[OpenLayers-Users] WMS GetFeatureInfo - difficult to click
exactly on a point
Richard Greenwood
richard.greenwood at gmail.com
Thu Jan 29 21:20:38 EST 2009
> 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
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