shiny/man/observe.Rd

\name{observe}
\alias{observe}
\title{Observe}
\usage{
  observe(func)
}
\arguments{
  \item{func}{The function to observe. It must not have any
  parameters. Any return value from this function will be
  ignored.}
}
\description{
  Creates an observer from the given function. An observer
  is like a reactive function in that it can read reactive
  values and call reactive functions, and will
  automatically re-execute when those dependencies change.
  But unlike reactive functions, it doesn't yield a result
  and can't be used as an input to other reactive
  functions. Thus, observers are only useful for their side
  effects (for example, performing I/O).
}