Why does php include statement return whitespace as ajax response

Question

An example of my question in the title demonstrates the problem I'm having.

example

sorry don't know how to use jsfiddle.

And how do I fix it?

Answer 1

It seems your "empty file" contain an empty line, http://wx2fly.com/test/emptyFile.php , which means it's not empty !

I think you can fix your problem by making your empty (or not) file starts with <?php, and be sure the php tag is NOT closed at the end of the file.