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Create HTTP Handler

Source: R/server.R
handler.Rd

Creates an HTTP route handler for use with http_server().

Usage

handler(path, callback, method = "GET", prefix = FALSE)

Arguments

path

URI path to match (e.g., "/api/data", "/users").

callback

Function to handle requests. Receives a list with:

  • method - HTTP method (character)

  • uri - Request URI (character)

  • headers - Named character vector of headers

  • body - Request body (raw vector)

Should return a list with:

  • status - HTTP status code (integer, default 200)

  • headers - Response headers as a named character vector, e.g. c("Content-Type" = "application/json") (optional)

  • body - Response body (character or raw)

method

[default "GET"] HTTP method to match (e.g., "GET", "POST", "PUT", "DELETE"). Use "*" to match any method.

prefix

[default FALSE] Logical, if TRUE matches path as a prefix (e.g., "/api" will match "/api/users", "/api/items", etc.).

Value

A handler object for use with http_server().

Details

If the callback throws an error, a 500 Internal Server Error response is returned to the client.

See also

handler_ws() for WebSocket handlers. Static handlers: handler_file(), handler_directory(), handler_inline(), handler_redirect().

Examples

# Simple GET handler
h1 <- handler("/hello", function(req) {
  list(status = 200L, body = "Hello!")
})

# POST handler that echoes the request body
h2 <- handler("/echo", function(req) {
  list(status = 200L, body = req$body)
}, method = "POST")

# Catch-all handler for a path prefix
h3 <- handler("/static", function(req) {
  # Serve static files under /static/*
}, method = "*", prefix = TRUE)