shiny/man/registerInputHandler.Rd

\name{registerInputHandler}
\alias{registerInputHandler}
\title{Register an Input Handler}
\usage{
  registerInputHandler(type, fun, force = FALSE)
}
\arguments{
  \item{type}{The type for which the handler should be
  added}

  \item{fun}{The handler function. This is the function
  that will be used to parse the data delivered from the
  client before it is available in the \code{input}
  variable. The function will be called with the following
  three parameters: \enumerate{ \item{The value of this
  input as provided by the client, deserialized using
  RJSONIO.} \item{The \code{shinysession} in which the
  input exists.} \item{The name of the input.} }}

  \item{force}{If \code{TRUE}, will overwrite any existing
  handler without warning.}
}
\description{
  Adds an input handler for data of this type. When called,
  Shiny will use the function provided to refine the data
  passed back from the client (after being deserialized by
  RJSONIO) before making it available in the \code{input}
  variable of the \code{server.R} file.
}
\details{
  This function will register the handler for the duration
  of the R process (unless Shiny is explicitly reloaded).
  For that reason, the \code{type} used should be very
  specific to this package to minimize the risk of
  colliding with another Shiny package which might use this
  data type name. We recommend the format of
  "packageName.widgetName".

  Currently Shiny registers the following handlers:
  \code{shiny.matrix}, \code{shiny.number}, and
  \code{shiny.date}.

  The \code{type} of a custom Shiny Input widget will be
  deduced using the \code{getType()} JavaScript function on
  the registered Shiny inputBinding.
}
\seealso{
  \code{\link{removeInputHandler}}
}