Make a value reactive if it is not already reactive.

This is used to allow parameters to Shiny functions to be optionally reactive.

ensure_reactive(
  item,
  name = NULL,
  env = NULL,
  default = function() stop("Missing ", name)
)

Arguments

item: Thing to ensure reactive, either an already reactive value, or a plain value, or NULL.
name: If item is NULL, env[[name]]() will be used.
env: If item is NULL, env[[name]]() will be used.
default: If item is NULL, and name is not in env, this reactive value will be used.

A Shiny reactive value.