There are a number of global options that affect Shiny's behavior. These can
be set with (for example) options(shiny.trace=TRUE)
.
A boolean which controls the default behavior
when an app is run. See runApp
for more information.
A port number that Shiny will listen on. See
runApp
for more information.
Print messages sent between the R server and the web
browser client to the R console. This is useful for debugging. Possible
values are "send"
(only print messages sent to the client),
"recv"
(only print messages received by the server), TRUE
(print all messages), or FALSE
(default; don't print any of these
messages).
If 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.
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).
If TRUE
, enable logging of reactive events,
which can be viewed later with the showReactLog
function.
This incurs a substantial performance penalty and should not be used in
production.
This is used to disable graphical rendering by the
Cairo package, if it is installed. See plotPNG
for more
information.
This is a number which specifies the maximum web request size, which serves as a size limit for file uploads. If unset, the maximum request size defaults to 5MB.
Normally, invoking a reactive
outside of a reactive context (or isolate()
) results in
an error. If this is TRUE
, don't error in these cases. This
should only be used for debugging or demonstrations of reactivity at the
console.
The IP address that Shiny should listen on. See
runApp
for more information.
The number of digits to use when converting numbers to JSON format to send to the client web browser.
If this is TRUE
or unset (the default), then
Shiny will use minified JavaScript (shiny.min.js
). If
FALSE
, then Shiny will use the un-minified JavaScript
(shiny.js
); this can be useful during development.
This can be a function which is called when an error
occurs. For example, options(shiny.error=recover)
will result a
the debugger prompt when an error occurs.
CSS class names to use for tables.
This controls whether messages for
deprecated functions in Shiny will be printed. See
shinyDeprecated
for more information.
Controls whether "pretty" or full stack traces
are dumped to the console when errors occur during Shiny app execution.
The default is FALSE
(pretty stack traces).
If 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.
If TRUE
, then normal errors (i.e.
errors not wrapped in 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). The default is FALSE
(unsanitized
errors).If you want to sanitize errors in general, but you DO want a
particular error e
to get displayed to the user, then set this option
to TRUE
and use stop(safeError(e))
for errors you want the
user to see.
If TRUE
, then enable features for testing Shiny
applications. If FALSE
(the default), do not enable those features.