Files
shiny/R/server.R
Joe Cheng 3ff6aaa6db Add namespacing functionality
- Need to carefully review ShinySession, think about
  each and every public method and whether it should
  be passthrough or do something different for a
  namespaced session.

- It would be nice if we do the namespace splitting
  at the server.R level and actually have numerous
  reactivevalues objects for inputs, one for each
  namespace. This will make the reactive hooks for
  names() and reactiveValuesToList() correct, as
  right now they will oversubscribe if you're in a
  namespaced session. Also it would prevent outer
  sessions from seeing the values of their child
  namespaces. (Though is that good or bad...?)
2015-10-02 12:51:18 -07:00

738 lines
24 KiB
R

#' @include server-input-handlers.R
appsByToken <- Map$new()
# Provide a character representation of the WS that can be used
# as a key in a Map.
wsToKey <- function(WS) {
as.character(WS$socket)
}
.globals$clients <- function(req) NULL
clearClients <- function() {
.globals$clients <- function(req) NULL
}
registerClient <- function(client) {
.globals$clients <- append(.globals$clients, client)
}
.globals$resources <- list()
.globals$showcaseDefault <- 0
.globals$showcaseOverride <- FALSE
#' Resource Publishing
#'
#' Adds a directory of static resources to Shiny's web server, with the given
#' path prefix. Primarily intended for package authors to make supporting
#' JavaScript/CSS files available to their components.
#'
#' @param prefix The URL prefix (without slashes). Valid characters are a-z,
#' A-Z, 0-9, hyphen, period, and underscore; and must begin with a-z or A-Z.
#' For example, a value of 'foo' means that any request paths that begin with
#' '/foo' will be mapped to the given directory.
#' @param directoryPath The directory that contains the static resources to be
#' served.
#'
#' @details You can call \code{addResourcePath} multiple times for a given
#' \code{prefix}; only the most recent value will be retained. If the
#' normalized \code{directoryPath} is different than the directory that's
#' currently mapped to the \code{prefix}, a warning will be issued.
#'
#' @seealso \code{\link{singleton}}
#'
#' @examples
#' addResourcePath('datasets', system.file('data', package='datasets'))
#'
#' @export
addResourcePath <- function(prefix, directoryPath) {
prefix <- prefix[1]
if (!grepl('^[a-z][a-z0-9\\-_.]*$', prefix, ignore.case=TRUE, perl=TRUE)) {
stop("addResourcePath called with invalid prefix; please see documentation")
}
if (prefix %in% c('shared')) {
stop("addResourcePath called with the reserved prefix '", prefix, "'; ",
"please use a different prefix")
}
directoryPath <- normalizePath(directoryPath, mustWork=TRUE)
existing <- .globals$resources[[prefix]]
.globals$resources[[prefix]] <- list(directoryPath=directoryPath,
func=staticHandler(directoryPath))
}
resourcePathHandler <- function(req) {
if (!identical(req$REQUEST_METHOD, 'GET'))
return(NULL)
path <- req$PATH_INFO
match <- regexpr('^/([^/]+)/', path, perl=TRUE)
if (match == -1)
return(NULL)
len <- attr(match, 'capture.length')
prefix <- substr(path, 2, 2 + len - 1)
resInfo <- .globals$resources[[prefix]]
if (is.null(resInfo))
return(NULL)
suffix <- substr(path, 2 + len, nchar(path))
subreq <- as.environment(as.list(req, all.names=TRUE))
subreq$PATH_INFO <- suffix
subreq$SCRIPT_NAME <- paste(subreq$SCRIPT_NAME, substr(path, 1, 2 + len), sep='')
return(resInfo$func(subreq))
}
#' Define Server Functionality
#'
#' Defines the server-side logic of the Shiny application. This generally
#' involves creating functions that map user inputs to various kinds of output.
#' In older versions of Shiny, it was necessary to call \code{shinyServer()} in
#' the \code{server.R} file, but this is no longer required as of Shiny 0.10.
#' Now the \code{server.R} file may simply return the appropriate server
#' function (as the last expression in the code), without calling
#' \code{shinyServer()}.
#'
#' Call \code{shinyServer} from your application's \code{server.R}
#' file, passing in a "server function" that provides the server-side logic of
#' your application.
#'
#' The server function will be called when each client (web browser) first loads
#' the Shiny application's page. It must take an \code{input} and an
#' \code{output} parameter. Any return value will be ignored. It also takes an
#' optional \code{session} parameter, which is used when greater control is
#' needed.
#'
#' See the \href{http://rstudio.github.com/shiny/tutorial/}{tutorial} for more
#' on how to write a server function.
#'
#' @param func The server function for this application. See the details section
#' for more information.
#'
#' @examples
#' \dontrun{
#' # A very simple Shiny app that takes a message from the user
#' # and outputs an uppercase version of it.
#' shinyServer(function(input, output, session) {
#' output$uppercase <- renderText({
#' toupper(input$message)
#' })
#' })
#'
#'
#' # It is also possible for a server.R file to simply return the function,
#' # without calling shinyServer().
#' # For example, the server.R file could contain just the following:
#' function(input, output, session) {
#' output$uppercase <- renderText({
#' toupper(input$message)
#' })
#' }
#' }
#'
#' @export
shinyServer <- function(func) {
.globals$server <- list(func)
invisible(func)
}
decodeMessage <- function(data) {
readInt <- function(pos) {
packBits(rawToBits(data[pos:(pos+3)]), type='integer')
}
if (readInt(1) != 0x01020202L) {
# Treat message as UTF-8
charData <- rawToChar(data)
Encoding(charData) <- 'UTF-8'
return(jsonlite::fromJSON(charData, simplifyVector=FALSE))
}
i <- 5
parts <- list()
while (i <= length(data)) {
length <- readInt(i)
i <- i + 4
if (length != 0)
parts <- append(parts, list(data[i:(i+length-1)]))
else
parts <- append(parts, list(raw(0)))
i <- i + length
}
mainMessage <- decodeMessage(parts[[1]])
mainMessage$blobs <- parts[2:length(parts)]
return(mainMessage)
}
createAppHandlers <- function(httpHandlers, serverFuncSource) {
appvars <- new.env()
appvars$server <- NULL
sys.www.root <- system.file('www', package='shiny')
# This value, if non-NULL, must be present on all HTTP and WebSocket
# requests as the Shiny-Shared-Secret header or else access will be
# denied (403 response for HTTP, and instant close for websocket).
sharedSecret <- getOption('shiny.sharedSecret')
appHandlers <- list(
http = joinHandlers(c(
sessionHandler,
httpHandlers,
sys.www.root,
resourcePathHandler,
reactLogHandler)),
ws = function(ws) {
if (!is.null(sharedSecret)
&& !identical(sharedSecret, ws$request$HTTP_SHINY_SHARED_SECRET)) {
ws$close()
return(TRUE)
}
shinysession <- ShinySession$new(ws)
appsByToken$set(shinysession$token, shinysession)
shinysession$setShowcase(.globals$showcaseDefault)
ws$onMessage(function(binary, msg) {
withReactiveDomain(shinysession, {
# To ease transition from websockets-based code. Should remove once we're stable.
if (is.character(msg))
msg <- charToRaw(msg)
if (isTRUE(getOption('shiny.trace'))) {
if (binary)
message("RECV ", '$$binary data$$')
else
message("RECV ", rawToChar(msg))
}
if (identical(charToRaw("\003\xe9"), msg))
return()
msg <- decodeMessage(msg)
# Do our own list simplifying here. sapply/simplify2array give names to
# character vectors, which is rarely what we want.
if (!is.null(msg$data)) {
for (name in names(msg$data)) {
val <- msg$data[[name]]
splitName <- strsplit(name, ':')[[1]]
if (length(splitName) > 1) {
msg$data[[name]] <- NULL
if (!inputHandlers$containsKey(splitName[[2]])){
# No input handler registered for this type
stop("No handler registered for for type ", name)
}
msg$data[[ splitName[[1]] ]] <-
inputHandlers$get(splitName[[2]])(
val,
shinysession,
splitName[[1]] )
}
else if (is.list(val) && is.null(names(val))) {
val_flat <- unlist(val, recursive = TRUE)
if (is.null(val_flat)) {
# This is to assign NULL instead of deleting the item
msg$data[name] <- list(NULL)
} else {
msg$data[[name]] <- val_flat
}
}
}
}
switch(
msg$method,
init = {
serverFunc <- withReactiveDomain(NULL, serverFuncSource())
if (!identicalFunctionBodies(serverFunc, appvars$server)) {
appvars$server <- serverFunc
if (!is.null(appvars$server))
{
# Tag this function as the Shiny server function. A debugger may use this
# tag to give this function special treatment.
# It's very important that it's appvars$server itself and NOT a copy that
# is invoked, otherwise new breakpoints won't be picked up.
attr(appvars$server, "shinyServerFunction") <- TRUE
registerDebugHook("server", appvars, "Server Function")
}
}
# Check for switching into/out of showcase mode
if (.globals$showcaseOverride &&
exists(".clientdata_url_search", where = msg$data)) {
mode <- showcaseModeOfQuerystring(msg$data$.clientdata_url_search)
if (!is.null(mode))
shinysession$setShowcase(mode)
}
shinysession$manageInputs(msg$data)
# The client tells us what singletons were rendered into
# the initial page
if (!is.null(msg$data$.clientdata_singletons)) {
shinysession$singletons <- strsplit(
msg$data$.clientdata_singletons, ',')[[1]]
}
local({
args <- list(
input=shinysession$input,
output=.createOutputWriter(shinysession))
# The clientData and session arguments are optional; check if
# each exists
if ('clientData' %in% names(formals(serverFunc)))
args$clientData <- shinysession$clientData
if ('session' %in% names(formals(serverFunc)))
args$session <- shinysession
withReactiveDomain(shinysession, {
do.call(appvars$server, args)
})
})
},
update = {
shinysession$manageInputs(msg$data)
},
shinysession$dispatch(msg)
)
shinysession$manageHiddenOutputs()
if (exists(".shiny__stdout", globalenv()) &&
exists("HTTP_GUID", ws$request)) {
# safe to assume we're in shiny-server
shiny_stdout <- get(".shiny__stdout", globalenv())
# eNter a flushReact
writeLines(paste("_n_flushReact ", get("HTTP_GUID", ws$request),
" @ ", sprintf("%.3f", as.numeric(Sys.time())),
sep=""), con=shiny_stdout)
flush(shiny_stdout)
flushReact()
# eXit a flushReact
writeLines(paste("_x_flushReact ", get("HTTP_GUID", ws$request),
" @ ", sprintf("%.3f", as.numeric(Sys.time())),
sep=""), con=shiny_stdout)
flush(shiny_stdout)
} else {
flushReact()
}
lapply(appsByToken$values(), function(shinysession) {
shinysession$flushOutput()
NULL
})
})
})
ws$onClose(function() {
shinysession$wsClosed()
appsByToken$remove(shinysession$token)
})
return(TRUE)
}
)
return(appHandlers)
}
getEffectiveBody <- function(func) {
# Note: NULL values are OK. isS4(NULL) returns FALSE, body(NULL)
# returns NULL.
if (isS4(func) && class(func) == "functionWithTrace")
body(func@original)
else
body(func)
}
identicalFunctionBodies <- function(a, b) {
identical(getEffectiveBody(a), getEffectiveBody(b))
}
handlerManager <- HandlerManager$new()
addSubApp <- function(appObj, autoRemove = TRUE) {
path <- createUniqueId(16, "/app")
appHandlers <- createAppHandlers(appObj$httpHandler, appObj$serverFuncSource)
# remove the leading / from the path so a relative path is returned
# (needed for the case where the root URL for the Shiny app isn't /, such
# as portmapped URLs)
finalPath <- paste(
substr(path, 2, nchar(path)),
"/?w=", workerId(),
"&__subapp__=1",
sep="")
handlerManager$addHandler(routeHandler(path, appHandlers$http), finalPath)
handlerManager$addWSHandler(routeWSHandler(path, appHandlers$ws), finalPath)
if (autoRemove) {
# If a session is currently active, remove this subapp automatically when
# the current session ends
onReactiveDomainEnded(getDefaultReactiveDomain(), function() {
removeSubApp(finalPath)
})
}
return(finalPath)
}
removeSubApp <- function(path) {
handlerManager$removeHandler(path)
handlerManager$removeWSHandler(path)
}
startApp <- function(appObj, port, host, quiet) {
appHandlers <- createAppHandlers(appObj$httpHandler, appObj$serverFuncSource)
handlerManager$addHandler(appHandlers$http, "/", tail = TRUE)
handlerManager$addWSHandler(appHandlers$ws, "/", tail = TRUE)
if (is.numeric(port) || is.integer(port)) {
if (!quiet) {
message('\n', 'Listening on http://', host, ':', port)
}
return(startServer(host, port, handlerManager$createHttpuvApp()))
} else if (is.character(port)) {
if (!quiet) {
message('\n', 'Listening on domain socket ', port)
}
mask <- attr(port, 'mask')
return(startPipeServer(port, mask, handlerManager$createHttpuvApp()))
}
}
# Run an application that was created by \code{\link{startApp}}. This
# function should normally be called in a \code{while(TRUE)} loop.
serviceApp <- function() {
if (timerCallbacks$executeElapsed()) {
for (shinysession in appsByToken$values()) {
shinysession$manageHiddenOutputs()
}
flushReact()
for (shinysession in appsByToken$values()) {
shinysession$flushOutput()
}
}
# If this R session is interactive, then call service() with a short timeout
# to keep the session responsive to user input
maxTimeout <- ifelse(interactive(), 100, 1000)
timeout <- max(1, min(maxTimeout, timerCallbacks$timeToNextEvent()))
service(timeout)
}
.shinyServerMinVersion <- '0.3.4'
#' Run Shiny Application
#'
#' Runs a Shiny application. This function normally does not return; interrupt R
#' to stop the application (usually by pressing Ctrl+C or Esc).
#'
#' The host parameter was introduced in Shiny 0.9.0. Its default value of
#' \code{"127.0.0.1"} means that, contrary to previous versions of Shiny, only
#' the current machine can access locally hosted Shiny apps. To allow other
#' clients to connect, use the value \code{"0.0.0.0"} instead (which was the
#' value that was hard-coded into Shiny in 0.8.0 and earlier).
#'
#' @param appDir The directory of the application. Should contain
#' \code{server.R}, plus, either \code{ui.R} or a \code{www} directory that
#' contains the file \code{index.html}. Alternately, instead of
#' \code{server.R} and \code{ui.R}, the directory may contain just
#' \code{app.R}. Defaults to the working directory. Instead of a directory,
#' this could be a list with \code{ui} and \code{server} components, or a
#' Shiny app object created by \code{\link{shinyApp}}.
#' @param port The TCP port that the application should listen on. If the
#' \code{port} is not specified, and the \code{shiny.port} option is set (with
#' \code{options(shiny.port = XX)}), then that port will be used. Otherwise,
#' use a random port.
#' @param launch.browser If true, the system's default web browser will be
#' launched automatically after the app is started. Defaults to true in
#' interactive sessions only. This value of this parameter can also be a
#' function to call with the application's URL.
#' @param host The IPv4 address that the application should listen on. Defaults
#' to the \code{shiny.host} option, if set, or \code{"127.0.0.1"} if not. See
#' Details.
#' @param workerId Can generally be ignored. Exists to help some editions of
#' Shiny Server Pro route requests to the correct process.
#' @param quiet Should Shiny status messages be shown? Defaults to FALSE.
#' @param display.mode The mode in which to display the application. If set to
#' the value \code{"showcase"}, shows application code and metadata from a
#' \code{DESCRIPTION} file in the application directory alongside the
#' application. If set to \code{"normal"}, displays the application normally.
#' Defaults to \code{"auto"}, which displays the application in the mode given
#' in its \code{DESCRIPTION} file, if any.
#'
#' @examples
#' \dontrun{
#' # Start app in the current working directory
#' runApp()
#'
#' # Start app in a subdirectory called myapp
#' runApp("myapp")
#' }
#'
#' ## Only run this example in interactive R sessions
#' if (interactive()) {
#' # Apps can be run without a server.r and ui.r file
#' runApp(list(
#' ui = bootstrapPage(
#' numericInput('n', 'Number of obs', 100),
#' plotOutput('plot')
#' ),
#' server = function(input, output) {
#' output$plot <- renderPlot({ hist(runif(input$n)) })
#' }
#' ))
#'
#'
#' # Running a Shiny app object
#' app <- shinyApp(
#' ui = bootstrapPage(
#' numericInput('n', 'Number of obs', 100),
#' plotOutput('plot')
#' ),
#' server = function(input, output) {
#' output$plot <- renderPlot({ hist(runif(input$n)) })
#' }
#' )
#' runApp(app)
#' }
#' @export
runApp <- function(appDir=getwd(),
port=getOption('shiny.port'),
launch.browser=getOption('shiny.launch.browser',
interactive()),
host=getOption('shiny.host', '127.0.0.1'),
workerId="", quiet=FALSE,
display.mode=c("auto", "normal", "showcase")) {
on.exit({
handlerManager$clear()
}, add = TRUE)
if (is.null(host) || is.na(host))
host <- '0.0.0.0'
# Make warnings print immediately
ops <- options(warn = 1)
on.exit(options(ops), add = TRUE)
workerId(workerId)
if (nzchar(Sys.getenv('SHINY_PORT'))) {
# If SHINY_PORT is set, we're running under Shiny Server. Check the version
# to make sure it is compatible. Older versions of Shiny Server don't set
# SHINY_SERVER_VERSION, those will return "" which is considered less than
# any valid version.
ver <- Sys.getenv('SHINY_SERVER_VERSION')
if (utils::compareVersion(ver, .shinyServerMinVersion) < 0) {
warning('Shiny Server v', .shinyServerMinVersion,
' or later is required; please upgrade!')
}
}
# Showcase mode is disabled by default; it must be explicitly enabled in
# either the DESCRIPTION file for directory-based apps, or via
# the display.mode parameter. The latter takes precedence.
setShowcaseDefault(0)
# If appDir specifies a path, and display mode is specified in the
# DESCRIPTION file at that path, apply it here.
if (is.character(appDir)) {
desc <- file.path.ci(appDir, "DESCRIPTION")
if (file.exists(desc)) {
con <- file(desc, encoding = checkEncoding(desc))
on.exit(close(con), add = TRUE)
settings <- read.dcf(con)
if ("DisplayMode" %in% colnames(settings)) {
mode <- settings[1,"DisplayMode"]
if (mode == "Showcase") {
setShowcaseDefault(1)
}
}
}
}
# If display mode is specified as an argument, apply it (overriding the
# value specified in DESCRIPTION, if any).
display.mode <- match.arg(display.mode)
if (display.mode == "normal")
setShowcaseDefault(0)
else if (display.mode == "showcase")
setShowcaseDefault(1)
require(shiny)
# determine port if we need to
if (is.null(port)) {
# Try up to 20 random ports. If we don't succeed just plow ahead
# with the final value we tried, and let the "real" startServer
# somewhere down the line fail and throw the error to the user.
#
# If we (think we) succeed, save the value as .globals$lastPort,
# and try that first next time the user wants a random port.
for (i in 1:20) {
if (!is.null(.globals$lastPort)) {
port <- .globals$lastPort
.globals$lastPort <- NULL
}
else {
# Try up to 20 random ports
port <- p_randomInt(3000, 8000)
}
# Test port to see if we can use it
tmp <- try(startServer(host, port, list()), silent=TRUE)
if (!inherits(tmp, 'try-error')) {
stopServer(tmp)
.globals$lastPort <- port
break
}
}
}
appParts <- as.shiny.appobj(appDir)
# Set up the onEnd before we call onStart, so that it gets called even if an
# error happens in onStart.
if (!is.null(appParts$onEnd))
on.exit(appParts$onEnd(), add = TRUE)
if (!is.null(appParts$onStart))
appParts$onStart()
server <- startApp(appParts, port, host, quiet)
on.exit({
stopServer(server)
}, add = TRUE)
if (!is.character(port)) {
# http://0.0.0.0/ doesn't work on QtWebKit (i.e. RStudio viewer)
browseHost <- if (identical(host, "0.0.0.0")) "127.0.0.1" else host
appUrl <- paste("http://", browseHost, ":", port, sep="")
if (is.function(launch.browser))
launch.browser(appUrl)
else if (launch.browser)
utils::browseURL(appUrl)
} else {
appUrl <- NULL
}
# call application hooks
callAppHook("onAppStart", appUrl)
on.exit({
callAppHook("onAppStop", appUrl)
}, add = TRUE)
.globals$retval <- NULL
.globals$stopped <- FALSE
shinyCallingHandlers(
while (!.globals$stopped) {
serviceApp()
Sys.sleep(0.001)
}
)
return(.globals$retval)
}
#' Stop the currently running Shiny app
#'
#' Stops the currently running Shiny app, returning control to the caller of
#' \code{\link{runApp}}.
#'
#' @param returnValue The value that should be returned from
#' \code{\link{runApp}}.
#'
#' @export
stopApp <- function(returnValue = NULL) {
.globals$retval <- returnValue
.globals$stopped <- TRUE
httpuv::interrupt()
}
#' Run Shiny Example Applications
#'
#' Launch Shiny example applications, and optionally, your system's web browser.
#'
#' @param example The name of the example to run, or \code{NA} (the default) to
#' list the available examples.
#' @param port The TCP port that the application should listen on. Defaults to
#' choosing a random port.
#' @param launch.browser If true, the system's default web browser will be
#' launched automatically after the app is started. Defaults to true in
#' interactive sessions only.
#' @param host The IPv4 address that the application should listen on. Defaults
#' to the \code{shiny.host} option, if set, or \code{"127.0.0.1"} if not.
#' @param display.mode The mode in which to display the example. Defaults to
#' \code{showcase}, but may be set to \code{normal} to see the example without
#' code or commentary.
#'
#' @examples
#' ## Only run this example in interactive R sessions
#' if (interactive()) {
#' # List all available examples
#' runExample()
#'
#' # Run one of the examples
#' runExample("01_hello")
#'
#' # Print the directory containing the code for all examples
#' system.file("examples", package="shiny")
#' }
#' @export
runExample <- function(example=NA,
port=NULL,
launch.browser=getOption('shiny.launch.browser',
interactive()),
host=getOption('shiny.host', '127.0.0.1'),
display.mode=c("auto", "normal", "showcase")) {
examplesDir <- system.file('examples', package='shiny')
dir <- resolve(examplesDir, example)
if (is.null(dir)) {
if (is.na(example)) {
errFun <- message
errMsg <- ''
}
else {
errFun <- stop
errMsg <- paste('Example', example, 'does not exist. ')
}
errFun(errMsg,
'Valid examples are "',
paste(list.files(examplesDir), collapse='", "'),
'"')
}
else {
runApp(dir, port = port, host = host, launch.browser = launch.browser,
display.mode = display.mode)
}
}