Allow fields to be wrapped in XML CDATA

Patch with implementation.

thanks Dmitriy.trt for the patch, exactly what i needed.
I made small change so the CDATA is not applied on empty content.

Sorry for not using git patch, but the code below is pretty self explainable.

Index: views_data_export.theme.inc
===================================================================
--- views_data_export.theme.inc	(revision 681)
+++ views_data_export.theme.inc	(working copy)
@@ -383,7 +383,7 @@
           array('<', '>'),
           $content);
       }
-      else{
+      elseif(!empty($content)) {
         // Escape CDATA end sequence only.
         $content = '<![CDATA[' . str_replace(']]>', ']]]]><![CDATA[>', $content) . ']]>';
       }

Patch looks RTBC to me, integrated the suggestions from #2.

Zero will not be wrapped with CDATA. It's just a guess. Please set back to RTBC if I'm wrong.

Right, we should better check for the empty string instead of using empty().

Integer zero can't get here, right? Asking because 0 != '' results in FALSE and integer zero still won't be wrapped. Sorry I don't have this module installed at the moment and can't dig into it with debugger or properly analyze the code.

Hi, it would be great if it were possible to apply CDATA to individual fields rather than all fields in the view.

Ok so I need it to be based on per field. So I am attaching a patch for review.Also a cleanup as there were some + signs in the comments.

Setting it to needs review.

This patch looks okay, but we need some tests to make sure this functionality works. There should be test for not-escaping certain fields, which would be a good basis for a test.

Here's a patch for the testbot.

Thanks everyone, committed to 7.x-3.x.

Now needs backporting.

removed comments that were potentially unrelated to the feature request/issue

@junedkazi thanks for the patch!