Support for 103 Early Hints?

[proimage]

Is this something that can be implemented already, using something like this?

{% set headerResponse -%}
HTTP/1.1 103 Early Hints
	Link: <{{ mix('css/site.css') }}>; as=style; rel=preload
	Link: <{{ mix('js/site.js') }}>; as=script; rel=preload
	Link: <{{ entry.heroImage.one().url() }}>; as=image; rel=preload
{%- endset %}
{% header headerResponse %}

Or does Yii need to explicitly add support for the 103 response?

[brandonkelly]

This isn’t currently possible out of the box, because your entire template output is captured by an output buffer until rendering is complete. (Otherwise you would get a PHP error about headers already being sent every time you try putting a {% header %} tag in your templates.)

That said, it should be possible for us to add some support for this at the infrastructure level within Craft Cloud, and for other hosts. We’ll look into it.

[proimage]

Thanks, BK!