# Static pages

> Pages written as files at build time (SSG), on Cloudflare.

On Cloudflare Workers, Fondu can write pages as static files at build time: static site generation (SSG). Workers
Static Assets serve them without running the Worker, and Inertia's visits keep working. This site is built that way.

```ts
// vite.config.ts
fondu({ target: 'cloudflare', prerender: true })
```

Static pages on Node and Bun are planned.

## Choosing the pages

A route opts in with `export const prerender`; a `_middleware.ts` sets it for its directory and below. The nearest
setting wins:

```ts
// app/routes/(marketing)/_middleware.ts: every page below
export const prerender = true

// app/routes/(marketing)/contact.ts: not this one
export const prerender = false

// app/routes/blog/[slug].ts: a dynamic route lists its pages' params
export const prerender = () => posts.map((post) => ({ slug: post.slug }))
```

`app/routes/_middleware.ts` with `export const prerender = true` makes every page static.

## How it works

Each page is written twice:

- as a document, `docs/intro.html`, for a first visit;
- as its page object, `_fondu/pages/docs/intro.json`, for Inertia's visits: Fondu's client reads it instead of asking
  the Worker.

The Worker still answers every other URL, a page that isn't static or one that doesn't exist. In development, it
answers all of them.

## What a static page can be

A static page is the same for everyone. It is rendered once, for a visitor with no cookies and no query string, shared
props included. So the build stops, naming the route, when a page:

- answers with a status other than 200, such as a redirect;
- takes POSTs at its URL (an `action`): Cloudflare answers those with 405 for a static file;
- uses deferred props or infinite scroll, which need the Worker.

## Headers

The pages' security headers, the Content Security Policy included, are written to `_headers`, which Cloudflare applies
to static files. The policy drops its nonce, as a static file can't have one: the document's scripts are the site's
own files.

## A new deploy

Each page records the build it belongs to. After a deploy, a visit from a tab opened before it reloads the page, as
Inertia does for a new version of the assets.