Support ESI/SSI includes

[timkelty]

Supporting Edge-side-includes would allow templates with dynamic content to still be cacheable.

[timkelty]

ESIs are now generally available for all Craft Cloud projects.
More details here: https://craftcms.com/blog/cloud-updates

[andrewfairlie]

We've got a project that could really benefit from ESI for performance. Is there any documentation for this?

[timkelty]

Nothing public yet, but plan on having something in next week or so.

FWIW, out implementation is RFC compliant with the ESI 1.0 spec, so there really isn't anything Craft or Craft Cloud specific here.

To make them easier to work with, we plan on providing a Twig tag that can fall back to regular include when not in a Craft Cloud environment (e.g. working locally).

I'll post some rough examples here today if you want to start playing around before we have official docs.