[OpenLayers-Users] need a clarification re styleMaps

[Puneet Kishor]

The following code works

    // Add styleMap to layer
    var style_map = new OpenLayers.StyleMap({
        externalGraphic: uri + "/img/arrow.png",
        graphicWidth: 15,
        graphicHeight: res[0].height,
        rotation: res[0].angle
    });
    var lyr = new OpenLayers.Layer.Vector("name", {styleMap: style_map});
    
    // Points without styleMap
    var points = [];
    points.push(
        new OpenLayers.Feature.Vector(
            new OpenLayers.Geometry.Point(res[0].lng, res[0].lat)
        )
    );
    lyr.addFeatures(points);
    map.addLayer(lyr);

everything works. Different points get drawn with symbols of correct height and rotation. But, if I don't add the styleMap definition to the lyr when creating it, and instead, add it to the point, like so

    // Layer with styleMap
    var lyr = new OpenLayers.Layer.Vector("name");
    
    // Add styleMap to each point
    var style_map = new OpenLayers.StyleMap({
        externalGraphic: uri + "/img/arrow.png",
        graphicWidth: 15,
        graphicHeight: res[0].height,
        rotation: res[0].angle
    });
    
    var points = [];
    points.push(
        new OpenLayers.Feature.Vector(
            new OpenLayers.Geometry.Point(res[0].lng, res[0].lat), 
            {styleMap: style_map}
        )
    );
    lyr.addFeatures(points);
    map.addLayer(lyr);
    
then nothing gets drawn. At best, this is counter-intuitive to me… the style is per point, not per layer. At worst, this creates a problem for me that I don't know how to solve. I am creating a layer that I want to reuse. If I follow the first approach above, the first time around everything works well. But, on subsequent iterations the points get drawn with the previously set style (rotation and height).

Suggestions?

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Puneet Kishor