One form field - Multiple form elements?

I try to create a form field that I want to add a row with predefined form elements. I cannot use structure field this time because I don’t generate the rows on the fly. They are set in the blueprint.

How is that done? The only thing I could think of is to have a hidden textarea that is filled up with javascript from the other fields. Is that the only way?

I cannot get all form elements sent by this field with $_POST or something? Trusting JS feels a little unsafe with many rows of data.

I looked the web but could not find any good examples of it.

I try to do something like this with the Kirby Panel.

That’s why I need a field that is a row.

Looking at the structure field files of the upcoming 2.2, it looks like fields could define their own routes. That could really help you, right?

I don’t know how routes can work with fields but now I at least know what I can look for. Thanks!