shiny/man/shinyOptions.Rd

% Generated by roxygen2: do not edit by hand
% Please edit documentation in R/shiny-options.R
\name{getShinyOption}
\alias{getShinyOption}
\alias{shinyOptions}
\alias{shiny-options}
\title{Get or set Shiny options}
\usage{
getShinyOption(name, default = NULL)

shinyOptions(...)
}
\arguments{
\item{name}{Name of an option to get.}

\item{default}{Value to be returned if the option is not currently set.}

\item{...}{Options to set, with the form \code{name = value}.}
}
\description{
\code{getShinyOption()} retrieves the value of a Shiny option. \code{shinyOptions()}
sets the value of Shiny options; it can also be used to return a list of all
currently-set Shiny options.
}
\section{Scope}{

There is a global option set which is available by default. When a Shiny
application is run with \code{\link[=runApp]{runApp()}}, that option set is duplicated and the
new option set is available for getting or setting values. If options
are set from \code{global.R}, \code{app.R}, \code{ui.R}, or \code{server.R}, or if they are set
from inside the server function, then the options will be scoped to the
application. When the application exits, the new option set is discarded and
the global option set is restored.
}

\section{Options}{

There are a number of global options that affect Shiny's behavior. These can
be set globally with \code{options()} or locally (for a single app) with
\code{shinyOptions()}.

\describe{
\item{shiny.autoreload (defaults to \code{FALSE})}{If \code{TRUE} when a Shiny app is launched, the
app directory will be continually monitored for changes to files that
have the extensions: r, htm, html, js, css, png, jpg, jpeg, gif. If any
changes are detected, all connected Shiny sessions are reloaded. This
allows for fast feedback loops when tweaking Shiny UI.\preformatted{Since monitoring for changes is expensive (we simply poll for last
modified times), this feature is intended only for development.

You can customize the file patterns Shiny will monitor by setting the
shiny.autoreload.pattern option. For example, to monitor only ui.R:
`options(shiny.autoreload.pattern = glob2rx("ui.R"))`

The default polling interval is 500 milliseconds. You can change this
by setting e.g. `options(shiny.autoreload.interval = 2000)` (every
two seconds).}
}

\item{shiny.deprecation.messages (defaults to \code{TRUE})}{This controls whether messages for
deprecated functions in Shiny will be printed. See
\code{\link[=shinyDeprecated]{shinyDeprecated()}} for more information.}
\item{shiny.error (defaults to \code{NULL})}{This can be a function which is called when an error
occurs. For example, \code{options(shiny.error=recover)} will result a
the debugger prompt when an error occurs.}
\item{shiny.fullstacktrace (defaults to \code{FALSE})}{Controls whether "pretty" (\code{FALSE}) or full
stack traces (\code{TRUE}) are dumped to the console when errors occur during Shiny app execution.
Pretty stack traces attempt to only show user-supplied code, but this pruning can't always
be done 100\% correctly.}
\item{shiny.host (defaults to \code{"127.0.0.1"})}{The IP address that Shiny should listen on. See
\code{\link[=runApp]{runApp()}} for more information.}
\item{shiny.jquery.version (defaults to \code{3})}{The major version of jQuery to use.
Currently only values of \code{3} or \code{1} are supported. If \code{1}, then jQuery 1.12.4 is used. If \code{3},
then jQuery 3.4.1 is used.}
\item{shiny.json.digits (defaults to \code{16})}{The number of digits to use when converting
numbers to JSON format to send to the client web browser.}
\item{shiny.launch.browser (defaults to \code{interactive()})}{A boolean which controls the default behavior
when an app is run. See \code{\link[=runApp]{runApp()}} for more information.}
\item{shiny.maxRequestSize (defaults to 5MB)}{This is a number which specifies the maximum
web request size, which serves as a size limit for file uploads.}
\item{shiny.minified (defaults to \code{TRUE})}{By default
Whether or not to include Shiny's JavaScript as a minified (\code{shiny.min.js})
or un-minified (\code{shiny.js}) file. The un-minified version is larger,
but can be helpful for development and debugging.}
\item{shiny.port (defaults to a random open port)}{A port number that Shiny will listen on. See
\code{\link[=runApp]{runApp()}} for more information.}
\item{shiny.reactlog (defaults to \code{FALSE})}{If \code{TRUE}, enable logging of reactive events,
which can be viewed later with the \code{\link[=reactlogShow]{reactlogShow()}} function.
This incurs a substantial performance penalty and should not be used in
production.}
\item{shiny.sanitize.errors (defaults to \code{FALSE})}{If \code{TRUE}, then normal errors (i.e.
errors not wrapped in \code{safeError}) won't show up in the app; a simple
generic error message is printed instead (the error and strack trace printed
to the console remain unchanged). If you want to sanitize errors in general, but you DO want a
particular error \code{e} to get displayed to the user, then set this option
to \code{TRUE} and use \code{stop(safeError(e))} for errors you want the
user to see.}
\item{shiny.stacktraceoffset (defaults to \code{TRUE})}{If \code{TRUE}, then Shiny's printed stack
traces will display srcrefs one line above their usual location. This is
an arguably more intuitive arrangement for casual R users, as the name
of a function appears next to the srcref where it is defined, rather than
where it is currently being called from.}
\item{shiny.suppressMissingContextError (defaults to \code{FALSE})}{Normally, invoking a reactive
outside of a reactive context (or \code{\link[=isolate]{isolate()}}) results in
an error. If this is \code{TRUE}, don't error in these cases. This
should only be used for debugging or demonstrations of reactivity at the
console.}
\item{shiny.testmode (defaults to \code{FALSE})}{If \code{TRUE}, then various features for testing Shiny
applications are enabled.}
\item{shiny.trace (defaults to \code{FALSE})}{Print messages sent between the R server and the web
browser client to the R console. This is useful for debugging. Possible
values are \code{"send"} (only print messages sent to the client),
\code{"recv"} (only print messages received by the server), \code{TRUE}
(print all messages), or \code{FALSE} (default; don't print any of these
messages).}
\item{shiny.usecairo (defaults to \code{TRUE})}{This is used to disable graphical rendering by the
Cairo package, if it is installed. See \code{\link[=plotPNG]{plotPNG()}} for more
information.}
}
}

\examples{
\dontrun{
shinyOptions(myOption = 10)
getShinyOption("myOption")
}
}