Responses

Each HTTP request served by Rwf is expected to return a response. If your app is using a REST API, responses are typically JSON. If you prefer HTML over the wire or plain old websites, the responses will contain HTML or text.

Creating responses

To create a response, you can just instantiate the Response struct and populate the body with the right content. The most popular response types have their own instantiation methods:

HTMLJSONPlain text

let response = Response::new()
  .html("<h1>Big letters!</h1>");

let json = serde_json::json!({
  "id": 5,
  "email": "test@example.com"
});

let response = Response::new().json(json)?;

let response = Response::new()
  .text("One apple a day keeps the doctor away!");

Using one of those methods will automatically set the right Content-Type and Content-Length headers.

Raw data

If your endpoint is sending binary data or some data type we don't have a method for, you can always set the body and content type manually:

let mystery_bytes: Vec<u8> = vec![1, 1, 2, 3, 5, 8, 13];

let response = Response::new()
  .body(mystery_bytes)
  .header("Content-Type", "x-application/fibonacci");

Note

Response attempts to deduce the Content-Type by the body type, so if you want to override its decision, set the header after setting the body on the response. By default, Vec<u8> uses the Content-Type: application/octet-stream.

The Content-Length header is always set automatically, but if you absolutely need to, you can set it manually.

Headers

Setting custom headers can be done with the header method, for example:

let response = Response::new()
  .header("X-My-Header", "My value")
  .header("Cache", "no-store");

Headers are rewritten to lowercase lettering, i.e. X-My-Header and x-my-header are equivalent.

HTTP codes

A Response returns with HTTP code 200 - OK by default. If you want to set a different code, you can:

let response = Response::new()
    .html("<h1>Created!</h1>")
    .code(201);

Common use cases have their own methods to make this easier.

Redirect

Redirecting the user to a different URL can be done with:

let response = Response::new()
    .redirect("/different-url");

This automatically sets the Location and Cache-Control headers, and returns with HTTP code 302 - Found.

Errors

Common errors have their own methods which will return the correct HTTP response code and built-in response body.

404 - Not found

Commonly used when some resource doesn't exist, HTTP response code 404 - Not Found can be returned with:

let response = Response::not_found();

HTTP 404 is returned automatically by Rwf when a user requests a route that doens't have a controller.

403 - Forbidden

When your users have failed some authentication challenge, you can block access to a resource with HTTP response code 403 - Forbidden:

let resonse = Response::forbidden();

Use this one if your frontend can handle it gracefully. If not, a gentle redirect to your login page may be preferable.

Syntactic sugar

Returning certain types of responses is common, so Rwf has a few automatic conversions to remove boilerplate from controllers. In the context of a controller method, the following statements are equivalent.

HTML

ShortcutCode

"<h1>Text</h1>".into()

Response::new().html("<h1>Text</h1>")

JSON