code: @Override
  	protected String getElementIdTemplate() {
  		ResourceRef rr = getResourceRef();
  		if(rr != null) {
  			String path = rr.getPath().toString();
  			int slashBefore;
  			if(path.endsWith(Path.SEPARATOR_STRING)) {
  				slashBefore = path.lastIndexOf(Path.SEPARATOR_CHAR, path.length() - 2);
  			} else {
  				slashBefore = path.lastIndexOf(Path.SEPARATOR_CHAR);
  			}
  			String filename = path.substring(slashBefore + 1);
  			if(filename.isEmpty()) throw new IllegalArgumentException("Invalid filename for file: " + path);
  			// Strip extension if will not leave empty
  			int lastDot = filename.lastIndexOf('.');
  			if(lastDot > 0) filename = filename.substring(0, lastDot);
  			return filename;
  		}
  		throw new IllegalStateException("Path not set");
  	}
docs: Does not include the size on the ID template, also strips any file extension if it will not leave the filename empty.