Expose isSamePage to turbo:visit events

#298 was a very welcome change, as now I can drop data: { turbo: !current_page?(thing_path) } from links that are anchors on the current page. However, turbo:visit events now fire for visits to anchors on the same page. I’m sure this is potentially useful in some ways, but for now, it’s meant that I’ve had to go from hooking into turbo:visit to using turbo:before-visit as follows:

import isEqual from "lodash.isequal"

document.addEventListener("turbo:before-visit", function (e) {
  const attributes = ({ origin, pathname }) => ({ origin, pathname })
  if (
    !isEqual(attributes(window.location), attributes(new URL(e.detail.url)))
  ) {
    // do things here
  }
})

What I’m doing there is pulling the origin (http://example.com) and the pathname (/blog, without an anchor or any query params) from the window location before the request is processed, and comparing it with those the target URL. If they’re identical, then it’s safe to say we shouldn’t do what would otherwise be triggered under turbo:visit.

It’d be nicer to be able to, for example, do this:

document.addEventListener("turbo:visit", function (e) {
  if(e.samePage) { return; }
  // do things here
})

[domchristie]

Latest builds are available here from https://github.com/hotwired/dev-builds/releases, so I think you could try:

yarn add https://github.com/hotwired/dev-builds/archive/refs/tags/@hotwired/turbo/latest.tar.gz

[domchristie]

Does seem a bit surprising for turbo:visit to fire if you’re staying on the same page?

I tend to agree. The same-page anchor system does use a Visit to do it’s thing, but the fired events do seem weird:

1. turbo:click
2. turbo:before-visit
3. turbo:visit
4. turbo:before-cache

This could lead to some odd situations, particularly if people are tearing down JavaScript behaviour on turbo:before-cache

I think same-page visits should be “silent” i.e. not fire turbo:before-visit, turbo:visit, or turbo:before-cache. This would also echo the behaviour that the native adapters take.