Your First App

The smallest Ticket app is one route, one view and a layout. It's the same app as Ticket's examples/hello.

The project file

Make a folder next to your Ticket checkout with a polar.toml. The dependency makes Ticket.* modules available, and the launcher line makes polar run serve your app over HTTP.

[project]
name = "hello"
hosts = ["Node"]

[dependencies]
ticket = { path = "../ticket" }

[run]
launcher = "ticket"
options = { port = 3000 }

A layout

A layout is a plain view that takes the page's Html. Views live in a views zone, and the module has to use Ticket.Html.

module Layout

uses
  Ticket.Html

views
  app(title: String, body: Html)
    <html>
      <head>
        <title>{title}</title>
      </head>
      <body>{body}</body>
    </html>

exports
  app

A view

module Pages

uses
  Ticket.Html

views
  home(name: String)
    <h1>Hello from {name}</h1>

exports
  home

The router

The app's main module exports router(request: Request) -> Option<Response>. Returning None means no route matched, and the launcher answers 404. Here it's written by hand. Real apps let a routes zone generate it.

module Main

uses
  Std.Http
  Std.Option
  Layout
  Pages
  Ticket.Html
  Ticket.Response

hosts
  Node

functions
  router(request: Request) -> Option<Response> {
    if request.path == "/" {
      Some(Response.html(200, Html.document(Layout.app("Hello", Pages.home("Ticket")))))
    } else {
      None
    }
  }

exports
  router

Run it

$ polar run
hello is listening on http://127.0.0.1:3000

GET /      -> 200 <!doctype html><html><head><title>Hello</title></head><body><h1>Hello from Ticket</h1></body></html>
GET /nope  -> 404 {"error":"not found"}