The Fire generator creates a new Fire-object, which is the class containing
all the app logic. The class is based on the R6 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.
fiery servers can be modified directly or by attaching plugins. As with
events, plugins has its own vignette.
A new 'Fire'-object is initialized using the new() method on the generator:
app <- Fire$new(host = '127.0.0.1', port = 8080L) |
As Fire objects are using reference semantics new copies of an app cannot
be made simply be assigning it to a new variable. If a true copy of a Fire
object is desired, use the clone() method.
hostA string giving a valid IPv4 address owned by the server, or '0.0.0.0' to listen on all addresses. The default is '127.0.0.1'
portAn integer giving the port number the server should listen on (defaults to 8080L)
refresh_rateThe interval in seconds between run cycles when running a blocking server (defaults to 0.001)
refresh_rate_nbThe interval in seconds between run cycles when running a non-blocking server (defaults to 1)
trigger_dirA valid folder where trigger files can be put when running a blocking server (defaults to NULL). See the The event cycle in fiery vignette for more information.
pluginsA named list of the already attached plugins. Read Only - can only be modified using the attach() method.
rootThe location of the app. Setting this will remove the root value from requests (or decline them with 400 if the request does not match the root). E.g. the path of a request will be changed from /demo/test to /test if root == '/demo'
access_log_formatA glue string defining how requests will be logged. For standard formats see common_log_format and combined_log_format. Defaults to the Common Log Format
new()Create a new Fire app
Fire$new(host = "127.0.0.1", port = 8080)hostA string overriding the default host
portAn port number overriding the default port
A Fire object
...ignored
A character vector
ignite()Begin running the server. Will trigger the start event
Fire$ignite(block = TRUE, showcase = FALSE, ..., silent = FALSE)blockShould the console be blocked while running (alternative is to run in the background)
showcaseShould the default browser open up at the server address
...Arguments passed on to the start handler
silentShould startup messaging by silenced
...passed on to ignite()
reignite()Resume a session. This is equivalent to ignite() but will also trigger the resume event
Fire$reignite(...)...passed on to ignite()
resume()Synonymous method to reignite()
Fire$resume(...)...passed on to ignite()
extinguish()Stop the server. Will trigger the end event
Fire$extinguish()
on()Add a handler to an event. See the The event cycle in fiery vignette for more information.
Fire$on(event, handler, pos = NULL)eventThe name of the event that should trigger the handler
handlerThe handler function that should be triggered
posThe position in the handler stack to place it at. NULL will place it at the end.
A unique string identifying the handler
off()Remove an event handler from the app.
Fire$off(handlerId)handlerIdThe unique id identifying the handler
trigger()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 for more information.
Fire$trigger(event, ...)eventThe name of the event
...Arguments passed on to the handlers
A named list containing the return values of all handlers attached to the event
send()Send a Websocket message to a client. Will trigger the send event.
Fire$send(message, id)messageThe message to send
idThe id of the client to send to. If missing, the message will be send to all clients
close_ws_con()Close a Websocket connection. Will trigger the websocket-closed event
Fire$close_ws_con(id)idThe id of the client to close the websocket connection to
attach()Attach a plugin to the app. See the Creating and using fiery plugins vignette for more information
Fire$attach(plugin, ..., force = FALSE)pluginThe plugin to attach
...Arguments to pass into the plugins on_attach() method
forceIf the plugin has already been attached an error is thrown, unless force = TRUE which tells the app to reattach it
has_plugin()Check if the app has a plugin attached
Fire$has_plugin(name)nameThe name of the plugin
A boolean indicating if the given plugin is already attached
header()Add a global http header that will be applied to all responses
Fire$header(name, value)nameThe name of the header
valueThe value of the header. Use NULL to remove the global header
set_data()Add data to the global data store
Fire$set_data(name, value)nameThe name identifying the data
valueThe data to add
get_data()Retrieve data from the global data store
Fire$get_data(name)nameThe name identifying the data
The data requested. Returns NULL if the store does not contain the requested data
remove_data()Remove data from the global data store
Fire$remove_data(name)nameThe name identifying the data to be removed
time()Add a timed evaluation that will be evaluated after the given number of seconds. See the Delaying code execution in Fiery vignette for more information
Fire$time(expr, then, after, loop = FALSE)exprThe expression to evaluate when the time has passed
thenA handler to call once expr has been evaluated
afterThe time in second to wait before evaluating expr
loopShould expr be called repeatedly with the interval given by after
A unique id identifying the handler
remove_time()Remove a timed evaluation
Fire$remove_time(id)idThe unique id identifying the handler
delay()Add a delayed evaluation to be evaluated immediately at the end of the loop cycle. See the Delaying code execution in Fiery vignette for more information
Fire$delay(expr, then)exprThe expression to evaluate at the end of the cycle
thenA handler to call once expr has been evaluated
A unique id identifying the handler
remove_delay()Remove a delayed evaluation
Fire$remove_delay(id)idThe unique id identifying the handler
async()Add an asynchronous evaluation to be evaluated in another process without blocking the server. See the Delaying code execution in Fiery vignette for more information
Fire$async(expr, then)exprThe expression to evaluate at the end of the cycle
thenA handler to call once expr has been evaluated
A unique id identifying the handler
remove_async()Remove an async evaluation
Fire$remove_async(id)idThe unique id identifying the handler
set_client_id_converter()Sets the function that converts an HTTP request into a specific client id
Fire$set_client_id_converter(converter)converterA function with the argument request
set_logger()Sets the logging function to use
Fire$set_logger(logger)loggerA function with the arguments event, message, request, and ...
log()Log a message with the logger attached to the app. See loggers for build in functionality
Fire$log(event, message, request = NULL, ...)eventThe event associated with the message
messageThe message to log
requestThe Request object associated with the message, if any.
...Additional arguments passed on to the logger.
is_running()Test if an app is running
Fire$is_running()
test_request()Send a request directly to the request logic of a non-running app. Only intended for testing the request logic
Fire$test_request(request)requestThe request to send
test_header()Send a request directly to the header logic of a non-running app. Only intended for testing the request logic
Fire$test_header(request)requestThe request to send
test_message()Send a message directly to the message logic of a non-running app. Only intended for testing the websocket logic
Fire$test_message(request, binary, message, withClose = TRUE)requestThe request to use to establish the connection
binaryIs the message send in binary or character format
messageThe message to send. If binary = FALSE a character vector, if binary = TRUE a raw vector
withCloseShould the websocket connection be closed at the end by the client
test_websocket()Send a message directly from a non-running app. Only intended for testing the websocket logic
Fire$test_websocket(request, message, close = TRUE)requestThe request to use to establish the connection
messageThe message to send from the app
closeShould the websocket connection be closed at the end by the server
clone()The objects of this class are cloneable with this method.
Fire$clone(deep = FALSE)deepWhether to make a deep clone.
# 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()
})
if (FALSE) {
app$ignite(showcase = TRUE)
}
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