How do I add a source or notes to figures and tables?

[Elayson]

I need to add notes to tables and figures, as shown in the image below.

A similar topic can be found in this post: How to add more fields to figure function? - #2 by quachpas, but I have additional requirements:

• The notes must match the width of the figure/table and be left-aligned;

• I need fields for notes, the source, and “footnotes” (like ᵃText, ᵇText) stacked vertically;

• Cross-referencing commands (e.g., <label>) must work normally;

• The entire structure must be unbreakable — meaning the title and notes should not be separated by a page break.

Ultimately, I need something like this:

#figure(
   image("image.png"),
   caption: [Title],
   source: [Text],
   note: [Text],
   footnote: [Text],
) <label>

Or whatever approach works best if the one above isn’t ideal.

I’ve tried redefining standard elements using something like #let default-figure = figure, but I’m not sure if that’s the correct way to do it, so I’d appreciate an explanation.

[gezepi]

Here’s a way to do it with a function that wraps around the normal figure function:

#let in-outline = state("in-outline", false)
#show outline: it => {
  in-outline.update(true)
  it
  in-outline.update(false)
}

#outline(target: figure)
#pagebreak()


#let figure(..args) = {
  let positional = args.pos()
  let named = args.named()

  //If the info is there, take it out to be combined later
  let source = if "source" in named { [Source: ] + named.remove("source") } else {none}
  let note = if "note" in named { [Note: ] + named.remove("note") } else {none}
  let caption = if "caption" in named { named.remove("caption") } else {none}

  //Combine the pieces of information
  let combined-caption = (source, note, caption).filter(p => p != none).join(linebreak())

  std.figure(
    ..named,
    ..positional,
    caption: context { if in-outline.get() {caption} else {combined-caption} }
  )
}

#figure(
  rect(stroke: 1pt)[figure content],
  supplement: [Rect],
  source: [Typst document],
  note: [A note about this figure],
  caption: [An important rectangle]
) <label>

See @label for more info.

Here the formatting of the extra pieces is just adding adding them on a new line. Putting all the pieces into a term list or a grid might be better options.