it works like a charm for vector layers. But considering that we can
make the symbolizers use attribute values in the SLD, I think OpenLayers
should support it. But apparently it doesn't.

In the example below, I have a layer with 10 points, where the attribute
*ogc_fid* has the values 1, 2, ..., 10.

I want the stroke width of each point to be the value of its *ogc_fid*
attribute.  Here <http://codepen.io/joaorodr84/pen/LVRQgg>   is the whole
code, but I will explain the most important parts.

    /* Rule */
    var rule = new OpenLayers.Rule({
        filter: filter,
        symbolizer: {
            Point: {
                fillColor: '#dddd00',
                fillOpacity: 1,
                pointRadius: 30,
                strokeWidth: '${ogc_fid}',
                graphicName: 'circle'
            },
            Text: {
                label: '${ogc_fid}'
            }
        }
    });

Above, I have the rule, where I use *strokeWidth: '${ogc_fid}'* indicating
that I want the stroke width to assume the value of the `ogc_fid` attribute
of its respective point.

I convert it to SLD using the *OpenLayers.Format.SLD().write* method, and I
get this:

    <sld:CssParameter name="stroke-width">${ogc_fid}</sld:CssParameter>

When I should be getting this:

    <sld:CssParameter name="stroke-width">
        <ogc:PropertyName>ogc_fid</ogc:PropertyName>
    </sld:CssParameter>

The button *Custom SLD depending on stroke width (hard coded)* set a custom
SLD that I hard coded and that contains the above correction. This way, you
can see what I am looking for.

My big questions are:
1) Why doesn't the *OpenLayers.Format.SLD().write* method do this correction
automatically?
2) How could I obtain a correct conversion to SLD? Maybe by overloading the
`OpenLayers.Format.SLD().write` method. But how??

Thanks a lot!

João Rodrigues



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