That is AWESOME - thank you!!!

I see that the function `function Span(span)` turns
    1 See on page #??.
in to
    1 See on page #2.
but I can't for the life of me figure out how.

Would you mind explaining that?

I've been digging through the docs, but got a lot of headscratching going 
on, many more questions than answers.
On Sunday, November 27, 2022 at 12:01:44 PM UTC-5 Bastien Dumont wrote:

> Please see the updated filter attached!
>
> Le Sunday 27 November 2022 à 08:24:43AM, user account a écrit :
> > Ok, gotcha! Could you point me to an example of how that page number 
> could be
> > printed somewhere?
> > 
> > My goal is this, HTML:
> > <p>Here's text with <a href="/some-blog-post">anchor text</a>.</p>
> > 
> > Becomes a paragraph in the pdf document:
> > Here's text with anchor text[1].
> > 
> > And then in the footer, is a footnote:
> > 1) See <scripted caption> one page #7.
> > 
> > ...where page 7 is the where the /some-blog-post is now located in this 
> pdf.
> > 
> > Does that make sense?
> > 
> > On Sunday, November 27, 2022 at 10:50:14 AM UTC-5 Bastien Dumont wrote:
> > 
> > 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 [1]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://
> > > [2]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?
> > > > > >
> > > > > > --
> > > > > > You received this message because you are subscribed to the 
> Google
> > > > Groups
> > > > > > "pandoc-discuss" group.
> > > > > > To unsubscribe from this group and stop receiving emails from it,
> > > send
> > > > an
> > > > > email
> > > > > > to [1]pandoc-discus...-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> > > > > > To view this discussion on the web visit [2][2][2]https://
> > > > [2][3]groups.google.com/
> > > > > d/msgid/
> > > > > > pandoc-discuss/a93afb43-c939-40c1-868f-1db8eded17d8n%[3]
> > > > > [3][3][4]40googlegroups.com.
> > > > > >
> > > > > > References:
> > > > > >
> > > > > > [1] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > > > > > [2] [4][4][4][5]
> https://groups.google.com/d/msgid/pandoc-discuss/
> > > > > a93afb43-c939-40c1-868f-1db8eded17d8n%[5][5][6]40googlegroups.com?
> > > utm_medium=
> > > > email&
> > > > > utm_source=footer
> > > > >
> > > > >
> > > > > --
> > > > > You received this message because you are subscribed to the Google
> > > Groups
> > > > > "pandoc-discuss" group.
> > > > > To unsubscribe from this group and stop receiving emails from it,
> > send
> > > an
> > > > email
> > > > > to [5]pandoc-discus...-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> > > > > To view this discussion on the web visit [6][6][6]https://
> > > [7]groups.google.com/
> > > > d/msgid/
> > > > > pandoc-discuss/2aec84ad-a750-48f2-a0c2-ad7572dcca11n%[7]
> > > > [7][8]40googlegroups.com.
> > > > >
> > > > > References:
> > > > >
> > > > > [1] [8][8][9]https://pandoc.org/
> > > > > [2] [9][9][10]https://groups.google.com/d/msgid/
> > > > > [3] [10][10][11]http://40googlegroups.com/
> > > > > [4] [11][11][12]https://groups.google.com/d/msgid/pandoc-discuss/
> > > > a93afb43-c939-40c1-868f-1db8eded17d8n%[12][13]40googlegroups.com?
> > utm_medium=
> > > email&
> > > > utm_source=footer
> > > > > [5] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > > > > [6] [12][13][14]https://groups.google.com/d/msgid/pandoc-discuss/
> > > > 2aec84ad-a750-48f2-a0c2-ad7572dcca11n%[14][15]40googlegroups.com?
> > utm_medium=
> > > email&
> > > > utm_source=footer
> > > >
> > > >
> > > > --
> > > > You received this message because you are subscribed to the Google
> > Groups
> > > > "pandoc-discuss" group.
> > > > To unsubscribe from this group and stop receiving emails from it, 
> send
> > an
> > > email
> > > > to [13]pandoc-discus...-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> > > > To view this discussion on the web visit [14][15]https://
> > > [16]groups.google.com/d/msgid/
> > > > pandoc-discuss/480d0274-2324-43d7-9f74-1bbfc08fcbd0n%[16]
> > > [17]40googlegroups.com.
> > > >
> > > > References:
> > > >
> > > > [1] [17][18]https://pandoc.org/
> > > > [2] [18][19]https://groups.google.com/
> > > > [3] [19][20]http://40googlegroups.com/
> > > > [4] [20][21]https://groups.google.com/d/msgid/pandoc-discuss/
> > > > [5] [21][22]http://40googlegroups.com/?utm_medium=email&
> > > > [6] [22][23]https://groups.google.com/d/msgid/
> > > > [7] [23][24]http://40googlegroups.com/
> > > > [8] [24][25]https://pandoc.org/
> > > > [9] [25][26]https://groups.google.com/d/msgid/
> > > > [10] [26][27]http://40googlegroups.com/
> > > > [11] [27][28]https://groups.google.com/d/msgid/pandoc-discuss/
> > > a93afb43-c939-40c1-868f-1db8eded17d8n%[29]
> 40googlegroups.com?utm_medium=
> > email&
> > > utm_source=footer
> > > > [12] [28][30]https://groups.google.com/d/msgid/pandoc-discuss/
> > > 2aec84ad-a750-48f2-a0c2-ad7572dcca11n%[31]
> 40googlegroups.com?utm_medium=
> > email&
> > > utm_source=footer
> > > > [13] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > > > [14] [29][32]https://groups.google.com/d/msgid/pandoc-discuss/
> > > 480d0274-2324-43d7-9f74-1bbfc08fcbd0n%[33]
> 40googlegroups.com?utm_medium=
> > email&
> > > utm_source=footer
> > >
> > >
> > > --
> > > You received this message because you are subscribed to the Google 
> Groups
> > > "pandoc-discuss" group.
> > > To unsubscribe from this group and stop receiving emails from it, send 
> an
> > email
> > > to [30]pandoc-discus...-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> > > To view this discussion on the web visit [31][34]https://
> > groups.google.com/d/msgid/
> > > pandoc-discuss/e969f1ca-c6bf-4a5e-b53f-86aa0a444db2n%[35]
> > 40googlegroups.com.
> > >
> > > References:
> > >
> > > [1] [36]https://pandoc.org/
> > > [2] [37]http://groups.google.com/
> > > [3] [38]http://40googlegroups.com/
> > > [4] [39]https://groups.google.com/d/msgid/pandoc-discuss/
> > > [5] [40]http://40googlegroups.com/?utm_medium=
> > > [6] [41]https://groups.google.com/
> > > [7] [42]http://40googlegroups.com/
> > > [8] [43]https://pandoc.org/
> > > [9] [44]https://groups.google.com/d/msgid/
> > > [10] [45]http://40googlegroups.com/
> > > [11] [46]https://groups.google.com/d/msgid/pandoc-discuss/
> > > [12] [47]http://40googlegroups.com/?utm_medium=email&
> > > [13] [48]https://groups.google.com/d/msgid/pandoc-discuss/
> > > [14] [49]http://40googlegroups.com/?utm_medium=email&
> > > [15] [50]https://groups.google.com/d/msgid/
> > > [16] [51]http://40googlegroups.com/
> > > [17] [52]https://pandoc.org/
> > > [18] [53]https://groups.google.com/
> > > [19] [54]http://40googlegroups.com/
> > > [20] [55]https://groups.google.com/d/msgid/pandoc-discuss/
> > > [21] [56]http://40googlegroups.com/?utm_medium=email&
> > > [22] [57]https://groups.google.com/d/msgid/
> > > [23] [58]http://40googlegroups.com/
> > > [24] [59]https://pandoc.org/
> > > [25] [60]https://groups.google.com/d/msgid/
> > > [26] [61]http://40googlegroups.com/
> > > [27] [62]https://groups.google.com/d/msgid/pandoc-discuss/
> > a93afb43-c939-40c1-868f-1db8eded17d8n%
> 40googlegroups.com?utm_medium=email&
> > utm_source=footer
> > > [28] [63]https://groups.google.com/d/msgid/pandoc-discuss/
> > 2aec84ad-a750-48f2-a0c2-ad7572dcca11n%
> 40googlegroups.com?utm_medium=email&
> > utm_source=footer
> > > [29] [64]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] [65]https://groups.google.com/d/msgid/pandoc-discuss/
> > e969f1ca-c6bf-4a5e-b53f-86aa0a444db2n%
> 40googlegroups.com?utm_medium=email&
> > utm_source=footer
> > 
> > 
> > --
> > You received this message because you are subscribed to the Google Groups
> > "pandoc-discuss" group.
> > To unsubscribe from this group and stop receiving emails from it, send 
> an email
> > to [66]pandoc-discus...-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
> > To view this discussion on the web visit [67]
> https://groups.google.com/d/msgid/
> > pandoc-discuss/858c5a07-89a0-4daa-803f-e0d9d50ca9c6n%40googlegroups.com.
> > 
> > References:
> > 
> > [1] https://pandoc.org/lua-filters.html#type-link
> > [2] http://pandoc.org/
> > [3] http://groups.google.com/
> > [4] http://40googlegroups.com/
> > [5] https://groups.google.com/d/msgid/pandoc-discuss/
> > [6] http://40googlegroups.com/
> > [7] http://groups.google.com/
> > [8] http://40googlegroups.com/
> > [9] https://pandoc.org/
> > [10] https://groups.google.com/d/msgid/
> > [11] http://40googlegroups.com/
> > [12] https://groups.google.com/d/msgid/pandoc-discuss/
> > [13] http://40googlegroups.com/?utm_medium=
> > [14] https://groups.google.com/d/msgid/pandoc-discuss/
> > [15] http://40googlegroups.com/?utm_medium=
> > [16] http://groups.google.com/d/msgid/
> > [17] http://40googlegroups.com/
> > [18] https://pandoc.org/
> > [19] https://groups.google.com/
> > [20] http://40googlegroups.com/
> > [21] https://groups.google.com/d/msgid/pandoc-discuss/
> > [22] http://40googlegroups.com/?utm_medium=email&
> > [23] https://groups.google.com/d/msgid/
> > [24] http://40googlegroups.com/
> > [25] https://pandoc.org/
> > [26] https://groups.google.com/d/msgid/
> > [27] http://40googlegroups.com/
> > [28] https://groups.google.com/d/msgid/pandoc-discuss/
> > [29] http://40googlegroups.com/?utm_medium=email&
> > [30] https://groups.google.com/d/msgid/pandoc-discuss/
> > [31] http://40googlegroups.com/?utm_medium=email&
> > [32] https://groups.google.com/d/msgid/pandoc-discuss/
> > [33] http://40googlegroups.com/?utm_medium=email&
> > [34] https://groups.google.com/d/msgid/
> > [35] http://40googlegroups.com/
> > [36] https://pandoc.org/
> > [37] http://groups.google.com/
> > [38] http://40googlegroups.com/
> > [39] https://groups.google.com/d/msgid/pandoc-discuss/
> > [40] http://40googlegroups.com/?utm_medium=
> > [41] https://groups.google.com/
> > [42] http://40googlegroups.com/
> > [43] https://pandoc.org/
> > [44] https://groups.google.com/d/msgid/
> > [45] http://40googlegroups.com/
> > [46] https://groups.google.com/d/msgid/pandoc-discuss/
> > [47] http://40googlegroups.com/?utm_medium=email&
> > [48] https://groups.google.com/d/msgid/pandoc-discuss/
> > [49] http://40googlegroups.com/?utm_medium=email&
> > [50] https://groups.google.com/d/msgid/
> > [51] http://40googlegroups.com/
> > [52] https://pandoc.org/
> > [53] https://groups.google.com/
> > [54] http://40googlegroups.com/
> > [55] https://groups.google.com/d/msgid/pandoc-discuss/
> > [56] http://40googlegroups.com/?utm_medium=email&
> > [57] https://groups.google.com/d/msgid/
> > [58] http://40googlegroups.com/
> > [59] https://pandoc.org/
> > [60] https://groups.google.com/d/msgid/
> > [61] http://40googlegroups.com/
> > [62] 
> https://groups.google.com/d/msgid/pandoc-discuss/a93afb43-c939-40c1-868f-1db8eded17d8n%40googlegroups.com?utm_medium=email&utm_source=footer
> > [63] 
> https://groups.google.com/d/msgid/pandoc-discuss/2aec84ad-a750-48f2-a0c2-ad7572dcca11n%40googlegroups.com?utm_medium=email&utm_source=footer
> > [64] 
> https://groups.google.com/d/msgid/pandoc-discuss/480d0274-2324-43d7-9f74-1bbfc08fcbd0n%40googlegroups.com?utm_medium=email&utm_source=footer
> > [65] 
> https://groups.google.com/d/msgid/pandoc-discuss/e969f1ca-c6bf-4a5e-b53f-86aa0a444db2n%40googlegroups.com?utm_medium=email&utm_source=footer
> > [66] mailto:pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org
> > [67] 
> https://groups.google.com/d/msgid/pandoc-discuss/858c5a07-89a0-4daa-803f-e0d9d50ca9c6n%40googlegroups.com?utm_medium=email&utm_source=footer
>
>

-- 
You received this message because you are subscribed to the Google Groups "pandoc-discuss" group.
To unsubscribe from this group and stop receiving emails from it, send an email to pandoc-discuss+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org
To view this discussion on the web visit https://groups.google.com/d/msgid/pandoc-discuss/80adcd1d-bc18-4b38-b3a9-0265d0922790n%40googlegroups.com.