Restricting User on ability to chose maximum items from selectInput

Question

Shiny function selectInput() gives an option to select multiple items from the dropdown list with 'multiple = TRUE'

However I want to restrict user on how many items max can be chosen from underlying dropdown list.

Can you please suggest if that is possible with Shiny.

Appreciate for any pointer.

Thanks,

Answer 1

You can do this if you define it as selectizeInput() instead of selectInput(), and use the options = list(maxItems = n) parameter.

For example

selectizeInput("select", "Select", LETTERS, options = list(maxItems = 4))