Is it possible to configure WFS layer to use GET requests?

Question

Accordingly specification manipulation with WFS services can be perform using POST or GET (for example, http://demo.opengeo.org/geoserver/wfs?service=wfs&version=1.1.0&request=GetFeature&typeName=topp:states) requests. Is it possible to configure OpenLayers for using only GET requests (by default POST is used). Now my code looks like:

wfs = new OpenLayers.Layer.Vector('Example of WFS layer', {
    strategies: [new OpenLayers.Strategy.BBOX()],
    visibility: true,
    protocol: new OpenLayers.Protocol.WFS(wfs_property)
});

Answer 1

I've solved my problem. For using GET request should use OpenLayers.Protocol.HTTP instead OpenLayers.Protocol.WFS.

wfs_options = {
    url: 'http://fakeurl/tinyows.cgi?',
    params: {
        request: "GetFeature",
        service: "wfs",
        version: "1.0.0",
        typeName: "layername"
    },
    format: new OpenLayers.Format.GML({
        featureNS: "http://ng.org/sf",
        geometryName: "wkb_geometry"
    })
}

wfs = new OpenLayers.Layer.Vector('WFS', {
    strategies: [new OpenLayers.Strategy.Fixed()],
    visibility: true,
    protocol: new OpenLayers.Protocol.HTTP(wfs_options),
});

Answer 2

A look at the source code seems to show the POST is hard coded in in WFS protocol.

/* part from source with own comments v2.11: lib/OpenLayers/Protocol/WFS/v1.js */
read: function(options) {
    OpenLayers.Protocol.prototype.read.apply(this, arguments);
    options = OpenLayers.Util.extend({}, options);
    OpenLayers.Util.applyDefaults(options, this.options || {});
    var response = new OpenLayers.Protocol.Response({requestType: "read"});

    /* this here seems to be changed - imo it constructs the post xml data */
    var data = OpenLayers.Format.XML.prototype.write.apply(
        this.format, [this.format.writeNode("wfs:GetFeature", options)]
    );

    /* hard coded? */
    response.priv = OpenLayers.Request.POST({
        url: options.url,
        callback: this.createCallback(this.handleRead, response, options),
        params: options.params,
        headers: options.headers,
        data: data
    });

    return response;
},

So my idea try to override the read function with your own WFS protocol implementation. The samples 'lib/OpenLayers/Protocol/WFS/v1_*_0.js' can be a good starting point. You should call it with something like that. wfs = new OpenLayers.Layer.Vector('Example of WFS layer', { strategies: [new OpenLayers.Strategy.BBOX()], visibility: true, protocol: new OpenLayers.Protocol.WFS.v1_withGet(wfs_property) });

But it seems to be the hard way :-D