[OpenLayers-Users] WMS GetFeatureInfo - difficult to click exactly on a point

[Richard Greenwood]

> Kimball, David (DCR) wrote:
>> Hi everyone,
>>
>> I'm using a WMS GetFeatureInfo to simultaneously query the attributes of
>> a line layer and a point layer (from GeoServer).  Unfortunately you have
>> to click *exactly* on the center of a point to get it to send you the
>> point attributes.
>>
>> http://maps.massgis.state.ma.us/dcr/trails/DCR_RoadTrail10.html
>>
>>
>>       map.events.register('click', map, function (e) {
>>               var url =  map.layers[0].getFullRequestString(
>>               {
>>                       REQUEST: "GetFeatureInfo",
>>                       EXCEPTIONS: "application/vnd.ogc.se_xml",
>>                       BBOX: map.getExtent().toBBOX(),
>>                       X: e.xy.x,
>>                       Y: e.xy.y,
>>                       INFO_FORMAT: 'text/html',
>>                       QUERY_LAYERS: map.layers[8].params.LAYERS + ","
>> + map.layers[9].params.LAYERS,
>>                       FEATURE_COUNT: 50,
>>                       WIDTH: map.size.w,
>>                       HEIGHT: map.size.h
>>               },
>>
>> "http://giswebservices.massgis.state.ma.us/geoserver/wms");
>>               OpenLayers.loadURL(url, '', this, setHTML, setHTML);
>>               OpenLayers.Event.stop(e);
>>
>>
>> I searched a bunch for this and all I could find were suggestions to do
>> a WFS getfeature instead of a WMS GetFeatureInfo, or to set some options
>> on the server (not an option in this case).  I'd rather use the WMS
>> request because I'd rather not rewrite all my parsing Javascript, and
>> there might be a performance hit - some of the lines have hundreds of
>> vertices, and when I tried a similar approach recently with large
>> polygons it was slow because of the large amount of data sent back.
>>
>> So, is there any (client-side) radius/tolerance option for
>> GetFeatureInfo?
>>
>> Thanks a lot,
>>
>> David

Look at TOLERANCE in http://www.mapserver.org/mapfile/layer.html

-- 
Richard Greenwood
richard.greenwood at gmail.com
www.greenwoodmap.com