How to add a `\usepackage` in a Lua filter meant to support LaTeX?

How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[Norman Ramsey]

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I've got a Lua filter that is meant to render certain document elements in 
a `boxedminipage` environment.  To accomplish this feat, I give the element 
in a suitable `div`, and a Lua filter inserts the LaTeX environment.  The 
document itself remains universal, but the Lua filter is resolutely 
intended for LaTeX.

The filter adds a raw `\usepackage{boxedminipage2e}` to the 
`header-includes` of the metadata, but unfortunately when `-V 
header-includes=...` appears on the command line, it takes precedence and 
the document metadata is ignored.  

I thought of trying to use `-M header-includes=...` instead of `-V 
header-includes=...`, but that comes with its own problems: using the `-M` 
option, the argument on the command line is escaped.  It is not clear to me 
if there is a mechanism I can use to put raw LaTeX in that spot.

The issue of the command line overriding metadata has been discussed at 
some length on the issue tracker 
(https://github.com/jgm/pandoc/issues/3139) and in pandoc-discuss, where a 
related issue is laid out in the last post 
(https://groups.google.com/g/pandoc-discuss/c/N6WhlmSPXbY/m/UYJJBdZwAAAJ).
The discussion thread in pandoc-discuss is now two and a half years old, 
and it seemed to be in favor of a change. But as of pandoc version 
2.11.1.1, no change appears to have been made, and issue #3139 remains open.

Is there a workaround I can add to my Lua filter that will make it work in 
a self-contained way even in the presence of assignments to the 
`header-includes` variable on the command line?  And is there any thought 
of #3139 being resolved one way or the other?

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AW: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[denis.maier-FfwAq0itz3ofv37vnLkPlQ]

I don't know how that would work with a filter, but wouldn't a custom template be an easier solution? Or what speaks against this?

Best,
Denis


________________________________________
Von: pandoc-discuss-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org <pandoc-discuss-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org> im Auftrag von Norman Ramsey <fellswalker-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
Gesendet: Donnerstag, 19. November 2020 20:27:18
An: pandoc-discuss
Betreff: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

I've got a Lua filter that is meant to render certain document elements in a `boxedminipage` environment.  To accomplish this feat, I give the element in a suitable `div`, and a Lua filter inserts the LaTeX environment.  The document itself remains universal, but the Lua filter is resolutely intended for LaTeX.

The filter adds a raw `\usepackage{boxedminipage2e}` to the `header-includes` of the metadata, but unfortunately when `-V header-includes=...` appears on the command line, it takes precedence and the document metadata is ignored.

I thought of trying to use `-M header-includes=...` instead of `-V header-includes=...`, but that comes with its own problems: using the `-M` option, the argument on the command line is escaped.  It is not clear to me if there is a mechanism I can use to put raw LaTeX in that spot.

The issue of the command line overriding metadata has been discussed at some length on the issue tracker (https://github.com/jgm/pandoc/issues/3139) and in pandoc-discuss, where a related issue is laid out in the last post (https://groups.google.com/g/pandoc-discuss/c/N6WhlmSPXbY/m/UYJJBdZwAAAJ).
The discussion thread in pandoc-discuss is now two and a half years old, and it seemed to be in favor of a change. But as of pandoc version 2.11.1.1, no change appears to have been made, and issue #3139 remains open.

Is there a workaround I can add to my Lua filter that will make it work in a self-contained way even in the presence of assignments to the `header-includes` variable on the command line?  And is there any thought of #3139 being resolved one way or the other?

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Re: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[John MacFarlane]

You can always use a custom template.
Other than that, I'm not sure.  I see the need for this, and
need to think more about #3139 -- it's the kind of change
that might have unexpected consequences.

Norman Ramsey <fellswalker-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:

> I've got a Lua filter that is meant to render certain document elements in 
> a `boxedminipage` environment.  To accomplish this feat, I give the element 
> in a suitable `div`, and a Lua filter inserts the LaTeX environment.  The 
> document itself remains universal, but the Lua filter is resolutely 
> intended for LaTeX.
>
> The filter adds a raw `\usepackage{boxedminipage2e}` to the 
> `header-includes` of the metadata, but unfortunately when `-V 
> header-includes=...` appears on the command line, it takes precedence and 
> the document metadata is ignored.  
>
> I thought of trying to use `-M header-includes=...` instead of `-V 
> header-includes=...`, but that comes with its own problems: using the `-M` 
> option, the argument on the command line is escaped.  It is not clear to me 
> if there is a mechanism I can use to put raw LaTeX in that spot.
>
> The issue of the command line overriding metadata has been discussed at 
> some length on the issue tracker 
> (https://github.com/jgm/pandoc/issues/3139) and in pandoc-discuss, where a 
> related issue is laid out in the last post 
> (https://groups.google.com/g/pandoc-discuss/c/N6WhlmSPXbY/m/UYJJBdZwAAAJ).
> The discussion thread in pandoc-discuss is now two and a half years old, 
> and it seemed to be in favor of a change. But as of pandoc version 
> 2.11.1.1, no change appears to have been made, and issue #3139 remains open.
>
> Is there a workaround I can add to my Lua filter that will make it work in 
> a self-contained way even in the presence of assignments to the 
> `header-includes` variable on the command line?  And is there any thought 
> of #3139 being resolved one way or the other?
>
> -- 
> 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/2e27c210-a276-4319-abd7-c81d5db7f7d7n%40googlegroups.com.

Re: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[Norman Ramsey]

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I can work out a solution for my own personal use.  But other people are 
using my infrastructure.  Ideally I'd like to be able to tell them, "If you 
want this effect, use this filter."  Asking them also to use a custom 
template is not only a greater burden, but it's a solution that doesn't 
compose in the same way that filters do.  You can think of the problem I'm 
trying to solve like this: I want to extend Pandoc with a new capability.  
The capability is going to be supported by new markup, new CSS (for the 
HTML writer), and new LaTeX packages (for the LaTeX/PDF writer).  But I'm 
writing more than one extension, and I want my extensions to coexist 
peacefully with other extensions.  I can manage stuff like name-space 
collisions for element classes.  But a custom template become 
non-compositional.

One of the many issues I looked at today mentioned the idea of extending 
the standard template with a `filter-header-includes` variable, or even a 
`filter-header-includes.writer` variable.  As the OP in that thread 
observed, it's a bit clunky, but with discipline from filter authors, it 
could work.  The key would be this: filter authors would need to rely on 
and invariant saying that variable is not set on the command line. @jgm, 
I'm not sure whether you considered such an extension to the default 
templates?  (Pardon my poor memory, but I got deep into the weeds.)


On Thursday, November 19, 2020 at 2:50:51 PM UTC-5 denis...-FfwAq0itz3ofv37vnLkPlQ@public.gmane.org 
wrote:

> I don't know how that would work with a filter, but wouldn't a custom 
> template be an easier solution? Or what speaks against this?
>
> Best,
> Denis
>
>
> ________________________________________
> Von: pandoc-...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org <pandoc-...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org> im Auftrag 
> von Norman Ramsey <fells...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
> Gesendet: Donnerstag, 19. November 2020 20:27:18
> An: pandoc-discuss
> Betreff: How to add a `\usepackage` in a Lua filter meant to support LaTeX?
>
> I've got a Lua filter that is meant to render certain document elements in 
> a `boxedminipage` environment. To accomplish this feat, I give the element 
> in a suitable `div`, and a Lua filter inserts the LaTeX environment. The 
> document itself remains universal, but the Lua filter is resolutely 
> intended for LaTeX.
>
> The filter adds a raw `\usepackage{boxedminipage2e}` to the 
> `header-includes` of the metadata, but unfortunately when `-V 
> header-includes=...` appears on the command line, it takes precedence and 
> the document metadata is ignored.
>
> I thought of trying to use `-M header-includes=...` instead of `-V 
> header-includes=...`, but that comes with its own problems: using the `-M` 
> option, the argument on the command line is escaped. It is not clear to me 
> if there is a mechanism I can use to put raw LaTeX in that spot.
>
> The issue of the command line overriding metadata has been discussed at 
> some length on the issue tracker (
> https://github.com/jgm/pandoc/issues/3139) and in pandoc-discuss, where a 
> related issue is laid out in the last post (
> https://groups.google.com/g/pandoc-discuss/c/N6WhlmSPXbY/m/UYJJBdZwAAAJ).
> The discussion thread in pandoc-discuss is now two and a half years old, 
> and it seemed to be in favor of a change. But as of pandoc version 
> 2.11.1.1, no change appears to have been made, and issue #3139 remains open.
>
> Is there a workaround I can add to my Lua filter that will make it work in 
> a self-contained way even in the presence of assignments to the 
> `header-includes` variable on the command line? And is there any thought of 
> #3139 being resolved one way or the other?
>
> --
> 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-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org<mailto:
> pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org>.
> To view this discussion on the web visit 
> https://groups.google.com/d/msgid/pandoc-discuss/2e27c210-a276-4319-abd7-c81d5db7f7d7n%40googlegroups.com
> <
> https://groups.google.com/d/msgid/pandoc-discuss/2e27c210-a276-4319-abd7-c81d5db7f7d7n%40googlegroups.com?utm_medium=email&utm_source=footer
> >.
>

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Re: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[krulis....-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org]

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I totally agree with the question author: For my personal use I have highly 
customized LaTeX template. But actually for some projects I could go with 
only a little customizations like question author: Adding package in CLI 
and use filter to modify writer to write LaTeX source that uses the 
package. For some use-cases, this option could be very helpfull, if it 
would avoid collision with `header-includes` (that is sometimes "blocked" 
as writes question author). As mentioned, other formats could benefit from 
that as well.
Regards, Tomas

Dne čtvrtek 19. listopadu 2020 v 22:08:22 UTC+1 uživatel fells...@gmail.com 
napsal:

> I can work out a solution for my own personal use.  But other people are 
> using my infrastructure.  Ideally I'd like to be able to tell them, "If you 
> want this effect, use this filter."  Asking them also to use a custom 
> template is not only a greater burden, but it's a solution that doesn't 
> compose in the same way that filters do.  You can think of the problem I'm 
> trying to solve like this: I want to extend Pandoc with a new capability.  
> The capability is going to be supported by new markup, new CSS (for the 
> HTML writer), and new LaTeX packages (for the LaTeX/PDF writer).  But I'm 
> writing more than one extension, and I want my extensions to coexist 
> peacefully with other extensions.  I can manage stuff like name-space 
> collisions for element classes.  But a custom template become 
> non-compositional.
>
> One of the many issues I looked at today mentioned the idea of extending 
> the standard template with a `filter-header-includes` variable, or even a 
> `filter-header-includes.writer` variable.  As the OP in that thread 
> observed, it's a bit clunky, but with discipline from filter authors, it 
> could work.  The key would be this: filter authors would need to rely on 
> and invariant saying that variable is not set on the command line. @jgm, 
> I'm not sure whether you considered such an extension to the default 
> templates?  (Pardon my poor memory, but I got deep into the weeds.)
>
>
> On Thursday, November 19, 2020 at 2:50:51 PM UTC-5 denis...-FfwAq0itz3ofv37vnLkPlQ@public.gmane.org 
> wrote:
>
>> I don't know how that would work with a filter, but wouldn't a custom 
>> template be an easier solution? Or what speaks against this? 
>>
>> Best, 
>> Denis 
>>
>>
>> ________________________________________ 
>> Von: pandoc-...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org <pandoc-...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org> im 
>> Auftrag von Norman Ramsey <fells...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> 
>> Gesendet: Donnerstag, 19. November 2020 20:27:18 
>> An: pandoc-discuss 
>> Betreff: How to add a `\usepackage` in a Lua filter meant to support 
>> LaTeX? 
>>
>> I've got a Lua filter that is meant to render certain document elements 
>> in a `boxedminipage` environment. To accomplish this feat, I give the 
>> element in a suitable `div`, and a Lua filter inserts the LaTeX 
>> environment. The document itself remains universal, but the Lua filter is 
>> resolutely intended for LaTeX. 
>>
>> The filter adds a raw `\usepackage{boxedminipage2e}` to the 
>> `header-includes` of the metadata, but unfortunately when `-V 
>> header-includes=...` appears on the command line, it takes precedence and 
>> the document metadata is ignored. 
>>
>> I thought of trying to use `-M header-includes=...` instead of `-V 
>> header-includes=...`, but that comes with its own problems: using the `-M` 
>> option, the argument on the command line is escaped. It is not clear to me 
>> if there is a mechanism I can use to put raw LaTeX in that spot. 
>>
>> The issue of the command line overriding metadata has been discussed at 
>> some length on the issue tracker (
>> https://github.com/jgm/pandoc/issues/3139) and in pandoc-discuss, where 
>> a related issue is laid out in the last post (
>> https://groups.google.com/g/pandoc-discuss/c/N6WhlmSPXbY/m/UYJJBdZwAAAJ). 
>>
>> The discussion thread in pandoc-discuss is now two and a half years old, 
>> and it seemed to be in favor of a change. But as of pandoc version 
>> 2.11.1.1, no change appears to have been made, and issue #3139 remains 
>> open. 
>>
>> Is there a workaround I can add to my Lua filter that will make it work 
>> in a self-contained way even in the presence of assignments to the 
>> `header-includes` variable on the command line? And is there any thought of 
>> #3139 being resolved one way or the other? 
>>
>> -- 
>> 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-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org<mailto:
>> pandoc-discus...-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org>. 
>> To view this discussion on the web visit 
>> https://groups.google.com/d/msgid/pandoc-discuss/2e27c210-a276-4319-abd7-c81d5db7f7d7n%40googlegroups.com
>> <
>> https://groups.google.com/d/msgid/pandoc-discuss/2e27c210-a276-4319-abd7-c81d5db7f7d7n%40googlegroups.com?utm_medium=email&utm_source=footer>. 
>>
>>
>

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Re: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[BPJ]

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On 2020-11-19 20:27, Norman Ramsey wrote:
 > I've got a Lua filter that is meant to render certain document 
elements in
 > a `boxedminipage` environment.  To accomplish this feat, I give the 
element
 > in a suitable `div`, and a Lua filter inserts the LaTeX environment.  The
 > document itself remains universal, but the Lua filter is resolutely
 > intended for LaTeX.
 >
 > The filter adds a raw `\usepackage{boxedminipage2e}` to the
 > `header-includes` of the metadata, but unfortunately when `-V
 > header-includes=...` appears on the command line, it takes precedence and
 > the document metadata is ignored.

However you can, if the filter appends any includes done in
the filter to any existing meta.header-includes list combine it with
header-includes defined in a *metadata file* via
option --metadata-file=FILE or metadadata-files: in a defaults file
using the usual idiom:

`````````yaml
header-includes:
- |
   ````{=latex}
   \usepackage{relsize}
   ````
`````````

Alternatively you may even have a filter collect files and inject their 
contents
into the metadata header includes.

Two proof-of-concept filters attached:

1.  `inject-includes.lua` shows how you may inject includes dynamically in a
     filter, either creating the meta.header-includes list or appending 
them to
     an existing one.
2.  `inject-includes-files.lua` shows how you may inject the contents of 
a directory
     `header-includes` into the meta.header-includes list and thus get 
the best
     of both worlds! :-)

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[-- Attachment #2: inject-includes.lua --]
[-- Type: text/x-lua, Size: 2376 bytes --]

-- inject-includes.lua
-- A proof-of-concept Pandoc filter showing how you may create
-- header-includes from inside a filter.
--
-- NOTE: this only works if you do *not* use the -H/--include-in-header
-- option on the command line or include-in-header: in a defaults file.
-- However you can, since the filter appends any includes done in
-- the filter to any existing meta.header-includes list combine it with
-- header-includes defined in a *metadata file* via
-- option --metadata-file=FILE or metadadata-files: in a defaults file
-- using the usual idiom:
--
--    header-includes:
--    - |
--      ````{=latex}
--      \usepackage{relsize}
--      ````

local includes = pandoc.MetaList{}

local function inject_include (include, format)
  -- Fall back to the current output format as raw format
  -- NOTE: this is a bit risky if you do injects for multiple
  -- output formats in the same filter!
  format = format or FORMAT
  -- Do the actual header include injection
  includes[#includes+1] = pandoc.MetaBlocks{pandoc.RawBlock(format, include)}
end

-- If you know you are going to need certain header includes inject them here
inject_include(
  '\\usepackage[margins=raggedright]{floatrow}',
  'latex'
)

local function add_includes (meta)
  -- Get an alias so we don't need to type the long name
  local hinc = 'header-includes'
  if not meta[hinc] then
    meta[hinc] = includes
  else
    -- Make sure meta.header-includes is a MetaList
    -- or bail out if it is not.
    if 'table' ~= type(meta[hinc]) or 'MetaList' ~= meta[hinc].tag then
      error "Expected meta.header-includes to be list"
    end
    meta[hinc]:extend(includes)
  end
  return meta
end

-- If you need to inject includes dynamically do e.g. this:
local use_relsize = false
-- Reusable template.
-- We use `\textlarger` but text will be smaller if number is negative,
-- e.g. `\textlarger[-1]` == `\textsmaller[1]`!
local relsize_format = '\\textlarger[%d]'
local function do_relsize (span)
  local size = span.attributes.rs -- I like short class/attr names! :-)
  if not size then return nil end
  if not use_relsize then
    inject_include('\\usepackage{relsize}', 'latex')
    use_relsize = true
  end
  size = pandoc.RawInline('latex',relsize_format:format(size))
  return {size,span} -- curlies included by pandoc!
end

return {
  { Span = do_relsize },
  { Meta = add_includes },
}

[-- Attachment #3: inject-includes-files.lua --]
[-- Type: text/x-lua, Size: 3318 bytes --]

-- inject-includes.lua
-- A proof-of-concept Pandoc filter showing how you may collect
-- header-include files' contents and inject them into document
-- metadata from inside a filter.
--
-- This is useful if you want to both include metadata from files
-- *and* inject header-includes from filters, since if you use
-- the -H/--include-in-header option or `include-in-header:` in a
-- defaults file meta.header-includes will be ignored.
--
-- The workaround is to let a filter locate header-includes files
-- from a directory `header-includes` and/or files with names of
-- the form `header-include.EXT in the working directory
-- and inject their contents into meta.header-includes.
-- Pandoc's builtin mechanisms for header-includes files
-- must *not* be used!
--
-- Files are only included if their extension agrees with the
-- current output format. An extension agrees when it is
-- identical to pandoc's output format name or is included in
-- a table mapping extensions to "agreeing" formats.
-- See `local extension` in the filter code below.


local function qw (str,pat)
  pat = tostring(pat or '%S+')
  str = tostring(str)
  local lst = {}
  for s in str:gmatch(pat) do lst[#lst+1] = s end
  return lst
end

local function set (list)
  if 'table' ~= type(list) then list = qw(list) end
  local set = {}
  for _,v in ipairs(list) do set[v] = true end
  return set
end

local extension = {
  -- Maps extensions to formats which should have files
  -- with that extension included.
  ltx  = set"latex beamer",
  tex  = set"latex beamer",
  html = set"html html5 html4 epub", -- still more?
}

local function get_includes (format)
  -- Fall back to the current output format as raw format
  format = format or FORMAT
  local includes = pandoc.MetaList{}
  local includes_dirs = {
    { dir = '.',
      pat = '^header-include%.(%w+)$',
    },
    { dir = 'header-includes',
      pat = '^..-%.(%w+)$',
    },
  }
  for _,d in ipairs(includes_dirs) do
    -- Leave to Windows users to figure out how
    -- to do this on windows. pandoc.system.os
    -- could be consulted to determine the os
    local ls = pandoc.pipe("ls",{d.dir},"")
    -- Seems ls output is returned one line per item
    for _,f in ipairs(qw(ls,'[^\n]+')) do
      ext = f:match(d.pat)
      if ext
        and(extension[ext] and extension[ext][format])
        or(ext == format)
      then
        f = d.dir .. '/' .. f
        local handle = assert(
          io.open(f), "Couldn't open " .. f
        )
        local include = handle:read'a'
        handle:close()
        if "" ~= include then
          includes[#includes+1] = pandoc.MetaBlocks{
            pandoc.RawBlock(format, include)
          }
        end
      end
    end
  end
  if #includes > 0 then
    return includes
  end
  return nil
end


function Meta (meta)
  local includes = get_includes(FORMAT)
  if not includes then return nil end
  -- Get an alias so we don't need to type the long name
  local hinc = 'header-includes'
  if not meta[hinc] then
    meta[hinc] = includes
  else
    -- Make sure meta.header-includes is a MetaList
    -- or bail out if it is not.
    if 'table' ~= type(meta[hinc]) or 'MetaList' ~= meta[hinc].tag then
      error "Expected meta.header-includes to be list"
    end
    meta[hinc]:extend(includes)
  end
  return meta
end

Re: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[John MacFarlane]

Norman Ramsey <fellswalker-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes:

> I've got a Lua filter that is meant to render certain document elements in 
> a `boxedminipage` environment.  To accomplish this feat, I give the element 
> in a suitable `div`, and a Lua filter inserts the LaTeX environment.  The 
> document itself remains universal, but the Lua filter is resolutely 
> intended for LaTeX.
>
> The filter adds a raw `\usepackage{boxedminipage2e}` to the 
> `header-includes` of the metadata, but unfortunately when `-V 
> header-includes=...` appears on the command line, it takes precedence and 
> the document metadata is ignored.  
>
> I thought of trying to use `-M header-includes=...` instead of `-V 
> header-includes=...`, but that comes with its own problems: using the `-M` 
> option, the argument on the command line is escaped.  It is not clear to me 
> if there is a mechanism I can use to put raw LaTeX in that spot.

Why couldn't the filter add to the metadata `header-includes`
RawBlock (Format "latex") "\\usepackage{boxedminipage2e}"
?

Wouldn't that be a solution?

Re: How to add a `\usepackage` in a Lua filter meant to support LaTeX?

[Norman Ramsey]

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On Friday, November 20, 2020 at 2:44:01 PM UTC-5 John MacFarlane wrote:

> Norman Ramsey <fells...-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> writes: 
>
> > The filter adds a raw `\usepackage{boxedminipage2e}` to the 
> > `header-includes` of the metadata, but unfortunately when `-V 
> > header-includes=...` appears on the command line, it takes precedence 
> and 
> > the document metadata is ignored. 
>
>
> Why couldn't the filter add to the metadata `header-includes` 
> RawBlock (Format "latex") "\\usepackage{boxedminipage2e}" 
> ? 
>
> Wouldn't that be a solution? 
>

It’s a solution that works only some of the time. Unfortunately some of my 
clients have Makefiles that use the `-V` option to set the 
`header-includes` variable on the command line, and in that case the 
metadata `header-includes` is ignored. Hence my interest in open issue 
#3139 (if I am remembering the issue number correctly).

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