2.11.4 Predefined Formlets

(require web-server/formlets/input)

These formlets are the main combinators for form input.

(make-input render) → (formlet/c (or/c false/c binding?))

render : (string? . -> . xexpr/c)

This formlet is rendered with render, which is passed the input name, and results in the extracted binding.

(text-input  [ #:value value       #:size size       #:max-length max-length       #:read-only? read-only?       #:attributes attrs])

→ (formlet/c (or/c false/c binding?))

value : (or/c false/c bytes?) = #f

size : (or/c false/c exact-nonnegative-integer?) = #f

max-length : (or/c false/c exact-nonnegative-integer?) = #f

read-only? : boolean? = #f

attrs : (listof (list/c symbol? string?)) = empty

This formlet renders using an INPUT element with the TEXT type and the attributes given in the arguments.

(password-input  [ #:value value       #:size size       #:max-length max-length       #:read-only? read-only?       #:attributes attrs])

→ (formlet/c (or/c false/c binding?))

value : (or/c false/c bytes?) = #f

size : (or/c false/c exact-nonnegative-integer?) = #f

max-length : (or/c false/c exact-nonnegative-integer?) = #f

read-only? : boolean? = #f

attrs : (listof (list/c symbol? string?)) = empty

This formlet renders using an INPUT element with the PASSWORD type and the attributes given in the arguments.

(checkbox value checked? [#:attributes attrs])

→ (formlet/c (or/c false/c binding?))

value : bytes?

checked? : boolean?

attrs : (listof (list/c symbol? string?)) = empty

This formlet renders using a INPUT elemen with the CHECKBOX type and the attributes given in the arguments.

(required f) → (formlet/c bytes?)

f : (formlet/c (or/c false/c binding?))

Constructs a formlet that extracts the binding:form-value from the binding produced by f, or errors.

(default def f) → (formlet/c bytes?)

def : bytes?

f : (formlet/c (or/c false/c binding?))

Constructs a formlet that extracts the binding:form-value from the binding produced by f, or returns def.

(to-string f) → (formlet/c string?)

f : (formlet/c bytes?)

Converts f’s output to a string. Equivalent to (cross (pure bytes->string/utf-8) f).

(to-number f) → (formlet/c number?)

f : (formlet/c string?)

Converts f’s output to a number. Equivalent to (cross (pure string->number) f).

(to-symbol f) → (formlet/c symbol?)

f : (formlet/c string?)

Converts f’s output to a symbol. Equivalent to (cross (pure string->symbol) f).

(to-boolean f) → (formlet/c boolean?)

f : (formlet/c bytes?)

Converts f’s output to a boolean, if it is equal to #"on".

input-string : (formlet/c string?)

Equivalent to (to-string (required (text-input))).

input-int : (formlet/c integer?)

Equivalent to (to-number input-string).

input-symbol : (formlet/c symbol?)

Equivalent to (to-symbol input-string).