Package Plumber Router
Package Plumber Router
Package Plumber Router
Routers are the core request handler in plumber. A router is responsible for taking an incoming request, submitting it through the appropriate filters and eventually to a corresponding endpoint, if one is found.
See the Programmatic Usage article for additional details on the methods available on this object.
## ------------------------------------------------ ## Method `Plumber$mount` ## ------------------------------------------------ ## Not run: root <- pr() users <- Plumber$new("users.R") root$mount("/users", users) products <- Plumber$new("products.R") root$mount("/products", products) ## End(Not run) ## ------------------------------------------------ ## Method `Plumber$registerHook` ## ------------------------------------------------ ## Not run: pr <- pr() pr$registerHook("preroute", function(req){ cat("Routing a request for", req$PATH_INFO, "...\n") }) pr$registerHooks(list( preserialize=function(req, value){ print("About to serialize this value:") print(value) # Must return the value since we took one in. Here we're not choosing # to mutate it, but we could. value }, postserialize=function(res){ print("We serialized the value as:") print(res$body) } )) pr$handle("GET", "/", function(){ 123 }) ## End(Not run) ## ------------------------------------------------ ## Method `Plumber$handle` ## ------------------------------------------------ ## Not run: pr <- pr() pr$handle("GET", "/", function(){ "<html><h1>Programmatic Plumber!</h1></html>" }, serializer=plumber::serializer_html()) ## End(Not run) ## ------------------------------------------------ ## Method `Plumber$setSerializer` ## ------------------------------------------------ ## Not run: pr <- pr() pr$setSerializer(serializer_unboxed_json()) ## End(Not run) ## ------------------------------------------------ ## Method `Plumber$set404Handler` ## ------------------------------------------------ ## Not run: pr <- pr() pr$set404Handler(function(req, res) {cat(req$PATH_INFO)}) ## End(Not run) ## ------------------------------------------------ ## Method `Plumber$setErrorHandler` ## ------------------------------------------------ ## Not run: pr <- pr() pr$setErrorHandler(function(req, res, err) { message("Found error: ") str(err) }) ## End(Not run)
pr(), pr_run(), pr_get(), pr_post(), pr_mount(), pr_hook(), pr_hooks(), pr_cookie(), pr_filter(), pr_set_api_spec(), pr_set_docs(), pr_set_serializer(), pr_set_parsers(), pr_set_404(), pr_set_error(), pr_set_debug(), pr_set_docs_callback()
plumber::Hookable -> Plumber
flags: For internal use only
endpoints: Plumber router endpoints read-only
filters: Plumber router filters read-only
mounts: Plumber router mounts read-only
environment: Plumber router environment read-only
routes: Plumber router routes read-only
new()Create a new Plumber router
See also plumb(), pr()
Plumber$new(file = NULL, filters = defaultPlumberFilters, envir)
file: path to file to plumb
filters: a list of Plumber filters
envir: an environment to be used as the enclosure for the routers execution
A new Plumber router
run()Start a server using Plumber object.
See also: pr_run()
Plumber$run(
host = "127.0.0.1",
port = get_option_or_env("plumber.port", NULL),
swagger = deprecated(),
debug = missing_arg(),
swaggerCallback = missing_arg(),
...,
docs = missing_arg(),
quiet = FALSE
)
host: a string that is a valid IPv4 or IPv6 address that is owned by this server, which the application will listen on. "0.0.0.0" represents all IPv4 addresses and "::/0" represents all IPv6 addresses.
port: a number or integer that indicates the server port that should be listened on. Note that on most Unix-like systems including Linux and Mac OS X, port numbers smaller than 1025 require root privileges.
This value does not need to be explicitly assigned. To explicitly set it, see `options_plumber()`.
swagger: Deprecated. Please use docs instead. See $setDocs(docs) or $setApiSpec() for more customization.
debug: If TRUE, it will provide more insight into your API errors. Using this value will only last for the duration of the run. If a $setDebug() has not been called, debug will default to FALSE at $run() time. See $setDebug() for more details.
swaggerCallback: An optional single-argument function that is called back with the URL to an OpenAPI user interface when one becomes ready. If missing, defaults to information previously set with $setDocsCallback(). This value will only be used while running the router.
...: Should be empty.
docs: Visual documentation value to use while running the API. This value will only be used while running the router. If missing, defaults to information previously set with setDocs(). For more customization, see $setDocs() or pr_set_docs() for examples.
quiet: If TRUE, don't print routine startup messages.
mount()Mount a Plumber router
Plumber routers can be “nested” by mounting one into another using the mount() method. This allows you to compartmentalize your API by paths which is a great technique for decomposing large APIs into smaller files.
See also: pr_mount()
Plumber$mount(path, router)
path: a character string. Where to mount router.
router: a Plumber router. Router to be mounted.
\dontrun{
root <- pr()
users <- Plumber$new("users.R")
root$mount("/users", users)
products <- Plumber$new("products.R")
root$mount("/products", products)
}
unmount()Unmount a Plumber router
Plumber$unmount(path)
path: a character string. Where to unmount router.
registerHook()Register a hook
Plumber routers support the notion of "hooks" that can be registered to execute some code at a particular point in the lifecycle of a request. Plumber routers currently support four hooks:
preroute(data, req, res)postroute(data, req, res, value)preserialize(data, req, res, value)postserialize(data, req, res, value)In all of the above you have access to a disposable environment in the data
parameter that is created as a temporary data store for each request. Hooks can store temporary data in these hooks that can be reused by other hooks processing this same request.
One feature when defining hooks in Plumber routers is the ability to modify the returned value. The convention for such hooks is: any function that accepts a parameter named value is expected to return the new value. This could be an unmodified version of the value that was passed in, or it could be a mutated value. But in either case, if your hook accepts a parameter named value, whatever your hook returns will be used as the new value for the response.
You can add hooks using the registerHook method, or you can add multiple hooks at once using the registerHooks method which takes a name list in which the names are the names of the hooks, and the values are the handlers themselves.
See also: pr_hook(), pr_hooks()
Plumber$registerHook(
stage = c("preroute", "postroute", "preserialize", "postserialize", "exit"),
handler
)
stage: a character string. Point in the lifecycle of a request.
handler: a hook function.
\dontrun{
pr <- pr()
pr$registerHook("preroute", function(req){
cat("Routing a request for", req$PATH_INFO, "...\n")
})
pr$registerHooks(list(
preserialize=function(req, value){
print("About to serialize this value:")
print(value)
# Must return the value since we took one in. Here we're not choosing
# to mutate it, but we could.
value
},
postserialize=function(res){
print("We serialized the value as:")
print(res$body)
}
))
pr$handle("GET", "/", function(){ 123 })
}
handle()Define endpoints
The “handler” functions that you define in these handle calls are identical to the code you would have defined in your plumber.R file if you were using annotations to define your API. The handle() method takes additional arguments that allow you to control nuanced behavior of the endpoint like which filter it might preempt or which serializer it should use.
See also: pr_handle(), pr_get(), pr_post(), pr_put(), pr_delete()
Plumber$handle(
methods,
path,
handler,
preempt,
serializer,
parsers,
endpoint,
...
)
methods: a character string. http method.
path: a character string. Api endpoints
handler: a handler function.
preempt: a preempt function.
serializer: a serializer function.
parsers: a named list of parsers.
endpoint: a PlumberEndpoint object.
...: additional arguments for PlumberEndpoint new method (namely lines, params, comments, responses and tags. Excludes envir).
\dontrun{
pr <- pr()
pr$handle("GET", "/", function(){
"<html><h1>Programmatic Plumber!</h1></html>"
}, serializer=plumber::serializer_html())
}
removeHandle()Remove endpoints
Plumber$removeHandle(methods, path, preempt = NULL)
methods: a character string. http method.
path: a character string. Api endpoints
preempt: a preempt function.
print()Print representation of plumber router.
Plumber$print(prefix = "", topLevel = TRUE, ...)
prefix: a character string. Prefix to append to representation.
topLevel: a logical value. When method executed on top level router, set to TRUE.
...: additional arguments for recursive calls
A terminal friendly representation of a plumber router.
serve()Serve a request
Plumber$serve(req, res)
req: request object
res: response object
route()Route a request
Plumber$route(req, res)
req: request object
res: response object
call()httpuv interface call function. (Required for httpuv)
Plumber$call(req)
req: request object
onHeaders()httpuv interface onHeaders function. (Required for httpuv)
Plumber$onHeaders(req)
req: request object
onWSOpen()httpuv interface onWSOpen function. (Required for httpuv)
Plumber$onWSOpen(ws)
ws: WebSocket object
setSerializer()Sets the default serializer of the router.
See also: pr_set_serializer()
Plumber$setSerializer(serializer)
serializer: a serializer function
\dontrun{
pr <- pr()
pr$setSerializer(serializer_unboxed_json())
}
setParsers()Sets the default parsers of the router. Initialized to c("json", "form", "text", "octet", "multi")
Plumber$setParsers(parsers)
parsers: Can be one of:
* A `NULL` value
* A character vector of parser names
* A named `list()` whose keys are parser names names and values are arguments to be applied with `do.call()`
* A `TRUE` value, which will default to combining all parsers. This is great for seeing what is possible, but not great for security purposes
If the parser name `"all"` is found in any character value or list name, all remaining parsers will be added. When using a list, parser information already defined will maintain their existing argument values. All remaining parsers will use their default arguments.
Example:
```
# provide a character string
parsers = "json"
# provide a named list with no arguments
parsers = list(json = list())
# provide a named list with arguments; include `rds`
parsers = list(json = list(simplifyVector = FALSE), rds = list())
# default plumber parsers
parsers = c("json", "form", "text", "octet", "multi")
```
set404Handler()Sets the handler that gets called if an incoming request can’t be served by any filter, endpoint, or sub-router.
See also: pr_set_404()
Plumber$set404Handler(fun)
fun: a handler function.
\dontrun{
pr <- pr()
pr$set404Handler(function(req, res) {cat(req$PATH_INFO)})
}
setErrorHandler()Sets the error handler which gets invoked if any filter or endpoint generates an error.
See also: pr_set_404()
Plumber$setErrorHandler(fun)
fun: a handler function.
\dontrun{
pr <- pr()
pr$setErrorHandler(function(req, res, err) {
message("Found error: ")
str(err)
})
}
setDocs()Set visual documentation to use for API
See also: pr_set_docs(), register_docs(), registered_docs()
Plumber$setDocs(docs = get_option_or_env("plumber.docs", TRUE), ...)
docs: a character value or a logical value. See pr_set_docs() for examples. If using options_plumber(), the value must be set before initializing your Plumber router.
...: Arguments for the visual documentation. See each visual documentation package for further details.
setDocsCallback()Set a callback to notify where the API's visual documentation is located.
When set, it will be called with a character string corresponding to the API docs url. This allows RStudio to locate visual documentation.
If using options_plumber(), the value must be set before initializing your Plumber router.
See also: pr_set_docs_callback()
Plumber$setDocsCallback(
callback = get_option_or_env("plumber.docs.callback", NULL)
)
callback: a callback function for taking action on the docs url. (Also accepts NULL values to disable the callback.)
setDebug()Set debug value to include error messages.
See also: $getDebug() and pr_set_debug()
Plumber$setDebug(debug = FALSE)
debug: TRUE provides more insight into your API errors.
getDebug()Retrieve the debug value. If it has never been set, it will return FALSE.
See also: $getDebug() and pr_set_debug()
Plumber$getDebug()
filter()Add a filter to plumber router
See also: pr_filter()
Plumber$filter(name, expr, serializer)
name: a character string. Name of filter
expr: an expr that resolve to a filter function or a filter function
serializer: a serializer function
setApiSpec()Allows to modify router autogenerated OpenAPI Specification
Note, the returned value will be sent through serializer_unboxed_json() which will turn all length 1 vectors into atomic values. To force a vector to serialize to an array of size 1, be sure to call as.list() on your value. list() objects are always serialized to an array value.
See also: pr_set_api_spec()
Plumber$setApiSpec(api = NULL)
api: This can be
* an OpenAPI Specification formatted list object
* a function that accepts the OpenAPI Specification autogenerated by `plumber` and returns a OpenAPI Specification formatted list object.
* a path to an OpenAPI Specification
The value returned will not be validated for OAS compatibility.
getApiSpec()Retrieve OpenAPI file
Plumber$getApiSpec()
addEndpoint()addEndpoint has been deprecated in v0.4.0 and will be removed in a coming release. Please use handle() instead.
Plumber$addEndpoint(
verbs,
path,
expr,
serializer,
processors,
preempt = NULL,
params = NULL,
comments
)
verbs: verbs
path: path
expr: expr
serializer: serializer
processors: processors
preempt: preempt
params: params
comments: comments
addAssets()addAssets has been deprecated in v0.4.0 and will be removed in a coming release. Please use mount and PlumberStatic$new() instead.
Plumber$addAssets(dir, path = "/public", options = list())
dir: dir
path: path
options: options
addFilter()$addFilter() has been deprecated in v0.4.0 and will be removed in a coming release. Please use $filter() instead.
Plumber$addFilter(name, expr, serializer, processors)
name: name
expr: expr
serializer: serializer
processors: processors
addGlobalProcessor()$addGlobalProcessor() has been deprecated in v0.4.0 and will be removed in a coming release. Please use $registerHook(s) instead.
Plumber$addGlobalProcessor(proc)
proc: proc
openAPIFile()Deprecated. Retrieve OpenAPI file
Plumber$openAPIFile()
swaggerFile()Deprecated. Retrieve OpenAPI file
Plumber$swaggerFile()
clone()The objects of this class are cloneable with this method.
Plumber$clone(deep = FALSE)
deep: Whether to make a deep clone.
Useful links