[TYPO3-ttnews] tt_news: Condition based on category in single view

[Florian Seirer]

I'd like to set some TYPOScript values based on the category the tt_news record has.
Basically, if  the record has the category 123, then set 

plugin.tt_news.firstImageIsPreview = 1
plugin.tt_news.forceFirstImageIsPreview = 1 

in the SINGLE view.

Any ideas how to achieve this? Google doesn't have an answer, and neither have I...