GeoHack/Replacement script

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/* Replace external links to GeoHack with direct links to a single mapping provider.
 *
 * It support the following replacement variables found in GeoHack:
 * {latdegdec} {londegdec} {scale} {span} {osmzoom}
 *
 * Maintainer: [[User:Dispenser]]
 * Released into the Public Domain
 */
function replaceGeoHack(){
	var mapprovider = "http://maps.google.com/maps?ll={latdegdec},{londegdec}&spn={span},{span}&q={latdegdec},{londegdec}";
	//var mapprovider = "http://www.openstreetmap.org/index.html?mlat={latdegdec}&mlon={londegdec}&zoom={osmzoom}&layers=B000FTF";
	var geohack_base = "http://toolserver.org/~geohack/geohack.php";
	var coord_filter = /&params=([\d.+-]+)_([\d.+-]*)_?([\d.+-]*)_?([NSZ])_([\d.+-]+)_([\d.+-]*)_?([\d.+-]*)_?([EOW])([^&=]*)/;
	var link, lat, lon, scale;
	var links = document.getElementsByTagName('A');
	for(var i=0; (link=links[i]); i++){
		if(link.href.indexOf(geohack_base)==0 && coord_filter.exec(link.href)) {
			// latitude and longitude
			lat=(1.0*RegExp.$1) + ((RegExp.$2||0)/60.0) + ((RegExp.$3||0)/3600.0);
			if(RegExp.$4!='N') lat*=-1;
			lon=(1.0*RegExp.$5) + ((RegExp.$6||0)/60.0) + ((RegExp.$7||0)/3600.0);
			if(RegExp.$8=='W') lon*=-1;
			
			// Determine scale/zoom
			var params = RegExp.$9;
			if(/_globe:(?!earth|_|$)/i.test(params)) continue;
			if(/_type:(adm3rd|city|mountain|isle|river|waterbody)/.test(params))scale = 100000;
			else if(/_type:(event|forest|glacier)/.test(params))scale = 50000;
			else if(/_type:(airport|edu|pass|landmark|railwaystation)/.test(params))scale = 10000;
			else scale = 300000;
			if(/_dim:([\d.+-]+)(km)?m?/.exec(params))scale = RegExp.$1 * (RegExp.$2?10000:10);
			if(/_scale:(\d+)(_|$)/.exec(params))scale = RegExp.$1;
			var osmzoom = 18 - Math.round(Math.log(scale/1693) / Math.log(2));
			var zoom =  Math.log( 1.5e8/scale) / Math.log(2);
			
			// Replace link
			link.href=mapprovider.replace(/\{latdegdec\}/g, lat).replace(/\{londegdec\}/g, lon).replace(/\{scale\}/g, scale)
			                     .replace(/\{span\}/g, scale/1e6).replace(/\{osmzoom\}/g, osmzoom).replace(/\{zoom\}/g, zoom);
		}
	}
}

if(doneOnloadHook) replaceGeoHack(); //imported dynamically
else addOnloadHook(replaceGeoHack);

Category:Geo tools