gleam/http/middleware

Types

Middleware

pub type Middleware(
  before_req,
  before_resp,
  after_req,
  after_resp,
) =
  fn(Service(before_req, before_resp)) ->
    Service(after_req, after_resp)

Functions

map_resp_body

pub fn map_resp_body(
  service: fn(Request(a)) -> Response(b),
  with mapper: fn(b) -> c,
) -> fn(Request(a)) -> Response(c)

A middleware that transform the response body returned by the service using a given function.

method_override

pub fn method_override(
  service: fn(Request(a)) -> Response(b),
) -> fn(Request(a)) -> Response(b)

A middleware that overrides an incoming POST request with a method given in the request's _method query paramerter. This is useful as web browsers typically only support GET and POST requests, but our application may expect other HTTP methods that are more semantically correct.

The methods PUT, PATCH, and DELETE are accepted for overriding, all others are ignored.

The _method query paramerter can be specified in a HTML form like so:

<form method="POST" action="/item/1?_method=DELETE">
  <button type="submit">Delete item</button>
</form>

prepend_resp_header

pub fn prepend_resp_header(
  service: fn(Request(a)) -> Response(b),
  key: String,
  value: String,
) -> fn(Request(a)) -> Response(b)

A middleware that prepends a header to the request.