Support implicit nesting

[WiserOrb]

TLDR: I would like an html attribute that is used as a prefix for any element in it's innerHTML.

I use jinja templates, and when i nest templates to build up a form (or replace some parts of it with HTMX) I need to pass the prefix for the json values down to the input.
However all the information is already in the html structure to infer the prefix. I would like to set the prefix on a container, then each input only specifies the last part. This makes it difficult to refactor/ make each request as local as possible.
I think this would pair very well with the whole hypermedia concept.

Example html where I use a fictional json-prefix attribute.

<form>
  <div json-prefix="car">
    <div json-previx="manufacturer">
      <input name="location">
      <input name="name">
    </div>
    <input name="model">
    <input name="plate">
  </div>
</form>

Resulting json. Observe how the various json-prefix compose with each other.

{
  "car": {
    "manufacturer": {
      "location": ...
      "name": ....
    },
    "model": ...
    "plate": ...
  }
}

Of course it would be nice to also have an opt-out flag to handle exceptions.

[xehrad]

This format doesn't suit your needs?

<form>
  <div>
    <div>
      <input name="car.manufacturer.location">
      <input name="car.manufacturer.name">
    </div>
    <input name="car.model">
    <input name="car.plate">
  </div>
</form>

[WiserOrb]

No, because the manufacturer fragment is not reusable in html templates.
If i want to put the same manufacturer inputs but under another form, now I need to pass to the manufacturer fragment the prefix required to build the json correctly.

For example if I want to input the a list of manufacturers (with the same structure) now I need a new template with just the prefix changed. This get's a bit hairy if that prefix changes dynamically based on user input.
Imagine an add manufacturer button, witch sends a htmx GET request and responds with the html fragment of the inputs.
This request is not usable in other forms unless I send the prefix every time.
This would allow to build unstructured trees of data with very little effort.

It's also less maintainable because if I want to move the manufacturer input under another name/location now I need to change the template (if it has a fixed prefix) or the tracking logic.