[nj] added renderCaller filter as workaround of mozilla/nunjucks#783

CHANGELOG.md

@@ -8,6 +8,7 @@
 ### Added
 - [nj] Added `example()` macro which allows to quickly output demo of any html or css
 - [nj] Added early version of Examples page, which showcasing large portion (but not all) of Ekzo helpers and objects
+- [nj] Added `renderCaller` filter as workaround of that issue https://github.com/mozilla/nunjucks/issues/783
 
 ### Fixed
 - Fixed typo in Grunt's watch config

source/layouts/components/_example.nj

@@ -27,7 +27,7 @@
     </div>
 
     <div class='o-grid__item h-1/1 h-margin-top {{ 'h-2/9@tablet h-margin-top0@tablet' if not full }}'>
-      {{ caller() }}
+      {{ caller()|renderCaller }}
     </div>
 
     <div class='o-grid__item h-1/1 h-margin-top {{ 'h-5/9@tablet h-margin-top0@tablet' if not full }}'>

tasks/grunt-nunjucks-2-html.coffee

@@ -57,6 +57,7 @@ module.exports = (grunt) ->
   i18n         = new Gettext()
   marked       = require('marked')
   markdown     = require('nunjucks-markdown')
+  nunjucks     = require('nunjucks')
   urlify       = require('urlify').create({
     addEToUmlauts : taskConfig.urlify.addEToUmlauts
     szToSs        : taskConfig.urlify.szToSs
@@ -400,6 +401,18 @@ module.exports = (grunt) ->
             array.push(value)
             array
 
+          ###*
+           * Renders output of `caller()` once again. Useful if you're
+           * using `{% raw %}` block inside of call, for example,
+           * to showcase nunjucks code
+           * @param {object} caller Caller to force render
+           * @return {string} Rendered html
+           *
+           * @todo  Related to this issue https://github.com/mozilla/nunjucks/issues/783
+          ###
+          env.addFilter 'renderCaller', (caller) ->
+            nunjucks.renderString(caller.val, this.getVariables());
+
           ###*
            * Get language code from locale, without country
            * @param {string} locale = currentLocale Locale, from which should be taken language code