[OpenLayers-Users] Geometry.Collection (LineString) GetCentroid - fake?

[Andreas Hocevar]

Hi,

see http://trac.openlayers.org/ticket/2469

Regards,
Andreas.

On 2010-02-17 09:18, BrainDrain wrote:
> Hi.
> I use this function to locate geometry on map
> OpenLayers.Map.prototype.locate = function(geometry, panOnly) {
> 		var bounds = geometry.getBounds();
> 		//this.zoomToExtent(bounds);
> 		//this.zoomToScale(scale);
> 		if ((this.getExtent().containsBounds(bounds) ||
> this.getZoomForExtent(bounds) > this.zoom) || panOnly) {
> 			//wrong for complex LineStrings (points to the center of the extent - not
> center of the geometry)
>                         //this.panTo(bounds.getCenterLonLat());
>  
>                         //incorrect with current implemetation of
> Geometry.Collection GetCentroid 
> 			//this.panTo(WEM.Util.point2ll(geometry.getCentroid()));
> 									
> 			var parser = new OpenLayers.Format.WKT();
>                         //this works - BUT! I need to send all geometry WKT
> to the server
>                         //server (MapServer mapscript c# via webservice
> webmetod) getCentroid works perfectly
> 			application.server.MapParser.GetCentroid(parser.write(geometry),
> function(geometryWKT, scope) {
> 				scope.panTo(WEM.Util.point2ll(parser.read(geometryWKT).geometry));
> 			}, null, this);			
> 		}
> 		else {
> 			var zoom = this.zoom;
> 			this.zoomToExtent(bounds);
> 			this.zoomTo(zoom);
> 		}
> };
>
> What's this (for ex. for LineString)???
> /**
>      * APIMethod: getCentroid
>      *
>      * Returns:
>      * {<OpenLayers.Geometry.Point>} The centroid of the collection
>      */
>     getCentroid: function() {
>         return this.components.length && this.components[0].getCentroid();
> //just great)))(((!
>     }
>
> Currently I can:
>  - pass only featureId to the server (not all geometry text)
>  - get centroid forcibly on server on querying features and then use it
>  - compress geometry WKT with JavaScript lib (deflate) and decompress on
> server as I do it on update feature....
> But I want correct getCentroid implemetation
>   


-- 
Andreas Hocevar
OpenGeo - http://opengeo.org/
Expert service straight from the developers.