How can I process citations using Pandoc's Citeproc, in Haskell? - haskell

Question

Starting with "A Simple Example" from the Pandoc documentation, I want to add citation processing functionality. The docs for Text.Pandoc.Citeproc show a function processCitations which supposedly processes citations. Yet given simple org-mode input, and a citation [#test2022], it doesn't seem to work. It compiles and runs just fine, but the output of the code below is: <p><span class="spurious-link" target="url"><em>testing</em></span> [#test2022]</p>, i.e., the citation isn't actually processed. What am I doing wrong? And how can I get this to process my citation?
import Text.Pandoc
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import Text.Pandoc.Filter
import Text.Pandoc.Citeproc
main :: IO ()
main = do
result <- runIO $ do
doc <- readOrg def (T.pack "#+bibliography: test.bib\n [[url][testing]]\n[#test2022]")
processed <- processCitations doc
writeHtml5String def processed
html <- handleError result
TIO.putStrLn html
For reference, here's my test.bib bibtex file:
#Book{test2022,
author = {Barus, Foobius},
title = {The Very Persistent Foo or Bar},
publisher = {Foobar Publications, Inc},
year = {2022}
}

Answer 1

I figured this out myself, eventually. Turns out you have to set some extensions, and some options, and set the metadata for the document:
{-# LANGUAGE OverloadedStrings #-}
import Text.Pandoc
import qualified Data.Text as T
import qualified Data.Text.IO as TIO
import Text.Pandoc.Filter
import Text.Pandoc.Citeproc
import qualified Data.Map as M
import Text.Pandoc.Builder (setMeta)
main :: IO ()
main = do
let exts = extensionsFromList [ Ext_citations ]
let readerOptions = def{ readerExtensions = exts}
let writerOptions = def{ writerExtensions = exts}
result <- runIO $ do
doc <- readMarkdown readerOptions (T.pack "Testing testing\n[#test2022]\n")
let doc' = setMeta (T.pack "bibliography") (T.pack "test.bib") doc :: Pandoc
processed <- processCitations doc'
writeHtml5String writerOptions processed
html <- handleError result
TIO.putStrLn html