Optimize page data size and parsing (37% size reduction!)

[bram-pkg]

This PR adds support for the page data to be loaded from an app_page <script type="application/json"> element, this saves the SSR daemon quite a lot of type on big payloads because it not longer has to escape the HTML using " in the JSON.

It also saves a lot of page size on big payloads.

One of our pages with currently 343kb in props, went down to 219kb using this patch. That is a 37% reduction!

I have tested the changes using the SSR setup in the playgrounds. The changes are also backwards compatible, because the code gracefully falls back to using the data-page attribute.

In our profiler dump for the Node SSR process, escapeHtml takes up a non-insignificant of the profile with big payloads:

Inspired by my colleague @thomas-brx: #1960

Screenshots from the playgrounds working, note the app_page element:

Vue

Svelte

React

[bram-pkg]

@pascalbaljet it would be greatly appreciated if you could take a look at this and review, it would lead to a decent performance improvement for SSR and also a payload size reduction.

[pascalbaljet]

Awesome! I'll look into this soon.

[sinchijackal]

And if the TOON format https://github.com/toon-format/toon could be used, I think it would be even lighter.

[bram-pkg]

Seems unsuitable, they themselves say that non uniform and deeply nested JSON is more efficient if that is required, and since Inertia props tend to fall into those criteria, let's just stick with a native browser API. No need to overcomplicate things.

[pascalbaljet]

I'll refactor it a bit to put it behind a configuration flag. While it's backwards compatible, there's a possibility that people are relying on the data-page attribute in E2E and snapshot testing.

[bram-pkg]

That makes sense. Thanks! Looks good already.

[bram-pkg]

Do you need anything from me still, @pascalbaljet?

[pascalbaljet]

Do you need anything from me still, @pascalbaljet?

No, thanks! I'll work some more on this by adding tests, and then I'll merge it.