> I'm writing an OGC/WMS Viewer using jQuery. One task I need > to accomplish involves making a getCapabilities request > against a Web Mapping Service, which responds with some XML. > > I know that the $.ajax function allows me to get JSON from > another domain, but is there a way to get XML from another > domain? I've tried various permutations of data types, and > the $.ajax call with the "jsonp" call gets closest--it > returns the XML, but since it's not true JSON, the browser complains. > > Is my only option to use a proxy web service to access the XML?
Yes, that is your only option, unless the web mapping service has the option to return JSONP (or any kind of executable JavaScript code) instead of XML. XMLHttpRequest is limited to the same-domain rule. Script tags/elements are not. You can load a script tag or element from any URL. Cross-domain JSONP is simply a way to wrap up JSON data inside a piece of executable JavaScript code, so that it can be loaded in a script tag/element instead of through XMLHttpRequest. Do you need some code for a simple PHP proxy? It's only a few lines of code. Give me a shout if you need it and I'll post the one I use - otherwise just search for "php proxy" and you'll find some. Or you can find similar code for any server language. Just watch out that you don't run an open proxy inadvertently! Burn the address of the web mapping service into the proxy server's requests, so people can't use it for nefarious purposes. -Mike
