Seems like Layouts CAN set HTTP response headers, contrary to the docs?
Nobody has claimed this yet.
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Description
📚 Subject area/topic
On-demand rendering, setting response headers in layouts
📋 Page(s) affected (or suggested, for new content)
https://docs.astro.build/en/guides/on-demand-rendering/#on-demand-rendering-features
📋 Description of content that is out-of-date or incorrect
On the on-demand rendering page, there is a big warning that HTTP headers cannot be modified inside layouts, only pages:
However, as far as I can tell, this isn't true?
Starting from npm create astro@latest and using the basic template:
/src/pages/index.astro:
---
import Welcome from '../components/Welcome.astro';
import Layout from '../layouts/Layout.astro';
Astro.response.headers.append('header-sources', '/pages/index.astro')
---
<Layout>
<Welcome />
</Layout>
/src/layouts/Layout.astro:
---
Astro.response.headers.append('header-sources', '/layouts/Layout.astro')
---
<!doctype html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta name="viewport" content="width=device-width" />
<link rel="icon" type="image/svg+xml" href="/favicon.svg" />
[...snipped...]
It seems like the layout DOES affect the final headers:
I'm not sure if this is a documentation error, or if there's some other way of setting headers that isn't supported, but Astro.response.headers() does work...? Or are there some edge cases in which it won't...?
🖥️ Reproduction in StackBlitz (if reporting incorrect content or code samples)
https://stackblitz.com/~/github.com/arcataroger/astro-header-modification-in-layout
Inside StackBlitz, I think you have to open the browser inspector and then reload the preview iframe:
Contributor guide
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
Research direction
Read the on-demand-rendering page section linked in the issue and reproduce the behavior with the provided StackBlitz example. Verify whether headers set in src/layouts/Layout.astro are consistently included in the final response, including any documented edge cases. Done means the warning is corrected or clarified based on the verified behavior.
Written by the indexing model from the issue text.
Assessment
- Domain
- documentation
- Issue type
- Documentation
- Difficulty
- 2/5
- Estimated time
- 1-3 hours
- Activity status
- Stale
- Clarity
- Mostly clear
- Newbie friendliness
- 42/100