How can I create referrable labels for custom multi-level counters?

Questions
1

I have a custom counter and want to be able to attach a label whenever I step the counter. A popular solution in this forum is to create a figure with empty content and a custom kind, and then add a label to that figure. However, I can’t get this to work when my counter has two levels:

#let wpcounter = counter("wpcounter")

#wpcounter.step()
#context { wpcounter.display("1.1") }
#figure(kind: "wpcounter", supplement: "WP")[] <wp-a>

#wpcounter.step()
#context { wpcounter.display("1.1") }
#figure(kind: "wpcounter", supplement: "WP")[] <wp-b>

#wpcounter.step(level: 2)
#context { wpcounter.display("1.1") } 
#figure(kind: "wpcounter", supplement: "WP")[] <wp-c>

@wp-a

@wp-b

@wp-c

Screenshot 2025-04-04 at 11.25.11

Is this because the “wpcounter” kind creates its own counter that has nothing to do with my own counter called “wpcounter”? If yes, can someone give me a hint on how I would create a label that actually captures the state of my counter?

2

Indeed. The kind: "wpcounter" is for the counter(figure). Add this and see the result:

#figure[]

#context counter(figure).final()
#context counter(figure.where(kind: "wpcounter")).final()

I think that in certain situations using figure for this job is fine.

#let wpcounter = counter("wpcounter")

#let step-wpcounter(label, level: 1) = {
  wpcounter.step(level: level)
  context [wpcounter: #wpcounter.display("1.1")]
  [#figure(kind: "wpcounter", supplement: "WP")[]#label]
}

#show ref: it => {
  let target = query(it.target).first()
  if (
    type(target) != content
      or target.func() != figure
      or target.kind != "wpcounter"
  ) { return it }
  let sup = it.supplement
  if sup == auto { sup = target.supplement }
  let count = numbering("1.1", ..wpcounter.at(locate(it.target)))
  link(it.target)[#sup #count]
}

#step-wpcounter(<wp-a>)

#step-wpcounter(<wp-b>)

#step-wpcounter(<wp-c>, level: 2)

@wp-a

@wp-b

@wp-c

image

But ideally you shouldn’t use figures.

#let wpcounter = counter("wpcounter")

#let step-wpcounter(label, level: 1) = {
  wpcounter.step(level: level)
  context [wpcounter: #wpcounter.display("1.1")]
  [#metadata("wpcounter")#label]
}

#show ref: it => {
  let supplement = "WP"
  let target = query(it.target).first()
  if (
    type(target) != content
      or target.func() != metadata
      or target.value != "wpcounter"
  ) { return it }
  if it.supplement != auto { supplement = it.supplement }
  let count = numbering("1.1", ..wpcounter.at(locate(it.target)))
  link(it.target)[#sup #count]
}

Moreover, this is a solution where you manually create every label, which might be what you want. But if you want to create those labels automatically, then there is also a solution for this, but it depends on the counting system as here you only can have 26 labels.

Also, please, change the category to the appropriate Questions. You can also add some tags to allow people to narrow down their search.

1 Like
3

This is a very cool solution with the #metadata, thank you.

But while we’re at it, how can we set it up such that the ref to the WP label is still a reference, i.e. acts as a hyperlink in the PDF? Unless I missed something, the ref show rule now simply returns some unclickable text content.

1 Like
4

I suppose link(it.target)[#supplement #count] does the trick.

1 Like
5

Indeed. I guess I forgot about that part, since it wasn’t necessary for the output result.