R DT filter disabled and greyed

Question

In R Shiny applications, at what situations will the filter boxes get greyed.

Like, is there a limit on the number of filters can be applied to a datatable?

I searched https://rstudio.github.io/DT/ but didn't find anything relevant.

Answer 1

灰色空格表示列中只有一个唯一值（不超过要筛选的列中的一个选项）