Added support for a optional path modifier callback

Readme.md

@@ -28,6 +28,11 @@ fileinclude('@@')
   - filters: `object`, filters of include content
   - context: `object`, context of `if` statement
   - indent: `boolean`, default `false`
+  - getPath: `function`, default: `null`, a optional callback to modify the include path
+
+          function (path) {
+              return path.replace('__LANG__', 'de');
+          }
 
 * options.basepath - type: `string`, it could be
   - `@root`, include file relative to the dir where `gulp` running in

lib/index.js

@@ -22,7 +22,8 @@ module.exports = function(opts) {
     suffix: '',
     context: {},
     filters: false,
-    indent: false
+    indent: false,
+    getPath: null
   }, opts);
 
   if (opts.basepath !== '@file') {
@@ -118,6 +119,12 @@ module.exports = function(opts) {
 
       if (args) {
         var includePath = path.resolve(filebase, args[1]);
+
+        // check for path modifier callback
+        if (typeof opts.getPath === 'function') {
+            includePath = opts.getPath(includePath)
+        }
+
         // for checking if we are not including the current file again
         if (currentFilename.toLowerCase() === includePath.toLowerCase()) {
           throw new Error('recursion detected in file: ' + currentFilename);
@@ -176,6 +183,12 @@ module.exports = function(opts) {
 
         if (arr) {
           var includePath = path.resolve(filebase, args[1]);
+
+          // check for path modifier callback
+          if (typeof opts.getPath === 'function') {
+            includePath = opts.getPath(includePath)
+          }
+
           // for checking if we are not including the current file again
           if (currentFilename.toLowerCase() === includePath.toLowerCase()) {
             throw new Error('recursion detected in file: ' + currentFilename);