[TYPO3-english] tt_news problem; how to test if a list news is empty

[Patrik]

News have more than one category. If news does not include category, display
all news.

TS:
plugin.tt_news {
  #one of category
  categorySelection = 44
  # show only selected categories
  categoryMode = 1
}

if  -> news empty                ??
plugin.tt_news  {
  # show all
  categoryMode = 3
}