How to pass variable to render hook?

[marcuspollio]

In a theme using a custom image render hook, a srcset attribute of several resized images is used, along with its sizes attribute. It is quite handy to optimize resources and page loading.

Say some pages have content with full-width images, while some others have “blocks” with half-width images. Some logic to change the srcset and sizes attributes in the image render hook depending on the case (“block with half-width images” or no “block”) would be convenient, so images can be appropriately resized.

The theme has a custom content.html partial that sets some HTML semantics (like <section>, <article>) depending on the Markdown content, useful to style “blocks” among others. I’d like to reuse this separation code to pass a variable to the render hook, so srcset and sizes can be set appropriately.

I’ve tried to use the Store method (or Scratch) without success:
in partials/content.html:
{{/* If blocks */}} {{ .Store.Set "blocks" true }}
and then in _default/_markup/render-image.html:
{{- if .Store.Get "blocks" -}} {{/* Set srcset and sizes */}}

I would like to not use shortcodes. How would you approach this instead ? Thank you !

Local env

hugo v0.129.0-e85be29867d71e09ce48d293ad9d1f715bc09bb9 linux/amd64 BuildDate=2024-07-17T13:29:16Z VendorInfo=gohugoio
GOOS="linux"
GOARCH="amd64"
GOVERSION="go1.22.2"

[irkode]

the page in context is available via .Page

so .Page.Store should work. another option would be Markdown .Attributes in the .md file

Image render hooks

[marcuspollio]

Looks like it’s much easier than expected, with the right context.
Didn’t know about Parser Attributes.
Thank you !