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R/Fire.R
In fiery: A Lightweight and Flexible Web Framework
#' @include aaa.R
#' @include HandlerStack.R
#' @include loggers.R
NULL
#' Generate a New App Object
#'
#' @description
#' The Fire generator creates a new `Fire`-object, which is the class containing
#' all the app logic. The class is based on the [R6][R6::R6Class] OO-system and
#' is thus reference-based with methods and data attached to each object, in
#' contrast to the more well known S3 and S4 systems. A `fiery` server is event
#' driven, which means that it is build up and manipulated by adding event
#' handlers and triggering events. To learn more about the `fiery` event model,
#' read the [event vignette](https://fiery.data-imaginist.com/articles/events.html).
#' `fiery` servers can be modified directly or by attaching plugins. As with
#' events, [plugins has its own vignette](https://fiery.data-imaginist.com/articles/plugins.html).
#'
#' ## Initialization
#' A new 'Fire'-object is initialized using the `new()` method on the generator:
#'
#' \tabular{l}{
#' `app <- Fire$new(host = '127.0.0.1', port = 8080L)`
#' }
#'
#' ## Copying
#'
#' As `Fire` objects are using reference semantics new copies of an app cannot
#' be made simply be assigning it to a new variable. If a true copy of a `Fire`
#' object is desired, use the `clone()` method.
#'
#' @importFrom R6 R6Class
#' @importFrom httpuv startServer service startDaemonizedServer stopDaemonizedServer stopServer
#' @importFrom uuid UUIDgenerate
#' @importFrom utils browseURL
#' @importFrom later later
#' @importFrom stats setNames
#' @importFrom reqres Request
#' @importFrom stringi stri_pad_left
#'
#' @export
#'
#' @examples
#' # Create a New App
#' app <- Fire$new(port = 4689)
#'
#' # Setup the data every time it starts
#' app$on('start', function(server, ...) {
#' server$set_data('visits', 0)
#' server$set_data('cycles', 0)
#' })
#'
#' # Count the number of cycles
#' app$on('cycle-start', function(server, ...) {
#' server$set_data('cycles', server$get_data('cycles') + 1)
#' })
#'
#' # Count the number of requests
#' app$on('before-request', function(server, ...) {
#' server$set_data('visits', server$get_data('visits') + 1)
#' })
#'
#' # Handle requests
#' app$on('request', function(server, ...) {
#' list(
#' status = 200L,
#' headers = list('Content-Type' = 'text/html'),
#' body = paste('This is indeed a test. You are number', server$get_data('visits'))
#' )
#' })
#'
#' # Show number of requests in the console
#' app$on('after-request', function(server, ...) {
#' message(server$get_data('visits'))
#' flush.console()
#' })
#'
#' # Terminate the server after 300 cycles
#' app$on('cycle-end', function(server, ...) {
#' if (server$get_data('cycles') > 300) {
#' message('Ending...')
#' flush.console()
#' server$extinguish()
#' }
#' })
#'
#' # Be polite
#' app$on('end', function(server) {
#' message('Goodbye')
#' flush.console()
#' })
#'
#' \dontrun{
#' app$ignite(showcase = TRUE)
#' }
#'
Fire <- R6Class('Fire',
public = list(
# Methods
#' @description Create a new `Fire` app
#' @param host A string overriding the default host
#' @param port An port number overriding the default port
#' @return A `Fire` object
initialize = function(host = '127.0.0.1', port = 8080) {
self$host <- host
self$port <- port
private$data <- new.env(parent = emptyenv())
private$handlers <- new.env(parent = emptyenv())
private$websockets <- new.env(parent = emptyenv())
private$client_id <- client_to_id
private$DELAY <- DelayStack$new(self)
private$TIME <- TimeStack$new(self)
private$ASYNC <- AsyncStack$new(self)
private$LOG_QUEUE <- DelayStack$new(self)
},
#' @description Human readable description of the app
#' @param ... ignored
#' @return A character vector
format = function(...) {
text <- c(
'\U0001f525 A fiery webserver',
'\U0001f525 \U0001f4a5 \U0001f4a5 \U0001f4a5'
)
mat <- matrix(c('Running on', ': ', paste0(self$host, ':', self$port, self$root)), ncol = 3)
plugins <- names(private$pluginList)
if (is.null(plugins)) plugins <- 'none'
mat <- rbind(mat, c('Plugins attached', ': ', plugins[1]))
mat <- rbind(mat, matrix(c(rep(' ', (length(plugins) - 1)*2), plugins[-1]), ncol = 3))
handlers <- lapply(private$handlers, function(x) x$length())
if (length(handlers) == 0) {
mat <- rbind(mat, c('Event handlers added', ': ', 'none'))
} else {
mat <- rbind(mat, c('Event handlers added', '', ''))
order <- match(names(handlers), private$privateTriggers)
order[is.na(order)] <- seq_len(sum(is.na(order))) + max(order, na.rm = TRUE)
handlers <- handlers[order(order)]
mat <- rbind(mat, matrix(c(names(handlers), rep(': ', length(handlers)), as.character(unlist(handlers))), ncol = 3))
}
mat[, 1] <- stri_pad_left(mat[, 1], max(nchar(mat[,1])))
c(text, paste0('\U0001f525 ', apply(mat, 1, paste, collapse = '')))
},
#' @description Begin running the server. Will trigger the `start` event
#' @param block Should the console be blocked while running (alternative is to run in the background)
#' @param showcase Should the default browser open up at the server address
#' @param ... Arguments passed on to the `start` handler
#' @param silent Should startup messaging by silenced
ignite = function(block = TRUE, showcase = FALSE, ..., silent = FALSE) {
private$run(block = block, showcase = showcase, ..., silent = silent)
invisible(NULL)
},
#' @description Synonymous method to `ignite()`
#' @param ... passed on to `ignite()`
start = function(...) {
self$ignite(...)
},
#' @description Resume a session. This is equivalent to `ignite()` but will also trigger the `resume` event
#' @param ... passed on to `ignite()`
reignite = function(...) {
private$run(..., resume = TRUE)
invisible(NULL)
},
#' @description Synonymous method to `reignite()`
#' @param ... passed on to `ignite()`
resume = function(...) {
self$reignite(...)
},
#' @description Stop the server. Will trigger the `end` event
extinguish = function() {
if (private$running) {
if (!is.null(private$server)) {
if (private$nb_cycle) {
warning('Cannot stop server from within a non-blocking event cycle', call. = FALSE)
return(invisible(NULL))
} else {
private$running <- FALSE
private$p_trigger('end', server = self)
stopDaemonizedServer(private$server)
private$server <- NULL
self$log('stop', paste0(self$host, ':', self$port, self$root))
}
} else {
private$quitting <- TRUE
}
}
invisible(NULL)
},
#' @description Synonymous method to `extinguish()`
stop = function() {
self$extinguish()
},
#' @description Add a handler to an event. See the [*The event cycle in fiery* vignette](https://fiery.data-imaginist.com/articles/events.html) for more information.
#' @param event The name of the event that should trigger the handler
#' @param handler The handler function that should be triggered
#' @param pos The position in the handler stack to place it at. `NULL` will place it at the end.
#' @return A unique string identifying the handler
on = function(event, handler, pos = NULL) {
check_string(event)
check_function(handler)
handlerId <- UUIDgenerate()
private$handlerMap[[handlerId]] <- event
private$add_handler(event, handler, pos, handlerId)
invisible(handlerId)
},
#' @description Remove an event handler from the app.
#' @param handlerId The unique id identifying the handler
off = function(handlerId) {
check_string(handlerId)
private$remove_handler(handlerId)
private$handlerMap[[handlerId]] <- NULL
invisible(NULL)
},
#' @description Trigger an event in the app. This will cause any handler attached to the event to be called. See the [*The event cycle in fiery* vignette](https://fiery.data-imaginist.com/articles/events.html) for more information.
#' @param event The name of the event
#' @param ... Arguments passed on to the handlers
#' @return A named list containing the return values of all handlers attached to the event
trigger = function(event, ...) {
check_string(event)
if (event %in% private$privateTriggers) {
cli::cli_abort('{val {event}} and other protected events cannot be triggered manually')
} else {
private$p_trigger(event, server = self, ...)
}
},
#' @description Send a Websocket message to a client. Will trigger the `send` event.
#' @param message The message to send
#' @param id The id of the client to send to. If missing, the message will be send to all clients
send = function(message, id) {
private$send_ws(message, id)
private$p_trigger('send', server = self, id = id, message = message)
invisible(NULL)
},
#' @description Close a Websocket connection. Will trigger the `websocket-closed` event
#' @param id The id of the client to close the websocket connection to
close_ws_con = function(id) {
check_string(id)
ws <- private$websockets[[id]]
if (!is.null(ws)) {
private$close_ws(id)
}
},
#' @description Attach a plugin to the app. See the [*Creating and using fiery plugins* vignette](https://fiery.data-imaginist.com/articles/plugins.html) for more information
#' @param plugin The plugin to attach
#' @param ... Arguments to pass into the plugins `on_attach()` method
#' @param force If the plugin has already been attached an error is thrown, unless `force = TRUE` which tells the app to reattach it
attach = function(plugin, ..., force = FALSE) {
name <- plugin$name
check_string(name, arg = 'plugin$name')
if (!force && self$has_plugin(name)) {
cli::cli_abort(c(
'The {.arg {name}} plugin is already loaded.',
i = 'Use {.code force = TRUE} to reapply it.'
))
}
requires <- plugin$require
if (!is.null(requires)) {
check_character(requires)
exists <- vapply(requires, self$has_plugin, logical(1))
if (!all(exists)) {
cli::cli_abort('The {.arg {name}} plugin requires the following {cli::qty(requires[!exists])} plugin{?s}: {requires[!exists]}')
}
}
try_fetch(
plugin$on_attach(self, ...),
error = function(cnd) {
cli::cli_abort('The {.arg {name}} plugin failed to attach to the app', parent = cnd)
}
)
private$add_plugin(plugin, name)
invisible(NULL)
},
#' @description Check if the app has a plugin attached
#' @param name The name of the plugin
#' @return A boolean indicating if the given plugin is already attached
has_plugin = function(name) {
name %in% names(private$pluginList)
},
#' @description Add a global http header that will be applied to all responses
#' @param name The name of the header
#' @param value The value of the header. Use `NULL` to remove the global header
header = function(name, value) {
check_string(name)
if (missing(value)) return(private$headers[[name]])
check_string(value, allow_null = TRUE)
private$headers[[name]] <- value
invisible(NULL)
},
#' @description Add data to the global data store
#' @param name The name identifying the data
#' @param value The data to add
set_data = function(name, value) {
check_string(name)
assign(name, value, envir = private$data)
invisible(NULL)
},
#' @description Retrieve data from the global data store
#' @param name The name identifying the data
#' @return The data requested. Returns `NULL` if the store does not contain the requested data
get_data = function(name) {
check_string(name)
private$data[[name]]
},
#' @description Remove data from the global data store
#' @param name The name identifying the data to be removed
remove_data = function(name) {
check_string(name)
rm(list = name, envir = private$data)
invisible(NULL)
},
#' @description Add a timed evaluation that will be evaluated after the given number of seconds. See the [*Delaying code execution in Fiery* vignette](https://fiery.data-imaginist.com/articles/delayed.html) for more information
#' @param expr The expression to evaluate when the time has passed
#' @param then A handler to call once `expr` has been evaluated
#' @param after The time in second to wait before evaluating `expr`
#' @param loop Should `expr` be called repeatedly with the interval given by `after`
#' @return A unique id identifying the handler
time = function(expr, then, after, loop = FALSE) {
private$TIME$add(substitute(expr), then, after, loop, substituted = TRUE)
},
#' @description Remove a timed evaluation
#' @param id The unique id identifying the handler
remove_time = function(id) {
private$TIME$remove(id)
},
#' @description Add a delayed evaluation to be evaluated immediately at the end of the loop cycle. See the [*Delaying code execution in Fiery* vignette](https://fiery.data-imaginist.com/articles/delayed.html) for more information
#' @param expr The expression to evaluate at the end of the cycle
#' @param then A handler to call once `expr` has been evaluated
#' @return A unique id identifying the handler
delay = function(expr, then) {
private$DELAY$add(substitute(expr), then, substituted = TRUE)
},
#' @description Remove a delayed evaluation
#' @param id The unique id identifying the handler
remove_delay = function(id) {
private$DELAY$remove(id)
},
#' @description Add an asynchronous evaluation to be evaluated in another process without blocking the server. See the [*Delaying code execution in Fiery* vignette](https://fiery.data-imaginist.com/articles/delayed.html) for more information
#' @param expr The expression to evaluate at the end of the cycle
#' @param then A handler to call once `expr` has been evaluated
#' @return A unique id identifying the handler
async = function(expr, then) {
private$ASYNC$add(substitute(expr), then, substituted = TRUE)
},
#' @description Remove an async evaluation
#' @param id The unique id identifying the handler
remove_async = function(id) {
private$ASYNC$remove(id)
},
#' @description Sets the function that converts an HTTP request into a specific client id
#' @param converter A function with the argument `request`
set_client_id_converter = function(converter) {
check_args(converter, 'request')
private$client_id <- converter
invisible(NULL)
},
#' @description Sets the logging function to use
#' @param logger A function with the arguments `event`, `message`, `request`, and `...`
set_logger = function(logger) {
check_function(logger)
check_args(logger, c('event', 'message', 'request', '...'))
private$logger <- list(logger)
invisible(NULL)
},
#' @description Log a message with the logger attached to the app. See [loggers] for build in functionality
#' @param event The event associated with the message
#' @param message The message to log
#' @param request The `Request` object associated with the message, if any.
#' @param ... Additional arguments passed on to the logger.
log = function(event, message, request = NULL, ...) {
time <- Sys.time()
force(message)
if (private$running) {
private$LOG_QUEUE$add(NULL, function(...) private$logger[[1]](event, message, request, time, ...))
} else {
private$logger[[1]](event, message, request, time, ...)
}
invisible(NULL)
},
#' @description Test if an app is running
is_running = function() {
private$running
},
#' @description Send a request directly to the request logic of a non-running app. Only intended for testing the request logic
#' @param request The request to send
test_request = function(request) {
private$request_logic(request)
},
#' @description Send a request directly to the header logic of a non-running app. Only intended for testing the request logic
#' @param request The request to send
test_header = function(request) {
private$header_logic(request)
},
#' @description Send a message directly **to** the message logic of a non-running app. Only intended for testing the websocket logic
#' @param request The request to use to establish the connection
#' @param binary Is the message send in binary or character format
#' @param message The message to send. If `binary = FALSE` a character vector, if `binary = TRUE` a raw vector
#' @param withClose Should the websocket connection be closed at the end by the client
test_message = function(request, binary, message, withClose = TRUE) {
id <- private$client_id(request)
message_fun <- private$message_logic(id, request)
message_fun(binary, message)
if (withClose) {
close_fun <- private$close_ws_logic(id, request)
close_fun()
}
},
#' @description Send a message directly **from** a non-running app. Only intended for testing the websocket logic
#' @param request The request to use to establish the connection
#' @param message The message to send from the app
#' @param close Should the websocket connection be closed at the end by the server
test_websocket = function(request, message, close = TRUE) {
ws <- list(
request = request,
onMessage = function(func) {},
onClose = function(func) {},
send = function(message) {message(message)},
close = function() {message('closing')}
)
private$websocket_logic(ws)
self$send(message, private$client_id(request))
if (close) private$close_ws(private$client_id(request))
}
),
active = list(
#' @field host A string giving a valid IPv4 address owned by the server, or `'0.0.0.0'` to listen on all addresses. The default is `'127.0.0.1'`
host = function(address) {
if (missing(address)) return(private$HOST)
check_string(address)
private$HOST <- address
},
#' @field port An integer giving the port number the server should listen on (defaults to `8080L`)
port = function(n) {
if (missing(n)) return(private$PORT)
check_number_whole(n, min = 1)
private$PORT <- n
},
#' @field refresh_rate The interval in seconds between run cycles when running a blocking server (defaults to `0.001`)
refresh_rate = function(rate) {
if (missing(rate)) return(private$REFRESHRATE)
check_number_decimal(rate)
private$REFRESHRATE <- rate
},
#' @field refresh_rate_nb The interval in seconds between run cycles when running a non-blocking server (defaults to `1`)
refresh_rate_nb = function(rate) {
if (missing(rate)) return(private$REFRESHRATENB)
check_number_decimal(rate)
private$REFRESHRATENB <- rate
},
#' @field trigger_dir A valid folder where trigger files can be put when running a blocking server (defaults to `NULL`). See the [*The event cycle in fiery* vignette](https://fiery.data-imaginist.com/articles/events.html) for more information.
trigger_dir = function(dir) {
if (missing(dir)) return(private$TRIGGERDIR)
check_dir(dir, allow_null = TRUE)
private$TRIGGERDIR <- dir
},
#' @field plugins A named list of the already attached plugins. **Read Only** - can only be modified using the `attach()` method.
plugins = function(plugin) {
if (!missing(plugin)) {
cli::cli_abort('Use the {.fn attach} method to add plugins')
}
private$pluginList
},
#' @field root The location of the app. Setting this will remove the root value from requests (or decline them with `400` if the request does not match the root). E.g. the path of a request will be changed from `/demo/test` to `/test` if `root == '/demo'`
root = function(path) {
if (missing(path)) return(private$ROOT)
check_string(path)
path <- sub('/$', '', path)
if (path != '') path <- paste0('/', sub('^/+', '', path))
private$ROOT <- path
},
#' @field access_log_format A [glue][glue::glue] string defining how requests will be logged. For standard formats see [common_log_format] and [combined_log_format]. Defaults to the *Common Log Format*
access_log_format = function(format) {
if (missing(format)) return(private$ACCESS_LOG_FORMAT)
check_string(format)
private$ACCESS_LOG_FORMAT <- format
}
),
private = list(
# Data
HOST = '127.0.0.1',
PORT = 8080,
REFRESHRATE = 0.001,
REFRESHRATENB = 1,
TRIGGERDIR = NULL,
ROOT = '',
ACCESS_LOG_FORMAT = common_log_format,
running = FALSE,
nb_cycle = FALSE,
quitting = FALSE,
privateTriggers = c('start', 'resume', 'cycle-start', 'header',
'before-request', 'request', 'after-request',
'before-message', 'message', 'after-message',
'websocket-closed', 'send', 'cycle-end', 'end'),
data = NULL,
headers = list(),
handlers = NULL,
handlerMap = list(),
pluginList = list(),
websockets = NULL,
server = NULL,
client_id = NULL,
logger = list(logger_null()),
DELAY = NULL,
TIME = NULL,
ASYNC = NULL,
LOG_QUEUE = NULL,
# Methods
run = function(block = TRUE, resume = FALSE, showcase = FALSE, ..., silent = FALSE) {
check_bool(block)
check_bool(resume)
check_bool(showcase)
check_bool(silent)
if (!private$running) {
private$running <- TRUE
private$TIME$reset()
private$p_trigger('start', server = self, ...)
if (resume) {
private$p_trigger('resume', server = self, ...)
if (!silent) message('Fire restarted at ', self$host, ':', self$port, self$root)
self$log('resume', paste0(self$host, ':', self$port, self$root))
} else {
if (!silent) message('Fire started at ', self$host, ':', self$port, self$root)
self$log('start', paste0(self$host, ':', self$port, self$root))
}
if (block) {
on.exit({
private$running <- FALSE
private$p_trigger('end', server = self)
self$log('stop', paste0(self$host, ':', self$port, self$root))
})
private$run_blocking_server(showcase = showcase)
} else {
private$run_allowing_server(showcase = showcase)
}
} else {
self$log('warning', 'Server is already running and cannot be started')
}
},
run_blocking_server = function(showcase = FALSE) {
server <- startServer(
self$host,
self$port,
list(
call = private$request_logic,
onHeaders = private$header_logic,
onWSOpen = private$websocket_logic
)
)
on.exit(stopServer(server))
if (showcase) {
private$open_browser()
}
while (TRUE) {
private$p_trigger('cycle-start', server = self)
service()
private$external_triggers()
private$safe_call(private$DELAY$eval(server = self))
private$safe_call(private$TIME$eval(server = self))
private$safe_call(private$ASYNC$eval(server = self))
tri(private$LOG_QUEUE$eval(server = self))
private$p_trigger('cycle-end', server = self)
if (private$quitting) {
private$quitting <- FALSE
break
}
Sys.sleep(self$refresh_rate)
}
},
run_allowing_server = function(showcase = FALSE) {
private$server <- startDaemonizedServer(
self$host,
self$port,
list(
call = private$request_logic,
onHeaders = private$header_logic,
onWSOpen = private$websocket_logic
)
)
if (showcase) {
private$open_browser()
}
private$allowing_cycle()
},
allowing_cycle = function() {
if (private$running) {
private$nb_cycle <- TRUE # To hinder stopDeamonizedServer from crashing session
private$p_trigger('cycle-start', server = self)
private$external_triggers()
private$safe_call(private$DELAY$eval(server = self))
private$safe_call(private$TIME$eval(server = self))
private$safe_call(private$ASYNC$eval(server = self))
tri(private$LOG_QUEUE$eval(server = self))
private$p_trigger('cycle-end', server = self)
private$nb_cycle <- FALSE
later(function() {
private$allowing_cycle()
}, private$REFRESHRATENB)
}
},
mount_request = function(req) {
if (req$SCRIPT_NAME != self$root && !grepl(paste0('^', self$root, '(/|$)'), req$PATH_INFO)) {
cli::cli_abort('URL ({req$PATH_INFO}) not matching mount point ({self$root})')
}
req$SCRIPT_NAME <- self$root
req$PATH_INFO <- sub(paste0('^', self$root, ''), '', req$PATH_INFO)
req
},
request_logic = function(req) {
start_time <- Sys.time()
request <- tri(private$mount_request(req))
if (is.error_cond(request)) {
req <- Request$new(req)
id <- private$client_id(req)
response <- req$respond()
response$status_with_text(400L)
self$log('error', conditionMessage(request), req)
} else {
req <- Request$new(request)
id <- private$client_id(req)
args <- unlist(
unname(
private$p_trigger('before-request', server = self, id = id,
request = req)
),
recursive = FALSE
)
private$p_trigger('request', server = self, id = id, request = req, arg_list = args)
response <- req$respond()
for (i in names(private$headers)) response$set_header(i, private$headers[[i]])
response <- response$as_list()
private$p_trigger('after-request', server = self, id = id, request = req)
}
end_time <- Sys.time()
self$log('request', glue_log(
list(start_time = start_time, end_time = end_time, request = req, response = req$response, id = id),
self$access_log_format
), req)
response
},
header_logic = function(req) {
start_time <- Sys.time()
request <- tri(private$mount_request(req))
if (is.error_cond(request)) {
req <- Request$new(req)
id <- private$client_id(req)
response <- req$respond()
response$status_with_text(400L)
self$log('error', conditionMessage(request), req)
} else {
req <- Request$new(request)
id <- private$client_id(req)
response <- private$p_trigger('header', server = self, id = id, request = req)
response <- if (length(response) == 0) {
NULL
} else {
continue <- tail(response, 1)[[1]]
check_bool(continue)
if (continue) {
NULL
} else {
self$log('request', 'denied after header', req)
req$respond()$as_list()
}
}
}
if (!is.null(response)) {
end_time <- Sys.time()
self$log('request', glue_log(
list(start_time = start_time, end_time = end_time, request = req, response = req$response, id = id),
self$access_log_format
), req)
}
response
},
websocket_logic = function(ws) {
request <- tri(private$mount_request(ws$request))
if (is.error_cond(request)) {
self$log('error', conditionMessage(request))
ws$close()
return()
} else {
req <- Request$new(request)
}
id <- private$client_id(req)
assign(id, ws, envir = private$websockets)
self$log('websocket', paste0('connection established to ', id), req)
ws$onMessage(private$message_logic(id, req))
ws$onClose(private$close_ws_logic(id, req))
},
message_logic = function(id, request) {
function(binary, msg) {
start <- Sys.time()
args <- unlist(
unname(
private$p_trigger('before-message', server = self,
id = id, binary = binary,
message = msg, request = request)
),
recursive = FALSE
)
if (is.null(args)) args <- structure(list(), names = character())
if ('binary' %in% names(args)) binary <- args$binary
if ('message' %in% names(args)) msg <- args$message
args <- modifyList(args, list(binary = NULL, message = NULL))
private$p_trigger('message', server = self, id = id, binary = binary, message = msg, request = request, arg_list = args)
private$p_trigger('after-message', server = self, id = id, binary = binary, message = msg, request = request)
self$log('websocket', paste0('from ', id, ' processed in ', format(Sys.time() - start, digits = 3)), request, message = msg)
}
},
close_ws_logic = function(id, request) {
function() {
private$p_trigger('websocket-closed', server = self, id = id, request = request)
self$log('websocket', paste0('connection to ', id, ' closed from the client'), request)
}
},
add_handler = function(event, handler, pos, id) {
if (is.null(private$handlers[[event]])) {
private$handlers[[event]] <- HandlerStack$new()
}
private$handlers[[event]]$add(handler, id, pos)
},
remove_handler = function(id) {
event <- private$handlerMap[[id]]
private$handlers[[event]]$remove(id)
},
add_plugin = function(plugin, name) {
private$pluginList[[name]] <- plugin
},
p_trigger = function(event, ...) {
if (!is.null(private$handlers[[event]])) {
res <- private$safe_call(private$handlers[[event]]$dispatch(...))
for (val in res) if (is.error_cond(val)) self$log('error', paste0(conditionMessage(val), ' from ', deparse(conditionCall(val), nlines = 1)))
} else {
res <- setNames(list(), character())
}
res
},
external_triggers = function() {
if (is.null(private$TRIGGERDIR)) return()
triggerFiles <- list.files(private$TRIGGERDIR, pattern = '*.rds', ignore.case = TRUE, full.names = TRUE)
while (length(triggerFiles) > 0) {
nextFile <- order(file.info(triggerFiles)$ctime)[1]
event <- sub('\\.rds$', '', basename(triggerFiles[nextFile]), ignore.case = TRUE)
args <- readRDS(triggerFiles[nextFile])
unlink(triggerFiles[nextFile])
if (!is.list(args)) {
self$log('warning', 'External triggers must be an rds file containing a list')
} else {
args$event <- event
args$server <- self
do.call(private$p_trigger, args)
}
triggerFiles <- list.files(private$TRIGGERDIR, pattern = '*.rds', ignore.case = TRUE, full.names = TRUE)
}
},
safe_call = function(expr) {
withCallingHandlers(
tryCatch(expr, error = function(e) {
self$log('error', paste0(conditionMessage(e), ' from ', deparse(conditionCall(e), nlines = 1)))
}),
warning = function(w) {
self$log('warning', paste0(conditionMessage(w), ' from ', deparse(conditionCall(w), nlines = 1)))
invokeRestart('muffleWarning')
},
message = function(m) {
self$log('message', paste0(conditionMessage(m), ' from ', deparse(conditionCall(m), nlines = 1)))
invokeRestart('muffleMessage')
}
)
},
send_ws = function(message, id) {
if (!is.raw(message)) {
check_string(message)
}
if (missing(id) || is.null(id)) {
id <- ls(envir = private$websockets)
} else {
id <- intersect(id, ls(envir = private$websockets))
}
if (length(id) == 0) return(NULL)
for (i in id) {
private$websockets[[i]]$send(message)
}
self$log('websocket', paste0('send to ', paste(id, collapse = ', ')))
},
close_ws = function(id) {
ws <- private$websockets[[id]]
if (!is.null(ws)) {
try(ws$close(), silent = TRUE)
rm(list = id, envir = private$websockets)
self$log('websocket', paste0('connection to ', id, ' closed from the server'))
}
},
open_browser = function() {
url <- paste0('http://', private$HOST, ':', private$PORT, '/')
browseURL(url)
}
)
)
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R Package Documentation
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#' @include aaa.R
#' @include HandlerStack.R
#' @include loggers.R
NULL
#' Generate a New App Object
#'
#' @description
#' The Fire generator creates a new `Fire`-object, which is the class containing
#' all the app logic. The class is based on the [R6][R6::R6Class] OO-system and
#' is thus reference-based with methods and data attached to each object, in
#' contrast to the more well known S3 and S4 systems. A `fiery` server is event
#' driven, which means that it is build up and manipulated by adding event
#' handlers and triggering events. To learn more about the `fiery` event model,
#' read the [event vignette](https://fiery.data-imaginist.com/articles/events.html).
#' `fiery` servers can be modified directly or by attaching plugins. As with
#' events, [plugins has its own vignette](https://fiery.data-imaginist.com/articles/plugins.html).
#'
#' ## Initialization
#' A new 'Fire'-object is initialized using the `new()` method on the generator:
#'
#' \tabular{l}{
#' `app <- Fire$new(host = '127.0.0.1', port = 8080L)`
#' }
#'
#' ## Copying
#'
#' As `Fire` objects are using reference semantics new copies of an app cannot
#' be made simply be assigning it to a new variable. If a true copy of a `Fire`
#' object is desired, use the `clone()` method.
#'
#' @importFrom R6 R6Class
#' @importFrom httpuv startServer service startDaemonizedServer stopDaemonizedServer stopServer
#' @importFrom uuid UUIDgenerate
#' @importFrom utils browseURL
#' @importFrom later later
#' @importFrom stats setNames
#' @importFrom reqres Request
#' @importFrom stringi stri_pad_left
#'
#' @export
#'
#' @examples
#' # Create a New App
#' app <- Fire$new(port = 4689)
#'
#' # Setup the data every time it starts
#' app$on('start', function(server, ...) {
#' server$set_data('visits', 0)
#' server$set_data('cycles', 0)
#' })
#'
#' # Count the number of cycles
#' app$on('cycle-start', function(server, ...) {
#' server$set_data('cycles', server$get_data('cycles') + 1)
#' })
#'
#' # Count the number of requests
#' app$on('before-request', function(server, ...) {
#' server$set_data('visits', server$get_data('visits') + 1)
#' })
#'
#' # Handle requests
#' app$on('request', function(server, ...) {
#' list(
#' status = 200L,
#' headers = list('Content-Type' = 'text/html'),
#' body = paste('This is indeed a test. You are number', server$get_data('visits'))
#' )
#' })
#'
#' # Show number of requests in the console
#' app$on('after-request', function(server, ...) {
#' message(server$get_data('visits'))
#' flush.console()
#' })
#'
#' # Terminate the server after 300 cycles
#' app$on('cycle-end', function(server, ...) {
#' if (server$get_data('cycles') > 300) {
#' message('Ending...')
#' flush.console()
#' server$extinguish()
#' }
#' })
#'
#' # Be polite
#' app$on('end', function(server) {
#' message('Goodbye')
#' flush.console()
#' })
#'
#' \dontrun{
#' app$ignite(showcase = TRUE)
#' }
#'
Fire <- R6Class('Fire',
public = list(
# Methods
#' @description Create a new `Fire` app
#' @param host A string overriding the default host
#' @param port An port number overriding the default port
#' @return A `Fire` object
initialize = function(host = '127.0.0.1', port = 8080) {
self$host <- host
self$port <- port
private$data <- new.env(parent = emptyenv())
private$handlers <- new.env(parent = emptyenv())
private$websockets <- new.env(parent = emptyenv())
private$client_id <- client_to_id
private$DELAY <- DelayStack$new(self)
private$TIME <- TimeStack$new(self)
private$ASYNC <- AsyncStack$new(self)
private$LOG_QUEUE <- DelayStack$new(self)
},
#' @description Human readable description of the app
#' @param ... ignored
#' @return A character vector
format = function(...) {
text <- c(
'\U0001f525 A fiery webserver',
'\U0001f525 \U0001f4a5 \U0001f4a5 \U0001f4a5'
)
mat <- matrix(c('Running on', ': ', paste0(self$host, ':', self$port, self$root)), ncol = 3)
plugins <- names(private$pluginList)
if (is.null(plugins)) plugins <- 'none'
mat <- rbind(mat, c('Plugins attached', ': ', plugins[1]))
mat <- rbind(mat, matrix(c(rep(' ', (length(plugins) - 1)*2), plugins[-1]), ncol = 3))
handlers <- lapply(private$handlers, function(x) x$length())
if (length(handlers) == 0) {
mat <- rbind(mat, c('Event handlers added', ': ', 'none'))
} else {
mat <- rbind(mat, c('Event handlers added', '', ''))
order <- match(names(handlers), private$privateTriggers)
order[is.na(order)] <- seq_len(sum(is.na(order))) + max(order, na.rm = TRUE)
handlers <- handlers[order(order)]
mat <- rbind(mat, matrix(c(names(handlers), rep(': ', length(handlers)), as.character(unlist(handlers))), ncol = 3))
}
mat[, 1] <- stri_pad_left(mat[, 1], max(nchar(mat[,1])))
c(text, paste0('\U0001f525 ', apply(mat, 1, paste, collapse = '')))
},
#' @description Begin running the server. Will trigger the `start` event
#' @param block Should the console be blocked while running (alternative is to run in the background)
#' @param showcase Should the default browser open up at the server address
#' @param ... Arguments passed on to the `start` handler
#' @param silent Should startup messaging by silenced
ignite = function(block = TRUE, showcase = FALSE, ..., silent = FALSE) {
private$run(block = block, showcase = showcase, ..., silent = silent)
invisible(NULL)
},
#' @description Synonymous method to `ignite()`
#' @param ... passed on to `ignite()`
start = function(...) {
self$ignite(...)
},
#' @description Resume a session. This is equivalent to `ignite()` but will also trigger the `resume` event
#' @param ... passed on to `ignite()`
reignite = function(...) {
private$run(..., resume = TRUE)
invisible(NULL)
},
#' @description Synonymous method to `reignite()`
#' @param ... passed on to `ignite()`
resume = function(...) {
self$reignite(...)
},
#' @description Stop the server. Will trigger the `end` event
extinguish = function() {
if (private$running) {
if (!is.null(private$server)) {
if (private$nb_cycle) {
warning('Cannot stop server from within a non-blocking event cycle', call. = FALSE)
return(invisible(NULL))
} else {
private$running <- FALSE
private$p_trigger('end', server = self)
stopDaemonizedServer(private$server)
private$server <- NULL
self$log('stop', paste0(self$host, ':', self$port, self$root))
}
} else {
private$quitting <- TRUE
}
}
invisible(NULL)
},
#' @description Synonymous method to `extinguish()`
stop = function() {
self$extinguish()
},
#' @description Add a handler to an event. See the [*The event cycle in fiery* vignette](https://fiery.data-imaginist.com/articles/events.html) for more information.
#' @param event The name of the event that should trigger the handler
#' @param handler The handler function that should be triggered
#' @param pos The position in the handler stack to place it at. `NULL` will place it at the end.
#' @return A unique string identifying the handler
on = function(event, handler, pos = NULL) {
check_string(event)
check_function(handler)
handlerId <- UUIDgenerate()
private$handlerMap[[handlerId]] <- event
private$add_handler(event, handler, pos, handlerId)
invisible(handlerId)
},
#' @description Remove an event handler from the app.
#' @param handlerId The unique id identifying the handler
off = function(handlerId) {
check_string(handlerId)
private$remove_handler(handlerId)
private$handlerMap[[handlerId]] <- NULL
invisible(NULL)
},
#' @description Trigger an event in the app. This will cause any handler attached to the event to be called. See the [*The event cycle in fiery* vignette](https://fiery.data-imaginist.com/articles/events.html) for more information.
#' @param event The name of the event
#' @param ... Arguments passed on to the handlers
#' @return A named list containing the return values of all handlers attached to the event
trigger = function(event, ...) {
check_string(event)
if (event %in% private$privateTriggers) {
cli::cli_abort('{val {event}} and other protected events cannot be triggered manually')
} else {
private$p_trigger(event, server = self, ...)
}
},
#' @description Send a Websocket message to a client. Will trigger the `send` event.
#' @param message The message to send
#' @param id The id of the client to send to. If missing, the message will be send to all clients
send = function(message, id) {
private$send_ws(message, id)
private$p_trigger('send', server = self, id = id, message = message)
invisible(NULL)
},
#' @description Close a Websocket connection. Will trigger the `websocket-closed` event
#' @param id The id of the client to close the websocket connection to
close_ws_con = function(id) {
check_string(id)
ws <- private$websockets[[id]]
if (!is.null(ws)) {
private$close_ws(id)
}
},
#' @description Attach a plugin to the app. See the [*Creating and using fiery plugins* vignette](https://fiery.data-imaginist.com/articles/plugins.html) for more information
#' @param plugin The plugin to attach
#' @param ... Arguments to pass into the plugins `on_attach()` method
#' @param force If the plugin has already been attached an error is thrown, unless `force = TRUE` which tells the app to reattach it
attach = function(plugin, ..., force = FALSE) {
name <- plugin$name
check_string(name, arg = 'plugin$name')
if (!force && self$has_plugin(name)) {
cli::cli_abort(c(
'The {.arg {name}} plugin is already loaded.',
i = 'Use {.code force = TRUE} to reapply it.'
))
}
requires <- plugin$require
if (!is.null(requires)) {
check_character(requires)
exists <- vapply(requires, self$has_plugin, logical(1))
if (!all(exists)) {
cli::cli_abort('The {.arg {name}} plugin requires the following {cli::qty(requires[!exists])} plugin{?s}: {requires[!exists]}')
}
}
try_fetch(
plugin$on_attach(self, ...),
error = function(cnd) {
cli::cli_abort('The {.arg {name}} plugin failed to attach to the app', parent = cnd)
}
)
private$add_plugin(plugin, name)
invisible(NULL)
},
#' @description Check if the app has a plugin attached
#' @param name The name of the plugin
#' @return A boolean indicating if the given plugin is already attached
has_plugin = function(name) {
name %in% names(private$pluginList)
},
#' @description Add a global http header that will be applied to all responses
#' @param name The name of the header
#' @param value The value of the header. Use `NULL` to remove the global header
header = function(name, value) {
check_string(name)
if (missing(value)) return(private$headers[[name]])
check_string(value, allow_null = TRUE)
private$headers[[name]] <- value
invisible(NULL)
},
#' @description Add data to the global data store
#' @param name The name identifying the data
#' @param value The data to add
set_data = function(name, value) {
check_string(name)
assign(name, value, envir = private$data)
invisible(NULL)
},
#' @description Retrieve data from the global data store
#' @param name The name identifying the data
#' @return The data requested. Returns `NULL` if the store does not contain the requested data
get_data = function(name) {
check_string(name)
private$data[[name]]
},
#' @description Remove data from the global data store
#' @param name The name identifying the data to be removed
remove_data = function(name) {
check_string(name)
rm(list = name, envir = private$data)
invisible(NULL)
},
#' @description Add a timed evaluation that will be evaluated after the given number of seconds. See the [*Delaying code execution in Fiery* vignette](https://fiery.data-imaginist.com/articles/delayed.html) for more information
#' @param expr The expression to evaluate when the time has passed
#' @param then A handler to call once `expr` has been evaluated
#' @param after The time in second to wait before evaluating `expr`
#' @param loop Should `expr` be called repeatedly with the interval given by `after`
#' @return A unique id identifying the handler
time = function(expr, then, after, loop = FALSE) {
private$TIME$add(substitute(expr), then, after, loop, substituted = TRUE)
},
#' @description Remove a timed evaluation
#' @param id The unique id identifying the handler
remove_time = function(id) {
private$TIME$remove(id)
},
#' @description Add a delayed evaluation to be evaluated immediately at the end of the loop cycle. See the [*Delaying code execution in Fiery* vignette](https://fiery.data-imaginist.com/articles/delayed.html) for more information
#' @param expr The expression to evaluate at the end of the cycle
#' @param then A handler to call once `expr` has been evaluated
#' @return A unique id identifying the handler
delay = function(expr, then) {
private$DELAY$add(substitute(expr), then, substituted = TRUE)
},
#' @description Remove a delayed evaluation
#' @param id The unique id identifying the handler
remove_delay = function(id) {
private$DELAY$remove(id)
},
#' @description Add an asynchronous evaluation to be evaluated in another process without blocking the server. See the [*Delaying code execution in Fiery* vignette](https://fiery.data-imaginist.com/articles/delayed.html) for more information
#' @param expr The expression to evaluate at the end of the cycle
#' @param then A handler to call once `expr` has been evaluated
#' @return A unique id identifying the handler
async = function(expr, then) {
private$ASYNC$add(substitute(expr), then, substituted = TRUE)
},
#' @description Remove an async evaluation
#' @param id The unique id identifying the handler
remove_async = function(id) {
private$ASYNC$remove(id)
},
#' @description Sets the function that converts an HTTP request into a specific client id
#' @param converter A function with the argument `request`
set_client_id_converter = function(converter) {
check_args(converter, 'request')
private$client_id <- converter
invisible(NULL)
},
#' @description Sets the logging function to use
#' @param logger A function with the arguments `event`, `message`, `request`, and `...`
set_logger = function(logger) {
check_function(logger)
check_args(logger, c('event', 'message', 'request', '...'))
private$logger <- list(logger)
invisible(NULL)
},
#' @description Log a message with the logger attached to the app. See [loggers] for build in functionality
#' @param event The event associated with the message
#' @param message The message to log
#' @param request The `Request` object associated with the message, if any.
#' @param ... Additional arguments passed on to the logger.
log = function(event, message, request = NULL, ...) {
time <- Sys.time()
force(message)
if (private$running) {
private$LOG_QUEUE$add(NULL, function(...) private$logger[[1]](event, message, request, time, ...))
} else {
private$logger[[1]](event, message, request, time, ...)
}
invisible(NULL)
},
#' @description Test if an app is running
is_running = function() {
private$running
},
#' @description Send a request directly to the request logic of a non-running app. Only intended for testing the request logic
#' @param request The request to send
test_request = function(request) {
private$request_logic(request)
},
#' @description Send a request directly to the header logic of a non-running app. Only intended for testing the request logic
#' @param request The request to send
test_header = function(request) {
private$header_logic(request)
},
#' @description Send a message directly **to** the message logic of a non-running app. Only intended for testing the websocket logic
#' @param request The request to use to establish the connection
#' @param binary Is the message send in binary or character format
#' @param message The message to send. If `binary = FALSE` a character vector, if `binary = TRUE` a raw vector
#' @param withClose Should the websocket connection be closed at the end by the client
test_message = function(request, binary, message, withClose = TRUE) {
id <- private$client_id(request)
message_fun <- private$message_logic(id, request)
message_fun(binary, message)
if (withClose) {
close_fun <- private$close_ws_logic(id, request)
close_fun()
}
},
#' @description Send a message directly **from** a non-running app. Only intended for testing the websocket logic
#' @param request The request to use to establish the connection
#' @param message The message to send from the app
#' @param close Should the websocket connection be closed at the end by the server
test_websocket = function(request, message, close = TRUE) {
ws <- list(
request = request,
onMessage = function(func) {},
onClose = function(func) {},
send = function(message) {message(message)},
close = function() {message('closing')}
)
private$websocket_logic(ws)
self$send(message, private$client_id(request))
if (close) private$close_ws(private$client_id(request))
}
),
active = list(
#' @field host A string giving a valid IPv4 address owned by the server, or `'0.0.0.0'` to listen on all addresses. The default is `'127.0.0.1'`
host = function(address) {
if (missing(address)) return(private$HOST)
check_string(address)
private$HOST <- address
},
#' @field port An integer giving the port number the server should listen on (defaults to `8080L`)
port = function(n) {
if (missing(n)) return(private$PORT)
check_number_whole(n, min = 1)
private$PORT <- n
},
#' @field refresh_rate The interval in seconds between run cycles when running a blocking server (defaults to `0.001`)
refresh_rate = function(rate) {
if (missing(rate)) return(private$REFRESHRATE)
check_number_decimal(rate)
private$REFRESHRATE <- rate
},
#' @field refresh_rate_nb The interval in seconds between run cycles when running a non-blocking server (defaults to `1`)
refresh_rate_nb = function(rate) {
if (missing(rate)) return(private$REFRESHRATENB)
check_number_decimal(rate)
private$REFRESHRATENB <- rate
},
#' @field trigger_dir A valid folder where trigger files can be put when running a blocking server (defaults to `NULL`). See the [*The event cycle in fiery* vignette](https://fiery.data-imaginist.com/articles/events.html) for more information.
trigger_dir = function(dir) {
if (missing(dir)) return(private$TRIGGERDIR)
check_dir(dir, allow_null = TRUE)
private$TRIGGERDIR <- dir
},
#' @field plugins A named list of the already attached plugins. **Read Only** - can only be modified using the `attach()` method.
plugins = function(plugin) {
if (!missing(plugin)) {
cli::cli_abort('Use the {.fn attach} method to add plugins')
}
private$pluginList
},
#' @field root The location of the app. Setting this will remove the root value from requests (or decline them with `400` if the request does not match the root). E.g. the path of a request will be changed from `/demo/test` to `/test` if `root == '/demo'`
root = function(path) {
if (missing(path)) return(private$ROOT)
check_string(path)
path <- sub('/$', '', path)
if (path != '') path <- paste0('/', sub('^/+', '', path))
private$ROOT <- path
},
#' @field access_log_format A [glue][glue::glue] string defining how requests will be logged. For standard formats see [common_log_format] and [combined_log_format]. Defaults to the *Common Log Format*
access_log_format = function(format) {
if (missing(format)) return(private$ACCESS_LOG_FORMAT)
check_string(format)
private$ACCESS_LOG_FORMAT <- format
}
),
private = list(
# Data
HOST = '127.0.0.1',
PORT = 8080,
REFRESHRATE = 0.001,
REFRESHRATENB = 1,
TRIGGERDIR = NULL,
ROOT = '',
ACCESS_LOG_FORMAT = common_log_format,
running = FALSE,
nb_cycle = FALSE,
quitting = FALSE,
privateTriggers = c('start', 'resume', 'cycle-start', 'header',
'before-request', 'request', 'after-request',
'before-message', 'message', 'after-message',
'websocket-closed', 'send', 'cycle-end', 'end'),
data = NULL,
headers = list(),
handlers = NULL,
handlerMap = list(),
pluginList = list(),
websockets = NULL,
server = NULL,
client_id = NULL,
logger = list(logger_null()),
DELAY = NULL,
TIME = NULL,
ASYNC = NULL,
LOG_QUEUE = NULL,
# Methods
run = function(block = TRUE, resume = FALSE, showcase = FALSE, ..., silent = FALSE) {
check_bool(block)
check_bool(resume)
check_bool(showcase)
check_bool(silent)
if (!private$running) {
private$running <- TRUE
private$TIME$reset()
private$p_trigger('start', server = self, ...)
if (resume) {
private$p_trigger('resume', server = self, ...)
if (!silent) message('Fire restarted at ', self$host, ':', self$port, self$root)
self$log('resume', paste0(self$host, ':', self$port, self$root))
} else {
if (!silent) message('Fire started at ', self$host, ':', self$port, self$root)
self$log('start', paste0(self$host, ':', self$port, self$root))
}
if (block) {
on.exit({
private$running <- FALSE
private$p_trigger('end', server = self)
self$log('stop', paste0(self$host, ':', self$port, self$root))
})
private$run_blocking_server(showcase = showcase)
} else {
private$run_allowing_server(showcase = showcase)
}
} else {
self$log('warning', 'Server is already running and cannot be started')
}
},
run_blocking_server = function(showcase = FALSE) {
server <- startServer(
self$host,
self$port,
list(
call = private$request_logic,
onHeaders = private$header_logic,
onWSOpen = private$websocket_logic
)
)
on.exit(stopServer(server))
if (showcase) {
private$open_browser()
}
while (TRUE) {
private$p_trigger('cycle-start', server = self)
service()
private$external_triggers()
private$safe_call(private$DELAY$eval(server = self))
private$safe_call(private$TIME$eval(server = self))
private$safe_call(private$ASYNC$eval(server = self))
tri(private$LOG_QUEUE$eval(server = self))
private$p_trigger('cycle-end', server = self)
if (private$quitting) {
private$quitting <- FALSE
break
}
Sys.sleep(self$refresh_rate)
}
},
run_allowing_server = function(showcase = FALSE) {
private$server <- startDaemonizedServer(
self$host,
self$port,
list(
call = private$request_logic,
onHeaders = private$header_logic,
onWSOpen = private$websocket_logic
)
)
if (showcase) {
private$open_browser()
}
private$allowing_cycle()
},
allowing_cycle = function() {
if (private$running) {
private$nb_cycle <- TRUE # To hinder stopDeamonizedServer from crashing session
private$p_trigger('cycle-start', server = self)
private$external_triggers()
private$safe_call(private$DELAY$eval(server = self))
private$safe_call(private$TIME$eval(server = self))
private$safe_call(private$ASYNC$eval(server = self))
tri(private$LOG_QUEUE$eval(server = self))
private$p_trigger('cycle-end', server = self)
private$nb_cycle <- FALSE
later(function() {
private$allowing_cycle()
}, private$REFRESHRATENB)
}
},
mount_request = function(req) {
if (req$SCRIPT_NAME != self$root && !grepl(paste0('^', self$root, '(/|$)'), req$PATH_INFO)) {
cli::cli_abort('URL ({req$PATH_INFO}) not matching mount point ({self$root})')
}
req$SCRIPT_NAME <- self$root
req$PATH_INFO <- sub(paste0('^', self$root, ''), '', req$PATH_INFO)
req
},
request_logic = function(req) {
start_time <- Sys.time()
request <- tri(private$mount_request(req))
if (is.error_cond(request)) {
req <- Request$new(req)
id <- private$client_id(req)
response <- req$respond()
response$status_with_text(400L)
self$log('error', conditionMessage(request), req)
} else {
req <- Request$new(request)
id <- private$client_id(req)
args <- unlist(
unname(
private$p_trigger('before-request', server = self, id = id,
request = req)
),
recursive = FALSE
)
private$p_trigger('request', server = self, id = id, request = req, arg_list = args)
response <- req$respond()
for (i in names(private$headers)) response$set_header(i, private$headers[[i]])
response <- response$as_list()
private$p_trigger('after-request', server = self, id = id, request = req)
}
end_time <- Sys.time()
self$log('request', glue_log(
list(start_time = start_time, end_time = end_time, request = req, response = req$response, id = id),
self$access_log_format
), req)
response
},
header_logic = function(req) {
start_time <- Sys.time()
request <- tri(private$mount_request(req))
if (is.error_cond(request)) {
req <- Request$new(req)
id <- private$client_id(req)
response <- req$respond()
response$status_with_text(400L)
self$log('error', conditionMessage(request), req)
} else {
req <- Request$new(request)
id <- private$client_id(req)
response <- private$p_trigger('header', server = self, id = id, request = req)
response <- if (length(response) == 0) {
NULL
} else {
continue <- tail(response, 1)[[1]]
check_bool(continue)
if (continue) {
NULL
} else {
self$log('request', 'denied after header', req)
req$respond()$as_list()
}
}
}
if (!is.null(response)) {
end_time <- Sys.time()
self$log('request', glue_log(
list(start_time = start_time, end_time = end_time, request = req, response = req$response, id = id),
self$access_log_format
), req)
}
response
},
websocket_logic = function(ws) {
request <- tri(private$mount_request(ws$request))
if (is.error_cond(request)) {
self$log('error', conditionMessage(request))
ws$close()
return()
} else {
req <- Request$new(request)
}
id <- private$client_id(req)
assign(id, ws, envir = private$websockets)
self$log('websocket', paste0('connection established to ', id), req)
ws$onMessage(private$message_logic(id, req))
ws$onClose(private$close_ws_logic(id, req))
},
message_logic = function(id, request) {
function(binary, msg) {
start <- Sys.time()
args <- unlist(
unname(
private$p_trigger('before-message', server = self,
id = id, binary = binary,
message = msg, request = request)
),
recursive = FALSE
)
if (is.null(args)) args <- structure(list(), names = character())
if ('binary' %in% names(args)) binary <- args$binary
if ('message' %in% names(args)) msg <- args$message
args <- modifyList(args, list(binary = NULL, message = NULL))
private$p_trigger('message', server = self, id = id, binary = binary, message = msg, request = request, arg_list = args)
private$p_trigger('after-message', server = self, id = id, binary = binary, message = msg, request = request)
self$log('websocket', paste0('from ', id, ' processed in ', format(Sys.time() - start, digits = 3)), request, message = msg)
}
},
close_ws_logic = function(id, request) {
function() {
private$p_trigger('websocket-closed', server = self, id = id, request = request)
self$log('websocket', paste0('connection to ', id, ' closed from the client'), request)
}
},
add_handler = function(event, handler, pos, id) {
if (is.null(private$handlers[[event]])) {
private$handlers[[event]] <- HandlerStack$new()
}
private$handlers[[event]]$add(handler, id, pos)
},
remove_handler = function(id) {
event <- private$handlerMap[[id]]
private$handlers[[event]]$remove(id)
},
add_plugin = function(plugin, name) {
private$pluginList[[name]] <- plugin
},
p_trigger = function(event, ...) {
if (!is.null(private$handlers[[event]])) {
res <- private$safe_call(private$handlers[[event]]$dispatch(...))
for (val in res) if (is.error_cond(val)) self$log('error', paste0(conditionMessage(val), ' from ', deparse(conditionCall(val), nlines = 1)))
} else {
res <- setNames(list(), character())
}
res
},
external_triggers = function() {
if (is.null(private$TRIGGERDIR)) return()
triggerFiles <- list.files(private$TRIGGERDIR, pattern = '*.rds', ignore.case = TRUE, full.names = TRUE)
while (length(triggerFiles) > 0) {
nextFile <- order(file.info(triggerFiles)$ctime)[1]
event <- sub('\\.rds$', '', basename(triggerFiles[nextFile]), ignore.case = TRUE)
args <- readRDS(triggerFiles[nextFile])
unlink(triggerFiles[nextFile])
if (!is.list(args)) {
self$log('warning', 'External triggers must be an rds file containing a list')
} else {
args$event <- event
args$server <- self
do.call(private$p_trigger, args)
}
triggerFiles <- list.files(private$TRIGGERDIR, pattern = '*.rds', ignore.case = TRUE, full.names = TRUE)
}
},
safe_call = function(expr) {
withCallingHandlers(
tryCatch(expr, error = function(e) {
self$log('error', paste0(conditionMessage(e), ' from ', deparse(conditionCall(e), nlines = 1)))
}),
warning = function(w) {
self$log('warning', paste0(conditionMessage(w), ' from ', deparse(conditionCall(w), nlines = 1)))
invokeRestart('muffleWarning')
},
message = function(m) {
self$log('message', paste0(conditionMessage(m), ' from ', deparse(conditionCall(m), nlines = 1)))
invokeRestart('muffleMessage')
}
)
},
send_ws = function(message, id) {
if (!is.raw(message)) {
check_string(message)
}
if (missing(id) || is.null(id)) {
id <- ls(envir = private$websockets)
} else {
id <- intersect(id, ls(envir = private$websockets))
}
if (length(id) == 0) return(NULL)
for (i in id) {
private$websockets[[i]]$send(message)
}
self$log('websocket', paste0('send to ', paste(id, collapse = ', ')))
},
close_ws = function(id) {
ws <- private$websockets[[id]]
if (!is.null(ws)) {
try(ws$close(), silent = TRUE)
rm(list = id, envir = private$websockets)
self$log('websocket', paste0('connection to ', id, ' closed from the server'))
}
},
open_browser = function() {
url <- paste0('http://', private$HOST, ':', private$PORT, '/')
browseURL(url)
}
)
)
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