Create a dropdown menu output (server side; deprecated)

This is the server-side function for creating a dynamic dropdown menu.

renderDropdownMenu(expr, env = parent.frame(), quoted = FALSE)

Arguments

expr	An expression that returns a Shiny tag object, HTML, or a list of such objects.
env	The environment in which to evaluate expr.
quoted	Is expr a quoted expression (with quote())? This is useful if you want to save an expression in a variable.