Alternate colors of GeoJSON linestring segments in OpenLayers?

Question

I am rendering a vector linestring via GeoJSON on top of an OpenLayers map. I'd like to alternate the styling between two slightly different shades of blue, such that the colors alternate from one line segment to the next. Is there any way to do this, apart from using points instead of a linestring and constructing the line segments myself?

var path;

function drawPath(table, x, y, id) {
  var urlreq = "../grab.php?method=get_path&x=" + x + "&y=" + y + "&table=" + table +
                "&id=" + id;
  if( typeof(path) != 'undefined' ) { map.removeLayer(path); }
  path = new OpenLayers.Layer.Vector("Path", {
    projection: epsg900913,
    style: {
      strokeColor: "blue",
      strokeWidth: 3
    },
    strategies: [new OpenLayers.Strategy.Fixed()],
    protocol: new OpenLayers.Protocol.HTTP({
      url: urlreq,
      format: new OpenLayers.Format.GeoJSON()
    })
  });
  map.addLayer(path);
}

Answer 1

You can use PointTrack layer. See my live example here.

I think code below helps you to understand how to build layer over requested data:

features = [];
json = new OpenLayers.Format.GeoJSON();

OpenLayers.Request.GET({
    url: "../grab.php?method=get_path&x=" + x + "&y=" + y + "&table=" + table + "&id=" + id",
    async: false,
    success: function(r){
        features = json.read(r.responseText);
    }
});

track_layer = new OpenLayers.Layer.PointTrack('Track');
map.addLayer(track_layer);
track_layer.addNodes(features);