(scm net http forms)

application/x-www-form-urlencoded form and query parsing

Overview

(scm net http forms) parses application/x-www-form-urlencoded bodies and query strings into an alist of decoded key/value pairs, with helpers for looking values up.

Common uses

(import (scm net http forms))

(parse-www-form "name=Ada&age=37")
;; => (("name" . "Ada") ("age" . "37"))

(form-ref '(("a" . "1")) "a")        ;; => "1"
(form-ref '() "a" "-")               ;; => "-"   (default when absent)

form-refs-by-prefix collects all entries whose key starts with a given prefix — useful for grouped fields like opt-a, opt-b:

(form-refs-by-prefix '(("opt-a" . "1") ("name" . "x") ("opt-b" . "2")) "opt-")
;; => the opt-* entries

3 bindings

form-ref

Syntax: (form-ref form key [default])
Library: (scm net http forms)
Description: Returns the value of key in form (an alist from parse-www-form),
  or default if missing, or #f if no default is supplied.
Example:
  (form-ref '(("a" . "1")) "a") => "1"
  (form-ref '() "a" "-") => "-"

form-refs-by-prefix

Syntax: (form-refs-by-prefix form prefix)
Library: (scm net http forms)
Description: Returns all (key . value) pairs from form whose key starts with
  prefix. Order is preserved.
Example:
  (form-refs-by-prefix '(("opt-a" . "1") ("name" . "x") ("opt-b" . "2")) "opt-")
  => (("opt-a" . "1") ("opt-b" . "2"))

parse-www-form

Syntax: (parse-www-form body)
Library: (scm net http forms)
Description: Parses an application/x-www-form-urlencoded body or query
  string into an alist of decoded (key . value) string pairs. Empty body
  or #f → '(). Keys with no '=' map to empty-string values.
Example:
  (parse-www-form "name=Ada&age=37") => (("name" . "Ada") ("age" . "37"))
  (parse-www-form "") => ()