App: Web Application
In tjpalanca/webtools: Web Server Tools
Description
Super class
Active bindings
Methods
Description
Overview
Web Application object based on fiery::Fire via Fire and
contains the following modifications:
Takes advantage of httpuv::staticPath() via Fire to serve,
assets which "happens entirely within the I/O thread, so doing so will not
block or be blocked by activity in the main R thread."
Incorporates the routr package for routing, instead of relying on the
user to create it separately.
Adds load testing, profiling, and benchmarking functionality for the app
itself and for individual routers.
Methods return the self object to allow method chaining.
Renames some methods to conform to some sort of prefixing structure for
better discovery.
Methods
-
Lifecycle (lifecycle_)
Lifecycle handlers handle starting, stopping, and other development
utilities for web applications.
-
Settings (set_)
set clients, headers, and other things that are globally applicable to
this application instance.
-
Data (data)
arbitrary data that can be set or retrieved from the object data store.
-
Handlers (handle_)
Handlers are functions that run on a specific event trigger.
-
Routers (route_)
create handlers for specific virtual paths.
-
Static Paths (static_)
create static paths for serving static files from disk.
-
Websockets (ws_)
WebSocket is a bi-directional communication protocol that is very useful
when you need to persistently poll or receive new information.
It's also useful to set the
ID with set_clients so that they can easily be identified.
-
Plugins (plugin_)
Fiery functionality allows you to add plugins. See
here for more
information on how to use plugins. The interface implemented is similar
except that we have access to the whole object not just to the contained
Fire object.
Details
Super class
webtools::Configurable -> App
Active bindings
pluginsread-only field for plugins attached
fireread-only field for the fire object
handlesread-only field for the handles attached
routersread-only field for the routers attached
staticsread-only field for the paths attached
dataalternative way of accessing application data
socketsread-only list of active websockets
eventshelp information
Methods
Public methods
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Inherited methods
Method new()
Create a new Application
Usage
App$new(
...,
host = "0.0.0.0",
port = 3838L,
root = "",
headers = NULL,
client_id_converter = function(request) { request$trust <- TRUE
return(request$ip) },
path_extractor = function(msg, bin) "/",
refresh_rate = 0.001,
refresh_rate_nb = 0.001,
trigger_dir = NULL,
access_log_format = common_log_format,
logger = if (interactive()) { logger_console() } else { logger_null() }
)
Arguments
...(Plugin)s to attach to this Application Instance
host(str) IP address; defaults to all addresses.
port(int) port number from 0 to 65535.
root(str) path at which fiery will serve requests
headers(lst) global header that will be set on all responses
client_id_converter(fun) function that converts a request into
a client ID
path_extractor(fun) function that converts a message to
a path on which to dispatch
refresh_rate(num) blocking refresh rate for run cycles
refresh_rate_nb(num) non-blocking refresh rate for run cycles
trigger_dir(path) directory in which you can save RDS files
of lists where the external-event trigger will be triggered with
the list as arguments. See
events.
access_log_format(str/fn) provider of the logging service.
logger(fn) logger for this application.
Method browse()
Browse to the App URL
Usage
App$browse()
Method finalize()
Finalizer
Usage
App$finalize()
Method lifecycle_start()
Start the application
Usage
App$lifecycle_start(..., block = FALSE, browse = FALSE, silent = FALSE)
Arguments
...(args) passed to the start or resume handler
block(flag) blocking server
browse(flag) open a browser after starting
silent(flag) do not log to console
Method lifecycle_stop()
Stop the application
Usage
App$lifecycle_stop()
Method lifecycle_is_running()
Checks if the app is still running
Usage
App$lifecycle_is_running()
Method set_client_id_converter()
Set client converter
Usage
App$set_client_id_converter(client_id_converter)
Arguments
client_id_converter(fun) takes request and returns client ID
Method set_path_extractor()
Set the path extractor
Usage
App$set_path_extractor(extractor)
Arguments
extractorfunction that takes the message and returns a path
Method set_headers()
Set the heaers to be sent with every response
Usage
App$set_headers(..., .list = NULL)
Arguments
...(arg) key-value pairs
.list(lst) provide the values as a list
Method set_logger()
Set the logger function
Usage
App$set_logger(logger)
Arguments
logger(fun) logger function; there are some presets:
-
logger_null() - only error, warning, message events
-
logger_console() - everything to console
-
logger_file() - everything to file
-
logger_switch() - file or console dependeing on need
Can also be any function that takes arguments: event, message,
request = NULL, time = Sys.time(), and ....
Method set_data()
set data inside the app object; list merge semantics
Usage
App$set_data(name, value)
Arguments
name(str) name of the data
value(arg) key value data
Method get_data()
get data inside the app object
Usage
App$get_data(name)
Arguments
name(str) name of the data
Method clear_data()
clear all data in side the app object
Usage
App$clear_data()
Method log()
Send an application log
Usage
App$log(event, message, request = NULL, ..., .envir = parent.frame())
Arguments
event(str) event attached
message(str) glue string
request(req) reqres::Request object
...(arg) extra arguments
.envir(env) calling environment
Method handle()
Attach a handler to an event
Usage
App$handle(event, name, handler, ..., position = NULL)
Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_find()
Find a handler to an event
Usage
App$handle_find(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method handle_remove()
Remove a handler
Usage
App$handle_remove(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method handle_lifecycle()
Lifecycle Handler
Triggered once per server invocation.
Return value is ignored.
Arguments
-
server - application itself
-
... - extra arguments
Events
-
start/resume - app is started, but not running; resume is when
app_start(resume = TRUE) is called.
-
end - when app is stopped using app_stop().
Usage
App$handle_lifecycle(
event = c("start", "resume", "end"),
name,
handler,
...,
position = NULL
)
Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_cycle()
Cycle Handler
Triggered for every event loop.
Return value is ignored.
Arguments
-
server - application
Events
-
start - beginning of the loop; pre-logging.
-
end - end of the loop; post-logging.
Usage
App$handle_cycle(
event = c("start", "end"),
name,
handler,
...,
position = NULL
)
Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_request()
Request Handler
Triggered by actual request made to the web server.
Arguments
-
server - application itself
-
id - client identifier
-
request - request itself
-
arg_list - for request event, the return value from the before
handler, if any.
-
response - for after event, the response object
Events
-
header - when HTTP headers are received; return FALSE to
short-circuit; return TRUE to continue processing
-
before - before the request; for injecting session specific data to
request handler; return value is passed to request handler
as arg_list
-
request - main request handling is done here; should return a valid
response, otherwise error 500 is raised.
-
after - after the request; can be used to inspect the response
(but not modify it) before sending to the client;
return value is discarded
Usage
App$handle_request(
event = c("header", "before", "request", "after"),
name,
handler,
...,
position = NULL
)
Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_ws()
Websocket Event Handler
Arguments
-
server - application itself
-
id - client identifier
-
request - request used to establish the websocket connection
-
message - message itself
-
arg_list - for message event, the return value from the before
handler, if any.
-
binary - for message event, indicating if it is binary.
-
response - for after event, the response object
Events
-
before - before the request; for decoding the message before passing
it through; return value is passed to request handler
as arg_list
-
message - main message handling is done here; return value discarded
-
after - after the request; can be used to inspect the response
(but not modify it) before sending to the client;
return value is discarded
-
send - a websocket message is sent; return value discarded
Usage
App$handle_ws(
event = c("before", "message", "after", "send", "closed"),
name,
handler,
...,
position = NULL
)
Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_trigger()
handle Triggers an event for the handlers
Usage
App$handle_trigger(event, ..., check = TRUE)
Arguments
event(str) event name
...(arg) args passed to handler
check(flg) check whether this is protected
Method router()
Adds a route handler
Usage
App$router(
path,
handler,
...,
name = path,
methods = "get",
attach = "request",
priority = 0L,
replace = FALSE
)
Arguments
path(str) endpoint
handler(fun) handler; must have arguments
request, response, keys, ....
...(dta) extra metadata to identify thion_atts route.
name(str) human-readable friendly name
methods(chr) combination of GET, POST, PUT, PATCH, DELETE
attach(str) event to attach. defaults to request.
priority(int) relative positioning of the handler; lower will be
executed first.
replace(flg) whether or not to replace same name or error out
Method router_find()
Find routers based on metadata
Usage
App$router_find(
...,
attach = c("request", "message", "header"),
discard = FALSE
)
Arguments
...(sel) selector expressions
attach(str) whether to use the request, message, or header stack
discard(flg) if TRUE, then selected is discarded instead of kept
Method router_remove()
Remove routers based on metadata
Usage
App$router_remove(
...,
attach = c("request", "message", "header"),
discard = FALSE
)
Arguments
...(arg) extra arguments
attach(str) whether to use the request, message, or header stack
discard(flg) if TRUE, then selected is discarded instead of kept
Method static()
Adds a route for server static files
Usage
App$static(
path,
file,
...,
name = path,
index_html = TRUE,
fallthrough = FALSE,
html_charset = "utf-8",
headers = list(),
validation = character(0),
replace = FALSE
)
Arguments
path(url) URL path to serve
file(pth) directory to serve on that path
...(dta) extra metadata to identify this static path.
name(str) human-readable friendly name
index_html(flg) whether or not to serve when index.html exists
fallthrough(flg) if not available, use R callback
html_charset(str) html charset, defaults to UTF-8
headers(lst) headers that are included with the response
validation(chr) character vector of headers needed
replace(flg) if already exists, overwrite
Method static_find()
Find static paths based on metadata
Usage
App$static_find(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method static_remove()
Remove static paths based on metadata
Usage
App$static_remove(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method ws_send()
Send a websocket message
Usage
App$ws_send(message, id)
Arguments
message(lst) websocket message
id(str) client identifier; all clients if missing (for send)
Method ws_close()
Close a websocket connection
Usage
App$ws_close(id)
Arguments
id(str) client identifier
Method plugin_attach()
Attach a plugin
Usage
App$plugin_attach(plugin, ..., force = FALSE, bind = TRUE, clean = TRUE)
Arguments
plugin(Plugin) instance
...(arg) passed to the plugin's on_attach method
force(flg) force to attach even if there is already existing
bind(flg) add an active binding to fetch the plugin itself
clean(flg) remove the attach methods once they have already
been run to clean up the interface
Method plugin_detach()
Detach a plugin
Usage
App$plugin_detach(name, ...)
Arguments
name(str) name of the plugin to detach
...(arg) extra arguments
Method plugin_detach_all()
Detach all plugins
Usage
App$plugin_detach_all(...)
Arguments
...(arg) extra arguments
Method plugin_has()
Check if a plugin of a class is attached
Usage
App$plugin_has(class)
Arguments
class(str) class of the plugin
Method plugin_get()
Check if a plugin of a class is attached
Usage
App$plugin_get(class)
Arguments
class(str) class of the plugin
Method print()
print method
Usage
App$print()
tjpalanca/webtools documentation built on Dec. 23, 2021, 11 a.m.
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Description Super class Active bindings Methods
Description
Overview
Web Application object based on fiery::Fire via Fire and
contains the following modifications:
Takes advantage of
httpuv::staticPath()viaFireto serve, assets which "happens entirely within the I/O thread, so doing so will not block or be blocked by activity in the main R thread."Incorporates the
routrpackage for routing, instead of relying on the user to create it separately.Adds load testing, profiling, and benchmarking functionality for the app itself and for individual routers.
Methods return the
selfobject to allow method chaining.Renames some methods to conform to some sort of prefixing structure for better discovery.
Methods
-
Lifecycle (
lifecycle_)Lifecycle handlers handle starting, stopping, and other development utilities for web applications.
-
Settings (
set_)set clients, headers, and other things that are globally applicable to this application instance.
-
Data (
data)arbitrary data that can be set or retrieved from the object data store.
-
Handlers (
handle_)Handlers are functions that run on a specific event trigger.
-
Routers (
route_)create handlers for specific virtual paths.
-
Static Paths (
static_)create static paths for serving static files from disk.
-
Websockets (
ws_)WebSocket is a bi-directional communication protocol that is very useful when you need to persistently poll or receive new information.
It's also useful to set the ID with
set_clientsso that they can easily be identified.
-
Plugins (
plugin_)Fiery functionality allows you to add plugins. See here for more information on how to use plugins. The interface implemented is similar except that we have access to the whole object not just to the contained
Fireobject.
Details
Super class
webtools::Configurable -> App
Active bindings
pluginsread-only field for plugins attached
fireread-only field for the fire object
handlesread-only field for the handles attached
routersread-only field for the routers attached
staticsread-only field for the paths attached
dataalternative way of accessing application data
socketsread-only list of active websockets
eventshelp information
Methods
Public methods
Inherited methods
Method new()
Create a new Application
Usage
App$new(
...,
host = "0.0.0.0",
port = 3838L,
root = "",
headers = NULL,
client_id_converter = function(request) { request$trust <- TRUE
return(request$ip) },
path_extractor = function(msg, bin) "/",
refresh_rate = 0.001,
refresh_rate_nb = 0.001,
trigger_dir = NULL,
access_log_format = common_log_format,
logger = if (interactive()) { logger_console() } else { logger_null() }
)Arguments
...(Plugin)s to attach to this Application Instance
host(str) IP address; defaults to all addresses.
port(int) port number from 0 to 65535.
root(str) path at which fiery will serve requests
headers(lst) global header that will be set on all responses
client_id_converter(fun) function that converts a request into a client ID
path_extractor(fun) function that converts a message to a path on which to dispatch
refresh_rate(num) blocking refresh rate for run cycles
refresh_rate_nb(num) non-blocking refresh rate for run cycles
trigger_dir(path) directory in which you can save RDS files of lists where the
external-eventtrigger will be triggered with the list as arguments. See events.access_log_format(str/fn) provider of the logging service.
logger(fn) logger for this application.
Method browse()
Browse to the App URL
Usage
App$browse()
Method finalize()
Finalizer
Usage
App$finalize()
Method lifecycle_start()
Start the application
Usage
App$lifecycle_start(..., block = FALSE, browse = FALSE, silent = FALSE)
Arguments
...(args) passed to the
startorresumehandlerblock(flag) blocking server
browse(flag) open a browser after starting
silent(flag) do not log to console
Method lifecycle_stop()
Stop the application
Usage
App$lifecycle_stop()
Method lifecycle_is_running()
Checks if the app is still running
Usage
App$lifecycle_is_running()
Method set_client_id_converter()
Set client converter
Usage
App$set_client_id_converter(client_id_converter)
Arguments
client_id_converter(fun) takes request and returns client ID
Method set_path_extractor()
Set the path extractor
Usage
App$set_path_extractor(extractor)
Arguments
extractorfunction that takes the message and returns a path
Method set_headers()
Set the heaers to be sent with every response
Usage
App$set_headers(..., .list = NULL)
Arguments
...(arg) key-value pairs
.list(lst) provide the values as a list
Method set_logger()
Set the logger function
Usage
App$set_logger(logger)
Arguments
logger(fun) logger function; there are some presets:
-
logger_null()- onlyerror,warning,messageevents -
logger_console()- everything to console -
logger_file()- everything to file -
logger_switch()- file or console dependeing on need
Can also be any function that takes arguments:
event,message,request = NULL,time = Sys.time(), and....-
Method set_data()
set data inside the app object; list merge semantics
Usage
App$set_data(name, value)
Arguments
name(str) name of the data
value(arg) key value data
Method get_data()
get data inside the app object
Usage
App$get_data(name)
Arguments
name(str) name of the data
Method clear_data()
clear all data in side the app object
Usage
App$clear_data()
Method log()
Send an application log
Usage
App$log(event, message, request = NULL, ..., .envir = parent.frame())
Arguments
event(str) event attached
message(str) glue string
request(req) reqres::Request object
...(arg) extra arguments
.envir(env) calling environment
Method handle()
Attach a handler to an event
Usage
App$handle(event, name, handler, ..., position = NULL)
Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_find()
Find a handler to an event
Usage
App$handle_find(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method handle_remove()
Remove a handler
Usage
App$handle_remove(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method handle_lifecycle()
Lifecycle Handler
Triggered once per server invocation. Return value is ignored.
Arguments
-
server- application itself -
...- extra arguments
Events
-
start/resume- app is started, but not running;resumeis whenapp_start(resume = TRUE)is called. -
end- when app is stopped usingapp_stop().
Usage
App$handle_lifecycle(
event = c("start", "resume", "end"),
name,
handler,
...,
position = NULL
)Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_cycle()
Cycle Handler
Triggered for every event loop. Return value is ignored.
Arguments
-
server- application
Events
-
start- beginning of the loop; pre-logging. -
end- end of the loop; post-logging.
Usage
App$handle_cycle(
event = c("start", "end"),
name,
handler,
...,
position = NULL
)Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_request()
Request Handler
Triggered by actual request made to the web server.
Arguments
-
server- application itself -
id- client identifier -
request- request itself -
arg_list- forrequestevent, the return value from thebeforehandler, if any. -
response- forafterevent, the response object
Events
-
header- when HTTP headers are received; returnFALSEto short-circuit; returnTRUEto continue processing -
before- before the request; for injecting session specific data to request handler; return value is passed torequesthandler asarg_list -
request- main request handling is done here; should return a valid response, otherwise error 500 is raised. -
after- after the request; can be used to inspect the response (but not modify it) before sending to the client; return value is discarded
Usage
App$handle_request(
event = c("header", "before", "request", "after"),
name,
handler,
...,
position = NULL
)Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_ws()
Websocket Event Handler
Arguments
-
server- application itself -
id- client identifier -
request- request used to establish the websocket connection -
message- message itself -
arg_list- formessageevent, the return value from thebeforehandler, if any. -
binary- formessageevent, indicating if it is binary. -
response- forafterevent, the response object
Events
-
before- before the request; for decoding the message before passing it through; return value is passed torequesthandler asarg_list -
message- main message handling is done here; return value discarded -
after- after the request; can be used to inspect the response (but not modify it) before sending to the client; return value is discarded -
send- a websocket message is sent; return value discarded
Usage
App$handle_ws(
event = c("before", "message", "after", "send", "closed"),
name,
handler,
...,
position = NULL
)Arguments
event(str) name of the event to respond to
name(str) human-readable name for easy identification
handler(fun) handler for the event
...(arg) key value pairs of attributes to attach to handler
position(int) position in the handler stack; default last
Method handle_trigger()
handle Triggers an event for the handlers
Usage
App$handle_trigger(event, ..., check = TRUE)
Arguments
event(str) event name
...(arg) args passed to handler
check(flg) check whether this is protected
Method router()
Adds a route handler
Usage
App$router( path, handler, ..., name = path, methods = "get", attach = "request", priority = 0L, replace = FALSE )
Arguments
path(str) endpoint
handler(fun) handler; must have arguments
request,response,keys,.......(dta) extra metadata to identify thion_atts route.
name(str) human-readable friendly name
methods(chr) combination of GET, POST, PUT, PATCH, DELETE
attach(str) event to attach. defaults to
request.priority(int) relative positioning of the handler; lower will be executed first.
replace(flg) whether or not to replace same name or error out
Method router_find()
Find routers based on metadata
Usage
App$router_find(
...,
attach = c("request", "message", "header"),
discard = FALSE
)Arguments
...(sel) selector expressions
attach(str) whether to use the request, message, or header stack
discard(flg) if TRUE, then selected is discarded instead of kept
Method router_remove()
Remove routers based on metadata
Usage
App$router_remove(
...,
attach = c("request", "message", "header"),
discard = FALSE
)Arguments
...(arg) extra arguments
attach(str) whether to use the request, message, or header stack
discard(flg) if TRUE, then selected is discarded instead of kept
Method static()
Adds a route for server static files
Usage
App$static( path, file, ..., name = path, index_html = TRUE, fallthrough = FALSE, html_charset = "utf-8", headers = list(), validation = character(0), replace = FALSE )
Arguments
path(url) URL path to serve
file(pth) directory to serve on that path
...(dta) extra metadata to identify this static path.
name(str) human-readable friendly name
index_html(flg) whether or not to serve when index.html exists
fallthrough(flg) if not available, use R callback
html_charset(str) html charset, defaults to UTF-8
headers(lst) headers that are included with the response
validation(chr) character vector of headers needed
replace(flg) if already exists, overwrite
Method static_find()
Find static paths based on metadata
Usage
App$static_find(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method static_remove()
Remove static paths based on metadata
Usage
App$static_remove(..., discard = FALSE)
Arguments
...(arg) extra arguments
discard(flg) if TRUE, then selected is discarded instead of kept
Method ws_send()
Send a websocket message
Usage
App$ws_send(message, id)
Arguments
message(lst) websocket message
id(str) client identifier; all clients if missing (for send)
Method ws_close()
Close a websocket connection
Usage
App$ws_close(id)
Arguments
id(str) client identifier
Method plugin_attach()
Attach a plugin
Usage
App$plugin_attach(plugin, ..., force = FALSE, bind = TRUE, clean = TRUE)
Arguments
plugin(Plugin) instance
...(arg) passed to the plugin's
on_attachmethodforce(flg) force to attach even if there is already existing
bind(flg) add an active binding to fetch the plugin itself
clean(flg) remove the attach methods once they have already been run to clean up the interface
Method plugin_detach()
Detach a plugin
Usage
App$plugin_detach(name, ...)
Arguments
name(str) name of the plugin to detach
...(arg) extra arguments
Method plugin_detach_all()
Detach all plugins
Usage
App$plugin_detach_all(...)
Arguments
...(arg) extra arguments
Method plugin_has()
Check if a plugin of a class is attached
Usage
App$plugin_has(class)
Arguments
class(str) class of the plugin
Method plugin_get()
Check if a plugin of a class is attached
Usage
App$plugin_get(class)
Arguments
class(str) class of the plugin
Method print()
print method
Usage
App$print()
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