This document explains step-by-step the sample presented in the Quickstart document.

Many implementations are provided and documented in Server.

Creating an application

An application is defined by a function that respects the VSGI.ApplicationCallback delegate. The Router provides handle for that purpose along with powerful routing facilities for client requests.

var app = new Router ();

Binding a route

An application constitute of a list of routes matching and handling user requests. The router provides helpers to declare routes which internally use Route instances.

app.get ("/", (req, res, next, context) => {
    return res.expand_utf8 ("Hello world!", null);

Every route declaration has a callback associated that does the request processing. The callback, named handler, receives four arguments:

  • a Request that describes a resource being requested
  • a Response that correspond to that resource
  • a next continuation to keep routing
  • a routing context to retrieve and store states from previous and for following handlers


For an alternative, more structured approach to route binding, see Cleaning up route logic

Serving the application

This part is pretty straightforward: you create a server that will serve your application at port 3003 and since http was specified, it will be served with HTTP.

Server.new_with_application ("http", "org.valum.example.App", app.handle).run ({"app", "--port", "3003"});

Server takes an application identifier and an ApplicationCallback, which is respected by the handle function.

Minimal application can be defined using a simple lambda function taking a Request and Response.

Server.new_with_application ("http", "org.valum.example.App", (req, res) => {
    res.status = 200;
    return res.expand ("Hello world!", null);
}).run ({"app", "--port", "3003"});

Usually, you would only pass the CLI arguments to run, so that your runtime can be parametrized easily, but in this case we just want our application to run with fixed parameters. Options are documented per implementation.

public static void main (string[] args) {
    var app = new Router ();

    // assume some route declarations...

    Server.new_with_application ("http", "org.valum.example.App", app.handle).run (args);