Open it once, read it offline

ipe.rest keeps a small copy of itself in your browser, so a page you have already opened can open again with no connection. Here is how that works, and what it will not do.

Last time we listed what this site remembers about you, and one item was a cache of the site’s own files. This entry is about that cache: why it is there, how it behaves, and how to get rid of it.

What the home page sets up

When you open the home page, it registers a small program called a service worker. Your browser runs it in the background, apart from the page. Its job is simple: it sits between the site and the network and decides where each file should come from.

The first time it runs, it saves a short list of core files: the home pages, the journal index, the about, contact and privacy pages, the icons and the fonts. Everything else is saved later, as you read it.

Pages: the network comes first

For pages, the worker asks the network first, and it asks the server whether the page has changed instead of trusting an older copy held by the browser. When you are online you always get the current page, and a fresh copy goes into the cache each time.

If the network fails, the worker falls back to the copy it saved. So, if you have opened the home page in this browser, an entry you opened yesterday still opens today on a train with no signal. A page you never opened cannot be there, and in that case the worker shows the home page instead of a browser error.

Fonts, icons and styles: the cache comes first

Files that rarely change go the other way. The worker looks in the cache first and goes to the network only when it has no copy. That is why fonts and icons are not downloaded again on every visit.

How old copies go away

The cache has a version name, and we change it whenever the site’s files change. When a new version starts, the worker deletes every cache with a different name. Old copies do not pile up on your device, and a fix we publish reaches you on your next visit.

To remove everything yourself, clear the site’s data in your browser settings. The next visit starts from nothing.

What it does not do

The cache is a plain stash of files kept inside your browser. It is not a profile of you, and nothing in it is sent to us. It cannot show a page you never opened, and a link to another site, such as a track on YouTube, still needs a connection like anything else.

Why we bother

A journal about quiet things should not demand a perfect signal. People read in waiting rooms and on commutes, and a site that can open from a stash is kinder to those moments.

ipe(); // open it once, and it remembers how to open itself

If a page ever looks out of date, reload it once while you are online. The page itself is always asked for fresh; only files that rarely change, such as fonts, icons, styles, scripts and images, come from the stash, and they are renewed with each new version.