Fire {fiery}R Documentation

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 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.

Initialization

A new 'Fire'-object is initialized using the new() method on the generator:

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.

Active bindings

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'

port

An integer giving the port number the server should listen on (defaults to 8080L)

refresh_rate

The interval in seconds between run cycles when running a blocking server (defaults to 0.001)

refresh_rate_nb

The interval in seconds between run cycles when running a non-blocking server (defaults to 1)

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 for more information.

plugins

A named list of the already attached plugins. Read Only - can only be modified using the attach() method.

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'

access_log_format

A 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

Methods

Public methods

Method new()

Create a new Fire app

Usage
Fire$new(host = "127.0.0.1", port = 8080)
Arguments
host

A string overriding the default host

port

An port number overriding the default port

Returns

A Fire object

Method format()

Human readable description of the app

Usage
Fire$format(...)
Arguments
...

ignored

Returns

A character vector

Method ignite()

Begin running the server. Will trigger the start event

Usage
Fire$ignite(block = TRUE, showcase = FALSE, ..., silent = FALSE)
Arguments
block

Should the console be blocked while running (alternative is to run in the background)

showcase

Should the default browser open up at the server address

...

Arguments passed on to the start handler

silent

Should startup messaging by silenced

Method start()

Synonymous method to ignite()

Usage
Fire$start(...)
Arguments
...

passed on to ignite()

Method reignite()

Resume a session. This is equivalent to ignite() but will also trigger the resume event

Usage
Fire$reignite(...)
Arguments
...

passed on to ignite()

Method resume()

Synonymous method to reignite()

Usage
Fire$resume(...)
Arguments
...

passed on to ignite()

Method extinguish()

Stop the server. Will trigger the end event

Usage
Fire$extinguish()

Method stop()

Synonymous method to extinguish()

Usage
Fire$stop()

Method on()

Add a handler to an event. See the The event cycle in fiery vignette for more information.

Usage
Fire$on(event, handler, pos = NULL)
Arguments
event

The name of the event that should trigger the handler

handler

The handler function that should be triggered

pos

The position in the handler stack to place it at. NULL will place it at the end.

Returns

A unique string identifying the handler

Method off()

Remove an event handler from the app.

Usage
Fire$off(handlerId)
Arguments
handlerId

The unique id identifying the handler

Method 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.

Usage
Fire$trigger(event, ...)
Arguments
event

The name of the event

...

Arguments passed on to the handlers

Returns

A named list containing the return values of all handlers attached to the event

Method send()

Send a Websocket message to a client. Will trigger the send event.

Usage
Fire$send(message, id)
Arguments
message

The message to send

id

The id of the client to send to. If missing, the message will be send to all clients

Method close_ws_con()

Close a Websocket connection. Will trigger the websocket-closed event

Usage
Fire$close_ws_con(id)
Arguments
id

The id of the client to close the websocket connection to

Method attach()

Attach a plugin to the app. See the Creating and using fiery plugins vignette for more information

Usage
Fire$attach(plugin, ..., force = FALSE)
Arguments
plugin

The plugin to attach

...

Arguments to pass into the plugins on_attach() method

force

If the plugin has already been attached an error is thrown, unless force = TRUE which tells the app to reattach it

Method has_plugin()

Check if the app has a plugin attached

Usage
Fire$has_plugin(name)
Arguments
name

The name of the plugin

Returns

A boolean indicating if the given plugin is already attached

Method header()

Add a global http header that will be applied to all responses

Usage
Fire$header(name, value)
Arguments
name

The name of the header

value

The value of the header. Use NULL to remove the global header

Method set_data()

Add data to the global data store

Usage
Fire$set_data(name, value)
Arguments
name

The name identifying the data

value

The data to add

Method get_data()

Retrieve data from the global data store

Usage
Fire$get_data(name)
Arguments
name

The name identifying the data

Returns

The data requested. Returns NULL if the store does not contain the requested data

Method remove_data()

Remove data from the global data store

Usage
Fire$remove_data(name)
Arguments
name

The name identifying the data to be removed

Method 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

Usage
Fire$time(expr, then, after, loop = FALSE)
Arguments
expr

The expression to evaluate when the time has passed

then

A handler to call once expr has been evaluated

after

The time in second to wait before evaluating expr

loop

Should expr be called repeatedly with the interval given by after

Returns

A unique id identifying the handler

Method remove_time()

Remove a timed evaluation

Usage
Fire$remove_time(id)
Arguments
id

The unique id identifying the handler

Method 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

Usage
Fire$delay(expr, then)
Arguments
expr

The expression to evaluate at the end of the cycle

then

A handler to call once expr has been evaluated

Returns

A unique id identifying the handler

Method remove_delay()

Remove a delayed evaluation

Usage
Fire$remove_delay(id)
Arguments
id

The unique id identifying the handler

Method 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

Usage
Fire$async(expr, then)
Arguments
expr

The expression to evaluate at the end of the cycle

then

A handler to call once expr has been evaluated

Returns

A unique id identifying the handler

Method remove_async()

Remove an async evaluation

Usage
Fire$remove_async(id)
Arguments
id

The unique id identifying the handler

Method set_client_id_converter()

Sets the function that converts an HTTP request into a specific client id

Usage
Fire$set_client_id_converter(converter)
Arguments
converter

A function with the argument request

Method set_logger()

Sets the logging function to use

Usage
Fire$set_logger(logger)
Arguments
logger

A function with the arguments event, message, request, and ...

Method log()

Log a message with the logger attached to the app. See loggers for build in functionality

Usage
Fire$log(event, message, request = NULL, ...)
Arguments
event

The event associated with the message

message

The message to log

request

The Request object associated with the message, if any.

...

Additional arguments passed on to the logger.

Method is_running()

Test if an app is running

Usage
Fire$is_running()

Method test_request()

Send a request directly to the request logic of a non-running app. Only intended for testing the request logic

Usage
Fire$test_request(request)
Arguments
request

The request to send

Method test_header()

Send a request directly to the header logic of a non-running app. Only intended for testing the request logic

Usage
Fire$test_header(request)
Arguments
request

The request to send

Method test_message()

Send a message directly to the message logic of a non-running app. Only intended for testing the websocket logic

Usage
Fire$test_message(request, binary, message, withClose = TRUE)
Arguments
request

The request to use to establish the connection

binary

Is the message send in binary or character format

message

The message to send. If binary = FALSE a character vector, if binary = TRUE a raw vector

withClose

Should the websocket connection be closed at the end by the client

Method test_websocket()

Send a message directly from a non-running app. Only intended for testing the websocket logic

Usage
Fire$test_websocket(request, message, close = TRUE)
Arguments
request

The request to use to establish the connection

message

The message to send from the app

close

Should the websocket connection be closed at the end by the server

Method clone()

The objects of this class are cloneable with this method.

Usage
Fire$clone(deep = FALSE)
Arguments
deep

Whether to make a deep clone.

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()
})

## Not run: 
app$ignite(showcase = TRUE)

## End(Not run)
[Package fiery version 1.2.1 Index]