Thank you very much for your answer. I have therefore started to investigate the possiblity to use the GeoJSON format, and now I am trying to train with this format with this example but it doesn't work
<script type="text/javascript"> var map = new OpenLayers.Map("my_map"); var layer = new OpenLayers.Layer.OSM("OpenStreetMap"); map.addLayer(layer); map.addControl(new OpenLayers.Control.LayerSwitcher()); map.setCenter(new OpenLayers.LonLat(0,0), 2); var citiesLayer = new OpenLayers.Layer.Vector("World Cities (GeoJSON)", { protocol: new OpenLayers.Protocol.HTTP({ url: "http://localhost/openlayers/world_cities.json", format: new OpenLayers.Format.GeoJSON() }), strategies: [ new OpenLayers.Strategy.Fixed(), new OpenLayers.Strategy.Cluster({distance: 15}) ] }); map.addLayer(citiesLayer); </script> In order to make the protocol work I have installed nginx on my laptop and the url correctly points to the file world_cities.json in my browser. Anyway this example doesn't work, any idea why? Thanks! Niccolò 2014-09-19 15:54 GMT+02:00 Mark Prins <mc.pr...@gmail.com>: > using plain text or (geo) json is much less error prone than using > GML, and probably gives better performance > > 2014-09-19 15:45 GMT+02:00 Niccolò Dal Santo <ncl.dalsa...@gmail.com>: > > Hi there, > > > > I am new of Openlayers and I need to show some points that come from a > > database on a map centred in Turin (Italy), with some information > related to > > this point (for instance an image). Searching on line I have found that > > Openlayers supports many formats of data like GML, KML, GeoJSON and many > > others. Could you suggest a format useful fror my problem and maybe some > > examples of how to use it? > > > > I have tried with this code generating a map of europe, but it doesn't > work > > > > <html> > > <head> > > <title>Prova GML</title> > > <script src="http://openlayers.org/api/OpenLayers.js"></script> > > </head> > > <body> > > <div id="ch3_gml" style="width: 100%; height: 100%;"></div> > > > > <script type="text/javascript"> > > > > // Create the map using the specified DOM element > > var map = new OpenLayers.Map("ch3_gml"); > > > > var layer = new OpenLayers.Layer.OSM("OpenStreetMap"); > > map.addLayer(layer); > > > > map.addControl(new OpenLayers.Control.LayerSwitcher()); > > map.setCenter(new OpenLayers.LonLat(0,0), 2); > > > > map.addLayer(new OpenLayers.Layer.Vector("Europe (GML)", { > > protocol: new OpenLayers.Protocol.HTTP({ > > url: "./europe.gml", > > format: new OpenLayers.Format.GML() > > }), > > strategies: [new OpenLayers.Strategy.Fixed()] > > })); > > </script> > > </body> > > </html> > > > > where europe.gml is a gml file in the same folder of this script, but > > nothing happens. > > > > Thank you very much for your help! > > > > Regards > > > > Niccolò > > > > -- > > Niccolò Dal Santo > > +39 342 15 70 842 > > ncl.dalsa...@gmail.com > > > > _______________________________________________ > > Users mailing list > > us...@lists.osgeo.org > > http://lists.osgeo.org/mailman/listinfo/openlayers-users > > > > -- > Disclaimer; > This message is just a reflection of what I thought at the time of > sending. The message may contain information that is not intended for > you or that you don't understand. > _______________________________________________ > Users mailing list > us...@lists.osgeo.org > http://lists.osgeo.org/mailman/listinfo/openlayers-users -- Niccolò Dal Santo +39 342 15 70 842 ncl.dalsa...@gmail.com
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