Wraps a normal function to create a reactive function.
Conceptually, a reactive function is a function whose
result will change over time.
Usage
reactive(x)
Arguments
x
The value or function to make reactive. The
function must not have any parameters.
Value
A reactive function. (Note that reactive functions can
only be called from within other reactive functions.)
Details
Reactive functions are functions that can read reactive
values and call other reactive functions. Whenever a
reactive value changes, any reactive functions that
depended on it are marked as "invalidated" and will
automatically re-execute if necessary. If a reactive
function is marked as invalidated, any other reactive
functions that recently called it are also marked as
invalidated. In this way, invalidations ripple through
the functions that depend on each other.
See the
http://rstudio.github.com/shiny/tutorial/{Shiny
tutorial} for more information about reactive functions.