XML : Remove empty elements from an XML in php

Say I have this XML and I need to remove empty elements (elements that doesn't contain data at all) such as

  ...  <date>      <!-- keep oneDay -->      <oneDay>          <startDate>1450288800000</startDate>          <endDate>1449086400000</endDate>      </oneDay>      <!-- remove range entirely -->      <range>          <startDate/>          <endDate/>      </range>      <!-- remove deadline entirely -->      <deadline>          <date/>      </deadline>  <data>  ...    

The output then should be

  <oneDay> // keep this      <startDate>1450288800000</startDate>      <endDate>1449086400000</endDate>  </oneDay>    

I'm looking for a dynamic solution that would work on any cases like this regardless of the literal name of the element.