[OpenLayers-Users] Destroy/Delete a vector feature

[Eric Lemoine]

On Tue, Dec 16, 2008 at 7:09 PM, Yves Moisan <yves.moisan at boreal-is.com> wrote:
>
>> My first thought is that after the data is loaded, if I could get the
>> feature by ID or attribute and then destroy it, that would be great.
>
> If you get to doing something like that, please share your code :-).
> I'm trying to do something similar, that is set the state property of
> the features in my GeoJSON response along the lines of :
>
> pts_gps = new OpenLayers.Layer.Vector("GeoJSON", {
>                                   // styleMap: styleMap,
>                    strategies: [new OpenLayers.Strategy.BBOX()],
>                    protocol: new OpenLayers.Protocol.HTTP({
>                        url: "http://myserver/PGTEST4326/all.json",
>                        format: new OpenLayers.Format.GeoJSON()
>                    }),
>                                        eventListeners: {
>                    loadend: function(??) {
>                                        for (var i = 0, var len = pts_gps.features.length; i < len; i++) {
>                pts_gps.features[i].state = OpenLayers.State.UNKNOWN;
>                }} }
>
>                });
>
> and it doesn't work ...

I think you should use the Style framework for this.

Try this:

var tpl = {"display": "${getDisplay}"};
var ctx = {
    "getDisplay": function(feature) {
        // "fid" is the identifier of the feature
        // to filter out
        return feature.fid == "fid" ? "none" : "";
    }
};
var style = new OpenLayers.Style(tpl, {
    "context": ctx}
);
var layer = new OpenLayers.Layer.Vector("vec", {
    styleMap: style
});

(hmm, this may not work because of a limitation in the Style implementation!)

I see this as an alternative:

var style = new OpenLayers.Style();
var rule = new OpenLayers.Rule({
    "symbolizer": {"display": "none"},
    "filter": new OpenLayers.Filter.FeatureId({
        "fids": ["fid"]
    })
});
var elseRule = new OpenLayers.Rule({
    elseFilter: true
});
style.addRules([rule, elseRule]);
var layer = new OpenLayers.Layer.Vector("vec", {
    styleMap: style
});


This is untested.

Cheers,

--
Eric