Red line strategy

I need to overlay a red line through a field, depending on certain conditions.

In FMP my practice was to create a container calc that returned a container field if the condition was met, otherwise set empty.

I assume this can also be done in Servoy. But does JavaScript offer a better means to accomplish the same?

Well, my FMP-style strategy works. I still have a lingering feeling there’s a more elegant way of doing this in Servoy.