RestRserve (version 0.1.0.10)

RestRserveApplication: Creates RestRserveApplication.

Description

Creates RestRserveApplication object. RestRserveApplication facilitates in turning user-supplied R code into high-performance REST API by allowing to easily register R functions for handling http-requests.

Usage

RestRserveApplication

Format

R6Class object.

Usage

• app = RestRserveApplication$new()

• app$add_route(path = "/echo", method = "GET", FUN = function(request) { RestRserve::create_response(body = request$query[[1]], content_type = "text/plain") })

• app$routes()

For usage details see Methods, Arguments and Examples sections.

Methods

$new()

Constructor for RestRserveApplication. For the moment doesn't take any parameters.

$add_route(path, method, FUN, path_as_prefix = FALSE, ...)

Adds endpoint and register user-supplied R function as a handler. User function FUN must return object of the class "RestRserveResponse" which can be easily constructed with create_response. path_as_prefix at the moment used mainly to help with serving static files. Probably in future it will be replaced with other argument to perform URI template matching.

$add_get(path, FUN, ...)

shorthand to add_route with GET method

$add_post(path, FUN, ...)

shorthand to add_route with POST method

$add_static(path, file_path, content_type = NULL, ...)

adds GET method to serve file or directory at file_path. If content_type = NULL then MIME code content_type will be inferred automatically (from file extension). If it will be impossible to guess about file type then content_type will be set to "application/octet-stream"

$run(http_port = 8001L, ...)

starts RestRserve application from current R session. http_port - http port for application. ... - key-value pairs of the Rserve configuration. If contains "http.port" then http_port will be silently replaced with its value. background - whether to try to launch in background process on UNIX systems. Ignored in windows.

$call_handler(request)

Used internally, usually users don't need to call it. Calls handler function for a given request.

$routes()

Lists all registered routes

$print_endpoints_summary()

Prints all the registered routes with allowed methods

$set_404_handler(FUN)

Register custom 404 response handler. FUN should be a function which takes exactly one argument - request and return RestRserveResponse object. Default handler is FUN = function(request) http_404_not_found(). See http_404_not_found for details

$add_openapi(path = "/openapi.yaml", openapi = openapi_create())

Adds endpoint to serve OpenAPI description of available methods.

$add_swagger_ui(path = "/swagger", path_openapi = "/openapi.yaml", path_swagger_assets = "/__swagger__/", file_path = tempfile(fileext = ".html"))

Adds endpoint to show swagger-ui.

Arguments

app

A RestRserveApplication. object

path

character of length 1. Should be valid path for example '/a/b/c'

method

character of length 1. At the moment one of "GET", "POST", "HEAD"

FUN

function which takes exactly one argument - request. request R object returned by RestRserve:::parse_request() function. Object corresponds to http-request and essentially request is a list with a fixed set of fields. Representation of the "GET" request to "http://localhost:8001/somemethod?a=1&b=2" will look like:

path

= "/somepath", always character of length 1

method

= "GET", always character of length 1

query

= c("a" = "1", "b" = "2"), named character vector. Queiry parameters key-value pairs.

body

= NULL.

• NULL if the http body is empty or zero length.

• raw vector with a "content-type" attribute in all cases except URL encoded form (if specified in the headers)

• named characeter vector in the case of a URL encoded form. It will have the same shape as the query string (named string vector).

content_type

= "", always character of length 1

headers

= c("a" = "1", "b" = "2"), named character vector. key-value pairs from http-header.

Examples

# NOT RUN {
echo_handler = function(request) {
 RestRserve::create_response(body = request$query[[1]],
                             content_type = "text/plain",
                            headers = "Location: /echo",
                            status_code = 201L)
}
app = RestRserveApplication$new()
app$add_route(path = "/echo", method = "GET", FUN = echo_handler)
req = list(query = c("a" = "2"), method = "GET", path = "/echo")
answer = app$call_handler(request = req)
answer$body
# "2"
# }