My filter only shows how one can inject raw code to get references by page number in LaTeX. Without any example, I don't really understand what you say about footnotes and so on, but the basic mechanism is here, now you can adapt the filter to your needs.

Le Sunday 27 November 2022 à 06:13:53AM, user account a écrit :
> oh a 'filters' subdir! Thanks. So now the pdf gets created w/o error, but there
> are not footnotes.
>
> neither of these:
> pandoc -L links-with-page-number.lua -o test.pdf test.html
> pandoc -V links-as-notes -L links-with-page-number.lua -o test.pdf
> test.html
> ...creates pdf w/ footnotes, so there's no footnote to contain the page number
> of the linked-to page.
>
> Something undesireable does happen though... I changed the paragraph with the
> link to:
> <p>Here is a link to <a href="#thetarget">important words about the target</a>.
> </p>
> ...and the "important words about the target" get removed altogether. Those
> should not be removed, just the <a> tags around them should be removed.
>
> Thanks for the help so far. I'm excited to see a lua filter in action for my
> first time. Very curious about the api... I presume pandoc is looking for
> functions with particular names like Link and Span? Would you mind
> confirming... this https://pandoc.org/lua-filters.html#type-link is the proper
> spot in the docs for referencing Link in this context... right?
>
> I imagine this working example produce footnotes w/ page numbers for you in
> your environment...? Any idea what I could inspect to try to get it working in
> mine?
> On Sunday, November 27, 2022 at 3:57:02 AM UTC-5 Bastien Dumont wrote:
>
> Place the file under `~/.local/share/pandoc/filters`. You don't need the
> executable flag.
>
> Le Saturday 26 November 2022 à 02:30:58PM, user account a écrit :
> > Thanks I wish that worked. I don't know what I'm doing wrong, here's what
> I've
> > got…
> >
> > `pandoc --version` says user data dir is `~/.local/share/pandoc` so I
> placed
> > this file there as `~/.local/share/pandoc/links-with-page-number.lua` and
> did
> > (just in case) `chmod +x` on it.
> >
> > `pandoc -o test.pdf test.html` produces a 2page pdf as expected with no
> > footnotes.
> >
> > `pandoc -L links-with-page-number.lua -o test.pdf test.html` fails to
> produce
> > pdf file with:
> > ```
> > Error running filter links-with-page-number.lua:
> > links-with-page-number.lua: openBinaryFile: does not exist (No such file
> or
> > directory)
> > ```
> >
> > There's no typo in my script name or command invocation. Using ~/.pandoc
> > instead of ~/.local/share/pandoc doesn't make any difference, still get
> that
> > same error.
> >
> > Any ideas?
> >
> > On Saturday, November 26, 2022 at 12:34:15 PM UTC-5 Bastien Dumont wrote:
> >
> > Please find attached a basic implementation. As in the attached sample
> HMTL
> > file, I suppose that the targets are marked with ids on spans and that
> you
> > link to it via empty <a> elements. If you have a LaTeX installation,
> simply
> > do `pandoc -L links-with-page-number.lua -o test.pdf test.html` to see
> the
> > result.
> >
> > Le Saturday 26 November 2022 à 05:21:25AM, user account a écrit :
> > > Thanks! Yeah injecting html in the intermediary document doesn't sound
> > very
> > > promising either (again, because the pages have to be built first
> before
> > > footnotes updated with page #s) so maybe I'll abandon weasyprint in
> this
> > case,
> > > if this would be easy to do with a *Tex pdf engine. In that case... how
> > would
> > > one go about this? Would a lua filter be more capable with a different
> > pdf
> > > engine or would a different mechanism be used?
> > >
> > > On Saturday, November 26, 2022 at 5:28:31 AM UTC-5 Bastien Dumont
> wrote:
> > >
> > > The problem is that Pandoc does not produce the PDF document: it
> produces
> > > the intermediary HTML document that is processed by weasyprint to
> produce
> > > the PDF. So you cannot get page numbers in a Lua filter.
> > >
> > > However, you can inject raw HTML code in the intermediary file (or in
> > your
> > > CSS) that will make weasyprint print the page numbers. The question is
> > > whether such HTML code exists. It certainly would be possible to do
> this
> > if
> > > you converted to PDF via LaTeX, ConTeXt or groff, but I don't know if
> it
> > is
> > > possible via weasyprint.
> > >
> > > Le Friday 25 November 2022 à 04:33:05PM, user account a écrit :
> > > > Using pandoc with weasyprint pdf engine to turn the markdown files
> from
> > a
> > > blog
> > > > (static site generator does the html conversion) into a pdf for
> print.
> > > >
> > > > Would it be possible, perhaps with a custom lua filter or some other
> > > mechanism,
> > > > to add the page number of the linked-to page? The page numbers won't
> be
> > > known
> > > > until pandoc has already created the document, and I don't know where
> > in
> > > 'the
> > > > pipeline' the lua filter intervenes compared to when the pages
> > exist...?
> > > And
> > > > If the pages exist with their numbers earlier enough, is there an
> > object
> > > or
> > > > something from which lua can get the page number?
> > > >
> > > > I haven't found anything about page numbers in [1][1][1]https://
> pandoc.org
> > /
> > > > lua-filters.html#module-pandoc.utils ...am I looking in the wrong
> > place?
> > > Can
> > > > anyone tell me anything about this?
> > > >
> > > > It's an intimidating rabbit hole for me, particularly because I see
> no
> > > mention
> > > > of "page number" there in the docs, which makes it seem kinda
> hopeless
> > > > actually. But maybe one of you know the way and could point me in
> that
> > > > direction?
> > > >
> > > > --
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> > an
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> > > > to [1]pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org.
> > > > To view this discussion on the web visit [2][2][2]https://
> > [2]groups.google.com/
> > > d/msgid/
> > > > pandoc-discuss/a93afb43-c939-40c1-868f-1db8eded17d8n%[3]
> > > [3][3]40googlegroups.com.
> > > >
> > > > References:
> > > >
> > > > [1] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > > > [2] [4][4][4]https://groups.google.com/d/msgid/pandoc-discuss/
> > > a93afb43-c939-40c1-868f-1db8eded17d8n%[5][5]40googlegroups.com?
> utm_medium=
> > email&
> > > utm_source=footer
> > >
> > >
> > > --
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> > > To view this discussion on the web visit [6][6][6]https://
> groups.google.com/
> > d/msgid/
> > > pandoc-discuss/2aec84ad-a750-48f2-a0c2-ad7572dcca11n%[7]
> > [7]40googlegroups.com.
> > >
> > > References:
> > >
> > > [1] [8][8]https://pandoc.org/
> > > [2] [9][9]https://groups.google.com/d/msgid/
> > > [3] [10][10]http://40googlegroups.com/
> > > [4] [11][11]https://groups.google.com/d/msgid/pandoc-discuss/
> > a93afb43-c939-40c1-868f-1db8eded17d8n%[12]40googlegroups.com?utm_medium=
> email&
> > utm_source=footer
> > > [5] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > > [6] [12][13]https://groups.google.com/d/msgid/pandoc-discuss/
> > 2aec84ad-a750-48f2-a0c2-ad7572dcca11n%[14]40googlegroups.com?utm_medium=
> email&
> > utm_source=footer
> >
> >
> > --
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> > to [13]pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org.
> > To view this discussion on the web visit [14][15]https://
> groups.google.com/d/msgid/
> > pandoc-discuss/480d0274-2324-43d7-9f74-1bbfc08fcbd0n%[16]
> 40googlegroups.com.
> >
> > References:
> >
> > [1] [17]https://pandoc.org/
> > [2] [18]https://groups.google.com/
> > [3] [19]http://40googlegroups.com/
> > [4] [20]https://groups.google.com/d/msgid/pandoc-discuss/
> > [5] [21]http://40googlegroups.com/?utm_medium=email&
> > [6] [22]https://groups.google.com/d/msgid/
> > [7] [23]http://40googlegroups.com/
> > [8] [24]https://pandoc.org/
> > [9] [25]https://groups.google.com/d/msgid/
> > [10] [26]http://40googlegroups.com/
> > [11] [27]https://groups.google.com/d/msgid/pandoc-discuss/
> a93afb43-c939-40c1-868f-1db8eded17d8n%40googlegroups.com?utm_medium=email&
> utm_source=footer
> > [12] [28]https://groups.google.com/d/msgid/pandoc-discuss/
> 2aec84ad-a750-48f2-a0c2-ad7572dcca11n%40googlegroups.com?utm_medium=email&
> utm_source=footer
> > [13] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > [14] [29]https://groups.google.com/d/msgid/pandoc-discuss/
> 480d0274-2324-43d7-9f74-1bbfc08fcbd0n%40googlegroups.com?utm_medium=email&
> utm_source=footer
>
>
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> To view this discussion on the web visit [31]https://groups.google.com/d/msgid/
> pandoc-discuss/e969f1ca-c6bf-4a5e-b53f-86aa0a444db2n%40googlegroups.com.
>
> References:
>
> [1] https://pandoc.org/
> [2] http://groups.google.com/
> [3] http://40googlegroups.com/
> [4] https://groups.google.com/d/msgid/pandoc-discuss/
> [5] http://40googlegroups.com/?utm_medium=
> [6] https://groups.google.com/
> [7] http://40googlegroups.com/
> [8] https://pandoc.org/
> [9] https://groups.google.com/d/msgid/
> [10] http://40googlegroups.com/
> [11] https://groups.google.com/d/msgid/pandoc-discuss/
> [12] http://40googlegroups.com/?utm_medium=email&
> [13] https://groups.google.com/d/msgid/pandoc-discuss/
> [14] http://40googlegroups.com/?utm_medium=email&
> [15] https://groups.google.com/d/msgid/
> [16] http://40googlegroups.com/
> [17] https://pandoc.org/
> [18] https://groups.google.com/
> [19] http://40googlegroups.com/
> [20] https://groups.google.com/d/msgid/pandoc-discuss/
> [21] http://40googlegroups.com/?utm_medium=email&
> [22] https://groups.google.com/d/msgid/
> [23] http://40googlegroups.com/
> [24] https://pandoc.org/
> [25] https://groups.google.com/d/msgid/
> [26] http://40googlegroups.com/
> [27] https://groups.google.com/d/msgid/pandoc-discuss/a93afb43-c939-40c1-868f-1db8eded17d8n%40googlegroups.com?utm_medium=email&utm_source=footer
> [28] https://groups.google.com/d/msgid/pandoc-discuss/2aec84ad-a750-48f2-a0c2-ad7572dcca11n%40googlegroups.com?utm_medium=email&utm_source=footer
> [29] https://groups.google.com/d/msgid/pandoc-discuss/480d0274-2324-43d7-9f74-1bbfc08fcbd0n%40googlegroups.com?utm_medium=email&utm_source=footer
> [30] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> [31] https://groups.google.com/d/msgid/pandoc-discuss/e969f1ca-c6bf-4a5e-b53f-86aa0a444db2n%40googlegroups.com?utm_medium=email&utm_source=footer