IE8 problem with proj4.js

Question

This problem is in IE8 and not in Firefox.

My first problem was that IE8 don't support JSON natively and I get the "JSON is undefined". I solved this by including json2 or json3.

Now JSON.parse (both json2 and json3) throws an exception on proj4.js because of a syntax error.

The projection (from the Danish Geodata Agency) used in leaflet is as follow:

 var crs = new L.Proj.CRS.TMS('EPSG:25832',
                              '+proj=utm +zone=32 +ellps=GRS80 +units=m +no_defs', 
                               [120000, 5900000, 1000000, 6500000], 
                               {resolutions: [1638.4, (...), 0.2, 0.1]
 });

I have removed some of the values from {resolutions}.

Answer 1

proj4.js uses string and array functions (e.g. .split(), .map()) which are not built in to older browsers.

es5-shim (https://github.com/es-shims/es5-shim) fixes this; just load this JavaScript library before anything else (it is benign for newer browsers).

Answer 2

I have realised that proj4js doesn't work in IE below version 9