[OpenLayers-Users] remove a layer by name

[Mr. Puneet Kishor]

I would like to remove a layer by name. The only method I see for removing layer seems to take a layer object, which implies something like so

    var lyr_list = map.getLayersByName(name);

Why does the above return a list? Under what use case would one have more than one layer by the same name? In any case, I have all layers with unique names, so the list would always have only one element.

    map.removeLayer(lyr_list[0]);

The above works, but is there a more efficient or better way?

A related question -- I am drawing 3 or 4 vector (line and point) layers first, and then another vector layer with about 3000 points. Then, I want to redraw this last layer, again with 3000 points, same data, different filter. Since the user might want to bring back the first version of it, would it be advisable to not remove the layer but to just turn its visibility off, and draw a completely different layer? Would there be a performance hit?

Finally, to build on the above -- I am trying to balance between drawing images really fast on the server (WMS), but having limited interactivity in the browser, vs. drawing vector layers in the browser, providing interactivity, but potentially hurting performance. Right now I am not sure of the bottlenecks (is there a way to profile the code?). The layers seem to take a while coming, and then they draw instantly. Don't know if OL waits to display the layer until after all the features have been rendered. For now, I have approx 4-6 MB of data coming down the pipe for approximately half a dozen layers. Just trying to gauge the limits without indulging in too much premature optimization.

Thanks,

Puneet.