Addition of ol.format.OGC

[gevrum]

There is an example in documentation, which generates XML for GetFeature request.
http://openlayers.org/en/v3.20.1/apidoc/ol.format.filter.html

Is there any plans to make writer for WMS parameter from OL filter?

It could be made earlier in OL2 like this:

if (layer instanceof OpenLayers.Layer.Vector) {
            layer.filter = filter;
            layer.refresh({ force: true });
        } else if (layer instanceof OpenLayers.Layer.WMS) {
            var parser = new OpenLayers.Format.Filter.v1_1_0();    
            var filterAsXml = parser.write( filter );    
            var xml = new OpenLayers.Format.XML();
            var filterAsStringOGC = xml.write( filterAsXml );
            layer.mergeNewParams({ filter: filterAsStringOGC });
            layer.redraw();
        }

[bartvde]

See: #5691