Org Abstract Block Export

[biggs]

Is it possible to allow export of the abstract block, i.e.
#+BEGIN_ABSTRACT
as a pandoc_metadata 'abstract'? This would allow export of an abstract before the TOC in latex documents, which currently requires a long:
#+PANDOC_METADATA "abstract: very long line"

[tarleb]

Yes, this is possible, but requires some trickery. A simple way is to use a Lua filter: Put the following into a file and name it abstract-div-to-meta.lua. The file should either be in the same folder as your .org document, or in $HOME/.pandoc/filters/; the latter makes sense if you plan to re-use this technique with other documents.

-- file: abstract-div-to-meta.lua
local abstract = {}

function Div (div)
  if div.classes:includes 'ABSTRACT' then
    abstract = div.content
    return {}
  end
end

function Meta (meta)
  meta.abstract = pandoc.MetaBlocks(abstract)
  return meta
end

Now tell pandoc to use this by altering the variable org-pandoc-options. E.g., M-x (setq org-pandoc-options '((standalone . t) (lua-filter . "abstract-div-to-meta.lua"))). Your ABSTRACT block should now be converted into pandoc metadata on every export.

[biggs]

Thanks for the quick response, this does indeed seem to be the way to do it. However I'm currently getting an error with the LUA script:

Error occured. 
Error running filter abstract-div-to-meta.lua:
Error while running filter function: abstract-div-to-meta.lua:5: attempt to call a nil value (method 'includes')

Just to clarify, it runs without an abstract block, but not with one.

[biggs]

OK, I found a way to achieve more or less the desired functionality, using instead a top-level Abstract header:
https://github.com/pandoc/lua-filters/tree/master/abstract-to-meta

Thanks.

[tarleb]

Happy the other filter works for you.

The error is puzzling, includes exists since pandoc 2.0.4. Are you using an older version?

[biggs]

Ah - that does appear to be the issue, 2.0.2. Thanks!