Tutorial

The following documentation covers the basics of creating a site and all of the features domco provides in addition to Vite. See the Vite documentation for more information and configuration options.

Create a new project

To get started, you’ll need to have Node (recommended), Bun, or Deno or installed on your computer. Then run the create-domco script to create a new project. If you already have an existing client-side Vite project check out the migration instructions.

Node

npm create domco@2.1.0

Bun

bun create domco@2.1.0

Deno

deno run -A npm:create-domco@2.1.0

Entry Points

domco identifies the entry points of your application by file name. These entry points are prefixed with + so they are easily identifiable.

+func

The function entry point is located in within src/server/, this is the server entry point for your application.

src/
└── server/
	└── +func.(js,ts,jsx,tsx)

+func modules export a handler function that takes in a Request, and returns a Response.

// src/server/+func.ts
export const handler = async (req: Request) => {
	return new Response("Hello world");
};

From here, you could route different requests to different responses, based on the req.url.

// src/server/+func.ts
export const handler = async (req: Request) => {
	const { pathname } = new URL(req.url);

	if (pathname === "/") {
		return new Response("Hello");
	} else if (pathname === "/world") {
		return new Response("World");
	}

	return new Response("Not found", { status: 404 });
};

Or check out the examples and add a router.

+page

To create a page, add +page.html file in a directory within src/client/.

domco configures Vite to process each +page.html as a separate entry point automatically. Everything linked in these pages will be bundled and included in the output upon running vite build. You can serve the transformed contents of a page via the client:page virtual module.

src/
├── client/
│	└── +page.html
└── server/
	└── +func.ts

+script

Each +script.(js,ts,jsx,tsx) file within src/client/ will be processed as an entry point by Vite. Client-side scripts can be used in pages via a script tag, or on the server without a page by using the client:script virtual module.

src/
├── client/
│	└── +script.ts
└── server/
	└── +func.ts

Virtual Modules

One challenging aspect of full-stack development and server-side rendering is managing the client files correctly during development and production. In development, you need to link directly to source files to benefit from features like TypeScript support and Hot Module Replacement (HMR). In production, the build process transforms each file and applies a hash to the filename for caching purposes.

domco takes care of these problems using virtual modules. You can easily serve a +page or include the tags for a +script in a response. domco ensures the correct assets are linked during development and in production.

client:page

You can import the transformed HTML of any +page.html from this module or one of it’s sub-paths. domco calls Vite’s transformIndexHtml hook on the imported page and inlines it into your server build.

// src/server/+func.ts
// returns transformed content of `src/client/+page.html`
import { html } from "client:page";
// `src/client/other/+page.html`
import { html as otherHtml } from "client:page/other";

export const handler = async (req: Request) => {
	return new Response(
		html, // bundled client application
		{
			headers: { "content-type": "text/html" },
		},
	);
};

client:script

You can also easily get the <script> tags for any +script module on the server as well. These script tags (including all imports) can be accessed via the client:script virtual module. They can be included in an HTML string, or inside of JSX.

In development, domco links the scripts to the source. In production, domco reads the manifest generated by the client build and includes the hashed version of these file names and their imports.

// src/server/+func.ts
// returns transformed content of `src/client/+script.ts`
import { tags } from "client:script";
// `src/client/other/+script.ts`
import { tags as otherTags } from "client:script/other";

export const handler = async (req: Request) => {
	return new Response(
		`<!doctype html>
		<html lang="en">
			<head>
				<meta charset="UTF-8" />
				<meta name="viewport" content="width=device-width, initial-scale=1.0" />
				${tags}
				<title>Document</title>
			</head>
			...
		</html>`,
		{
			headers: { "content-type": "text/html" },
		},
	);
};

Prerender

Export a prerender variable to prerender routes. prerender can be an array or set of paths to prerender, or a function that returns the paths.

// src/server/+func.ts
import type { Prerender } from "domco";

export const prerender: Prerender = [
	"/",
	"/post-1",
	"/post-2",
	"/some.css",
	"/some.json",
];

After the Vite build is complete, domco will import the handler from your function module and request the routes provided. The responses will be written to dist/client/(prerender-path) files upon build. If the path does not have an extension, /index.html will be added to the end of the file path to write.

For the export above, domco would request each path and generate the following files from the responses.

If you are using an adapter, these static files will be served in front of your request handler. So when an index.html file is found for the route, it is served directly without hitting your handler.

That’s It!

domco has a minimal API surface area and tries to get out of your way during development.

Next, learn how to deploy your application.