Allow to use a proxy to fetch the snippets.

README.md

@@ -124,8 +124,20 @@ an the option `sampler.removeIndentation`.
 }
 ```
 
+### Fetcher URL
+Defining the fetcher URL will prefix all snippet requests with it. 
 
+```js
+{ 
+    sampler : {
+        fetcherURL: 'task.php?file='
+    } 
+}
+```
 
+If you're trying to load a language that your webserver understands (for example PHP) you
+can create a proxy script that passes the source of the file trough. Be careful to 
+limit the script to the source files you would like to deliver.
 
 ### Example
 

sampler.js

@@ -165,13 +165,14 @@
     var config = Reveal.getConfig() || {};
     config.sampler = config.sampler || {};
     var options = {
+        fetcherURL: config.sampler.fetcherURL || '',
         removeIndentation: !!config.sampler.removeIndentation
     };
 
     var elements = document.querySelectorAll('[data-sample]');
     elements.forEach(function(element) {
         var slug = element.getAttribute('data-sample').match(/([^#]+)(?:#(.+))?/);
-        var file = slug[1];
+        var file = options.fetcherURL + slug[1];
         var selector = slug[2];
         var extractor = getSnippetExtractor(selector);