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Controllers

The Controller trait is the lowest-level way to handle HTTP requests in rust-web-server.

The Controller trait

Controller is defined in src/controller/mod.rs and has two static methods:

pub trait Controller {
    fn is_matching(request: &Request, connection: &ConnectionInfo) -> bool;
    fn process(request: &Request, response: Response, connection: &ConnectionInfo) -> Response;
}
  • is_matching — called in declaration order inside App::execute; the first controller that returns true wins.
  • process — receives the partially-built response (already populated with standard headers from Header::get_header_list) and must return it with a status code and body.

Complete minimal example

use rust_web_server::controller::Controller;
use rust_web_server::request::{METHOD, Request};
use rust_web_server::response::{Response, STATUS_CODE_REASON_PHRASE};
use rust_web_server::range::Range;
use rust_web_server::mime_type::MimeType;
use rust_web_server::server::ConnectionInfo;

pub struct HelloController;

impl Controller for HelloController {
    fn is_matching(request: &Request, _conn: &ConnectionInfo) -> bool {
        request.method == METHOD.get && request.request_uri == "/hello"
    }

    fn process(_req: &Request, mut response: Response, _conn: &ConnectionInfo) -> Response {
        response.status_code = *STATUS_CODE_REASON_PHRASE.n200_ok.status_code;
        response.reason_phrase = STATUS_CODE_REASON_PHRASE.n200_ok.reason_phrase.to_string();
        response.content_range_list = vec![
            Range::get_content_range(
                b"Hello, world!".to_vec(),
                MimeType::TEXT_PLAIN.to_string(),
            )
        ];
        response
    }
}

Registering a controller

Controllers are hardcoded in App::execute inside src/app/mod.rs. To add your own, you currently need a custom Application implementation that checks your controller before (or after) the built-in list:

use rust_web_server::application::Application;
use rust_web_server::app::App;
use rust_web_server::controller::Controller;
use rust_web_server::header::Header;
use rust_web_server::request::Request;
use rust_web_server::response::{Response, STATUS_CODE_REASON_PHRASE};
use rust_web_server::server::ConnectionInfo;
use rust_web_server::core::New;

pub struct MyApp;

impl Application for MyApp {
    fn execute(&self, request: &Request, connection: &ConnectionInfo) -> Result<Response, String> {
        // Check custom controllers first
        if HelloController::is_matching(request, connection) {
            let header_list = Header::get_header_list(request);
            let response = Response::get_response(
                STATUS_CODE_REASON_PHRASE.n501_not_implemented,
                Some(header_list),
                None,
            );
            return Ok(HelloController::process(request, response, connection));
        }
        // Fall through to the built-in controller chain
        App::new().execute(request, connection)
    }
}

Built-in controllers

These are registered in App::execute in this order (first match wins):

Controller Matches
IndexController GET / — serves index.html from the static directory
StyleController GET /style.css
ScriptController GET /script.js
DirectoryListingAssetsController GET /rws-directory-listing.css / .js — same-origin CSS/JS for the directory listing page below
FileUploadInitiateController POST /file-upload/initiate
FormUrlEncodedEnctypePostMethodController POST /form-url-encoded-enctype-post-method with application/x-www-form-urlencoded
FormGetMethodController GET /form-get-method (with query parameters)
FormMultipartEnctypePostMethodController POST /form-multipart-enctype-post-method with multipart/form-data
HealthController GET /healthz — returns 200 OK
ReadyController GET /readyz — returns 200 when SERVER_READY is set, 503 otherwise
MetricsController GET /metrics — Prometheus text format
FaviconController GET /favicon.svg
StaticResourceController Any GET for a file found under the static directory; a directory with no index.html renders a directory listing page instead of falling through to 404
NotFoundController Catch-all — returns 404 Not Found
Prefer App::with_state for new routes

For new application routes, App::with_state(S).get(pattern, handler) or the routes! macro is less boilerplate than writing a custom Controller implementation and wiring it into a custom Application. Use Controller when you need matching logic that path patterns cannot express, or when you need to intercept built-in behaviour.

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