WMSGetFeatureInfo on MapServer WMS layer in OpenLayers 2?

Question

I am trying to get a WMSGetFeatureInfo request to work on my MapServer WMS layer but I am not sure how to correctly configure my map file and the request in OpenLayers.

I have setup a jsFiddle with my WMS overlay and the WMSGetFeatureInfo request.

http://jsfiddle.net/goldrydigital/YBWRz/

The request is as follows:

var getFeatureInfo = new OpenLayers.Control.WMSGetFeatureInfo({
    url: 'http://137.117.37.130:8081/cgi-bin/mapserv.exe?map=c:/ms4w/wms_sample.map&', 
    title: 'Identify features by clicking',
    layers: 'estados'
})
getFeatureInfo.events.register('getfeatureinfo', map, function (e) {
    alert(e.text);
});
map.addControl(getFeatureInfo);
getFeatureInfo.activate();

The layer takes the data from a Mapinfo tab file. The Layer definition in the Map file is as follows:

    LAYER

    NAME "estados"
    TYPE POLYGON
    STATUS ON
    CONNECTIONTYPE OGR
    CONNECTION "estados.tab"
    TEMPLATE "blank.html"
    DUMP TRUE

    CLASS

        OUTLINECOLOR 10 10 10

    END
    METADATA

        "wms_title"          "estados"
        "gml_geometries"     "geom"
        "gml_geom_type"      "polygon"
        "gml_include_items"  "all"
        "wms_include_items"  "all"
        "wms_feature_info_mime_type" "text/plain"

    END

    END

Can you put me in the right direction with this?

Answer 1

In your WMSGetFeatureInfo constructor, the value of the layers property should be an array of layer objects, not the name of the layer.

Answer 2

@drunkenwagoner is correct.

Your call to WMSGetFeatureInfo should look like this

var getFeatureInfo = new OpenLayers.Control.WMSGetFeatureInfo({
    url: 'http://137.117.37.130:8081/cgi-bin/mapserv.exe?map=c:/ms4w/wms_sample.map&', 
    title: 'Identify features by clicking',
    layers: [estadosMexico]
})

The important change being that layers is now associated with [estadosMexico] (rather than "estados" as it was before).

Here's an update of your jsFiddle that does what you were trying to do (shows the alert window when you click on a feature).