Replace repository Pandoc plugin

Replace the repository Pandoc plugin *pandoc.pm* in preference for
that of Fripost ansible repository
<https://git.fripost.org/fripost-ansible>. Path */roles/wiki/files/var/lib/ikiwiki/IkiWiki/Plugin/pandoc.pm*

1 files changed, 555 insertions, 103 deletions

diff --git a/.ikiwiki/IkiWiki/Plugin/pandoc.pm b/.ikiwiki/IkiWiki/Plugin/pandoc.pm
index ddc5299..25081ef 100755
--- a/.ikiwiki/IkiWiki/Plugin/pandoc.pm
+++ b/.ikiwiki/IkiWiki/Plugin/pandoc.pm
@@ -7,8 +7,20 @@ use strict;
 use IkiWiki;
 use FileHandle;
 use IPC::Open2;
+use File::Path qw/make_path/;
 use JSON;
 
+# activate with 'generate_$format' in meta; turn on all with 'generate_all_formats'.
+my %extra_formats = (
+    pdf    => { ext=>'pdf', label=>'PDF', format=>'latex', extra=>[], order=>1 },
+    docx   => { ext=>'docx', label=>'DOCX', format=>'docx', extra=>[], order=>2 },
+    odt    => { ext=>'odt', label=>'ODT', format=>'odt', extra=>[], order=>3 },
+    beamer => { ext=>'beamer.pdf', label=>'Beamer', format=>'beamer', extra=>[], order=>4 },
+    revealjs => { ext=>'revealjs.html', label=>'RevealJS', format=>'revealjs', extra=>['--self-contained'], order=>5 },
+    epub   => { ext=>'epub', label=>'EPUB', format=>'epub3', extra=>[], order=>6 },
+    latex  => { ext=>'tex', label=>'LaTeX', format=>'latex', extra=>['--standalone'], order=>7 },
+);
+
 sub import {
     my $markdown_ext = $config{pandoc_markdown_ext} || "mdwn";
 
@@ -18,6 +30,9 @@ sub import {
     }
 
     hook(type => "getsetup", id => "pandoc", call => \&getsetup);
+    hook(type => "pagetemplate", id => "pandoc", call => \&pagetemplate);
+    hook(type => "pageactions", id => "pandoc", call => \&pageactions);
+
     if (ref $markdown_ext eq 'ARRAY') {
         foreach my $mde (@$markdown_ext) {
             hook(type => 'htmlize', id => $mde,
@@ -43,6 +58,14 @@ sub import {
         hook(type => "htmlize", id => "mediawiki",
              call => sub { htmlize("mediawiki", @_) });
     }
+    if ($config{pandoc_opml}) {
+        hook(type => "htmlize", id => "opml",
+             call => sub { htmlize("opml", @_) });
+    }
+    if ($config{pandoc_org}) {
+        hook(type => "htmlize", id => "org",
+             call => sub { htmlize("org", @_) });
+    }
 }
 
 
@@ -56,42 +79,63 @@ sub getsetup () {
         type => "string",
         example => "/usr/local/bin/pandoc",
         description => "Path to pandoc executable",
-        safe => 0,
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_citeproc => {
+        type => "string",
+        example => "/usr/local/bin/pandoc-citeproc",
+        description => "Path to pandoc-citeproc executable",
+        safe => 1,
         rebuild => 0,
     },
     pandoc_markdown_ext => {
         type => "string",
-        example => "mdwn",
-        description => "File extension for Markdown files",
+        example => "mdwn,md,markdown",
+        description => "File extension(s) for Markdown files handled by Pandoc",
         safe => 1,
         rebuild => 1,
     },
     pandoc_latex => {
         type => "boolean",
         example => 0,
-        description => "Enable Pandoc processing of LaTeX documents",
-        safe => 0,
+        description => "Enable Pandoc processing of LaTeX documents (extension=tex)",
+        safe => 1,
         rebuild => 1,
     },
     pandoc_rst => {
         type => "boolean",
         example => 0,
-        description => "Enable Pandoc processing of reStructuredText documents",
-        safe => 0,
+        description => "Enable Pandoc processing of reStructuredText documents (extension=rst)",
+        safe => 1,
         rebuild => 1,
     },
     pandoc_textile => {
         type => "boolean",
         example => 0,
-        description => "Enable Pandoc processing of Textile documents",
-        safe => 0,
+        description => "Enable Pandoc processing of Textile documents (extension=textile)",
+        safe => 1,
         rebuild => 1,
     },
     pandoc_mediawiki => {
         type => "boolean",
         example => 0,
-        description => "Enable Pandoc processing of MediaWiki documents",
-        safe => 0,
+        description => "Enable Pandoc processing of MediaWiki documents (extension=mediawiki)",
+        safe => 1,
+        rebuild => 1,
+    },
+    pandoc_org => {
+        type => "boolean",
+        example => 0,
+        description => "Enable Pandoc processing of Emacs org-mode documents (extension=org)",
+        safe => 1,
+        rebuild => 1,
+    },
+    pandoc_opml => {
+        type => "boolean",
+        example => 0,
+        description => "Enable Pandoc processing of OPML documents (extension=opml)",
+        safe => 1,
         rebuild => 1,
     },
     pandoc_smart => {
@@ -122,6 +166,13 @@ sub getsetup () {
         safe => 1,
         rebuild => 1,
     },
+    pandoc_html_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for html",
+        safe => 0,
+        rebuild => 0,
+    },
     pandoc_numsect => {
         type => "boolean",
         example => 0,
@@ -146,24 +197,143 @@ sub getsetup () {
     pandoc_math => {
         type => "string",
         example => "mathjax",
-        description => "Process TeX math using",
-        safe => 0,
+        description => "How to process TeX math (mathjax, katex, mathml, mathjs, latexmathml, asciimathml, mimetex, webtex)",
+        safe => 1,
+        rebuild => 1,
+    },
+    pandoc_math_custom_js => {
+        type => "string",
+        example => "",
+        description => "Link to local/custom javascript for math (or to server-side script for mimetex and webtex)",
+        safe => 1,
+        rebuild => 1,
+    },
+    pandoc_math_custom_css => {
+        type => "string",
+        example => "",
+        description => "Link to local/custom CSS for math (requires appropriate pandoc_math setting)",
+        safe => 1,
         rebuild => 1,
     },
     pandoc_bibliography => {
         type => "string",
         example => "",
-        description => "Path to bibliography file",
-        safe => 0,
+        description => "Path to default bibliography file",
+        safe => 1,
         rebuild => 1,
     },
     pandoc_csl => {
         type => "string",
         example => "",
         description => "Path to CSL file (for references and bibliography)",
-        safe => 0,
+        safe => 1,
+        rebuild => 1,
+    },
+    pandoc_csl_default_lang => {
+        type => "string",
+        example => "",
+        description => "Default language code (RFC 1766) for citations processing",
+        safe => 1,
         rebuild => 1,
     },
+    pandoc_filters => {
+        type => "string",
+        example => "",
+        description => "A comma-separated list of custom pandoc filters",
+        safe => 1,
+        rebuild => 1,
+    },
+    pandoc_latex_template => {
+        type => "string",
+        example => "",
+        description => "Path to pandoc template for LaTeX and normal PDF output",
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_latex_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for LaTeX (and PDF) generation",
+        safe => 0,
+        rebuild => 0,
+    },
+    pandoc_beamer_template => {
+        type => "string",
+        example => "",
+        description => "Path to pandoc template for Beamer PDF output",
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_beamer_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for Beamer PDF generation",
+        safe => 0,
+        rebuild => 0,
+    },
+    pandoc_pdf_export_cleanup => {
+        type => "boolean",
+        example => "0",
+        description => "Whether to clean up LaTeX auxiliary files after PDF generation",
+        safe => 0,
+        rebuild => 0,
+    },
+    pandoc_revealjs_template => {
+        type => "string",
+        example => "",
+        description => "Path to pandoc template for Reveal.js slides output",
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_revealjs_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for Reveal.js slides generation",
+        safe => 0,
+        rebuild => 0,
+    },
+    pandoc_docx_template => {
+        type => "string",
+        example => "",
+        description => "Path to pandoc template for MS Word (docx) output",
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_docx_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for DOCX generation",
+        safe => 0,
+        rebuild => 0,
+    },
+    pandoc_odt_template => {
+        type => "string",
+        example => "",
+        description => "Path to pandoc template for OpenDocument (odt) output",
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_odt_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for ODT generation",
+        safe => 0,
+        rebuild => 0,
+    },
+    pandoc_epub_template => {
+        type => "string",
+        example => "",
+        description => "Path to pandoc template for EPUB3 output",
+        safe => 1,
+        rebuild => 0,
+    },
+    pandoc_epub_extra_options => {
+        type => "internal",
+        default => [],
+        description => "List of extra pandoc options for EPUB3 generation",
+        safe => 0,
+        rebuild => 0,
+    };
 }
 
 
@@ -171,96 +341,88 @@ sub htmlize ($@) {
     my $format = shift;
     my %params = @_;
     my $page = $params{page};
+    my $htmlformat = 'html';
 
     local(*PANDOC_IN, *JSON_IN, *JSON_OUT, *PANDOC_OUT);
-    my @args;
+    my @args = ();
 
-    my $command = $config{pandoc_command} || "/usr/local/bin/pandoc";
+    # The default assumes pandoc is in PATH
+    my $command = $config{pandoc_command} || "pandoc";
 
     if ($config{pandoc_smart}) {
         push @args, '--smart';
-    };
+    }
 
     if ($config{pandoc_obfuscate}) {
         push @args, '--email-obfuscation=references';
     } else {
         push @args, '--email-obfuscation=none';
-    };
+    }
 
     if ($config{pandoc_html5}) {
-        push @args, '--html5';
-    };
+        $htmlformat = 'html5';
+    }
 
     if ($config{pandoc_ascii}) {
         push @args, '--ascii';
-    };
+    }
 
     if ($config{pandoc_numsect}) {
         push @args, '--number-sections';
-    };
+    }
 
     if ($config{pandoc_sectdiv}) {
         push @args, '--section-divs';
-    };
+    }
 
     if ($config{pandoc_codeclasses} && ($config{pandoc_codeclasses} ne "")) {
         push @args, '--indented-code-classes=' . $config{pandoc_codeclasses};
-    };
-
-    if ($config{pandoc_bibliography}) {
-        push @args, '--bibliography='.$config{pandoc_bibliography};
     }
 
-    if ($config{pandoc_csl}) {
-        push @args, '--csl='.$config{pandoc_csl};
-    }
-
-    for ($config{pandoc_math}) {
-        if (/^mathjax$/) {
-            push @args, '--mathjax=/dev/null';
-        }
-        elsif (/^jsmath$/) {
-            push @args, '--jsmath';
-        }
-        elsif (/^latexmathml$/) {
-            push @args, '--latexmathml';
-        }
-        elsif (/^mimetex$/) {
-            push @args, '--mimetex';
-        }
-        elsif (/^mathtex$/) {
-            push @args, '--mimetex=/cgi-bin/mathtex.cgi';
+    # How to process math. Normally either mathjax or katex.
+    my %mathconf = map {($_=>"--$_")} qw(
+        jsmath mathjax latexmathml asciimathml mathml katex mimetex webtex
+    );
+    my %with_urls = qw/mimetex 1 webtex 1/;
+    my $mathopt = $1 if $config{pandoc_math} && $config{pandoc_math} =~ /(\w+)/;
+    my $custom_js = $config{pandoc_math_custom_js} || '';
+    # cleanup pandoc-prefixed keys from persistent meta
+    if (ref $pagestate{$page}{meta} eq 'HASH') {
+        my @delkeys = ();
+        foreach my $k (%{ $pagestate{$page}{meta} }) {
+            push @delkeys, $k if $k =~ /^pandoc_/;
         }
-        elsif (/^google$/) {
-            push @args, '--webtex';
-        }
-        elsif (/^mathml$/) {
-            push @args, '--mathml';
+        delete $pagestate{$page}{meta}{$_} for @delkeys;
+    }
+    if ($mathopt && $mathconf{$mathopt}) {
+        if ($with_urls{$mathopt} && $custom_js) {
+            # In these cases, the 'custom js' is a misnomer: actually a server-side script
+            push @args, $mathconf{$mathopt} ."=". $custom_js;
+        } else {
+            push @args, $mathconf{$mathopt};
         }
-        else { }
+        $pagestate{$page}{meta}{"pandoc_math"} = $mathopt;
+        $pagestate{$page}{meta}{"pandoc_math_$mathopt"} = 1;
+        $pagestate{$page}{meta}{"pandoc_math_custom_js"} = $custom_js if $custom_js;
     }
-
     # Convert to intermediate JSON format so that the title block
     # can be parsed out
+    # We must omit the 'bibliography' parameter here, otherwise the list of
+    # references will be doubled.
     my $to_json_pid = open2(*JSON_OUT, *PANDOC_OUT, $command,
                     '-f', $format,
                     '-t', 'json',
-                    @args);
-
+                    @args, '--normalize');
     error("Unable to open $command") unless $to_json_pid;
 
-    # $ENV{"LC_ALL"} = "en_US.UTF-8";
-    my $to_html_pid = open2(*PANDOC_IN, *JSON_IN, $command,
-                    '-f', 'json',
-                    '-t', 'html',
-                    @args);
-
-    error("Unable to open $command") unless $to_html_pid;
-
     # Workaround for perl bug (#376329)
     require Encode;
     my $content = Encode::encode_utf8($params{content});
 
+    # Protect inline plugin placeholders from being mangled by pandoc:
+    $content =~ s{<div class="inline" id="(\d+)"></div>}
+                 {::INLINE::PLACEHOLDER::$1::}g;
+
     print PANDOC_OUT $content;
     close PANDOC_OUT;
 
@@ -269,6 +431,148 @@ sub htmlize ($@) {
 
     waitpid $to_json_pid, 0;
 
+    # Parse the title block out of the JSON and set the meta values
+    my $meta = undef;
+    my $decoded_json = decode_json($json_content);
+    # The representation of the meta block changed in pandoc version 1.18
+    if (ref $decoded_json eq 'HASH' && $decoded_json->{'Meta'}) {
+        $meta = $decoded_json->{'Meta'} || {}; # post-1.18 version
+    } elsif (ref $decoded_json eq 'ARRAY') {
+        $meta = $decoded_json->[0]->{'unMeta'} || {}; # pre-1.18 version
+    }
+    unless ($meta) {
+        warn "WARNING: Unexpected format for meta block. Incompatible version of Pandoc?\n";
+    }
+
+    # Get some selected meta attributes, more specifically:
+    # (title date bibliography csl subtitle abstract summary description
+    #  version lang  locale references author [+ num_authors primary_author]),
+    # as well as some configuration options (generate_*, *_extra_options, *_template).
+
+    my @format_keys = grep { $_ ne 'pdf' } keys %extra_formats;
+    my %scalar_meta = map { ($_=>undef) } qw(
+        title date bibliography csl subtitle abstract summary
+        description version lang locale);
+    $scalar_meta{$_.'_template'} = undef for @format_keys;
+    my %bool_meta = map { ("generate_$_"=>0) } keys %extra_formats;
+    my %list_meta = map { ($_=>[]) } qw/author references/;
+    $list_meta{$_.'_extra_options'} = [] for @format_keys;
+    my $have_bibl = 0;
+    foreach my $k (keys %scalar_meta) {
+        next unless $meta->{$k};
+        $scalar_meta{$k} = compile_string($meta->{$k}->{c});
+        # NB! Note that this is potentially risky, since pagestate is sticky, and
+        # we only cleanup the pandoc_* values in {meta}.
+        $pagestate{$page}{meta}{$k} = $scalar_meta{$k};
+        $pagestate{$page}{meta}{"pandoc_$k"} = $pagestate{$page}{meta}{$k};
+    }
+    foreach my $k (keys %bool_meta) {
+        my $gen_all = $meta->{generate_all_formats} || {};
+        next unless $meta->{$k} || $gen_all->{c};
+        my $val = $meta->{$k} ? $meta->{$k}->{c} : $gen_all->{c};
+        # simplifies matters with JSON::(PP::)Boolean objects
+        $val = 1 if $val == 1 || $val eq 'true';
+        if (ref $val || $val =~ /^\s*(?:off|no|false|0)\s*$/i) {
+            $bool_meta{$k} = 0;
+        } else {
+            $bool_meta{$k} = 1;
+            $pagestate{$page}{meta}{"pandoc_$k"} = 1;
+        }
+    }
+    foreach my $k (keys %list_meta) {
+        next unless $meta->{$k};
+        $list_meta{$k} = unwrap_c($meta->{$k});
+        $list_meta{$k} = [$list_meta{$k}] unless ref $list_meta{$k} eq 'ARRAY';
+        $have_bibl = 1 if $k eq 'references';
+        $pagestate{$page}{meta}{"pandoc_$k"} = $list_meta{$k};
+    }
+    # Try to add other keys as scalars, with pandoc_ prefix only.
+    foreach my $k (keys %$meta) {
+        next if exists $scalar_meta{$k} || exists $list_meta{$k};
+        eval {
+            $pagestate{$page}{meta}{"pandoc_$k"} = compile_string($meta->{$k}->{c});
+        };
+    }
+    my $num_authors = scalar @{ $list_meta{author} };
+    $scalar_meta{num_authors} = $num_authors;
+    $pagestate{$page}{meta}{num_authors} = $num_authors;
+    if ($num_authors) {
+        $scalar_meta{primary_author} = $list_meta{author}->[0];
+        $pagestate{$page}{meta}{author} = join(', ', @{$list_meta{author}});
+        $pagestate{$page}{meta}{pandoc_primary_author} = $scalar_meta{primary_author}
+    }
+
+    # The bibliography may be set in a Meta block in the page or in the .setup file.
+    # If both are present, the Meta block has precedence.
+    for my $bibl ($scalar_meta{bibliography}, $config{pandoc_bibliography}) {
+        if ($bibl) {
+            $have_bibl = 1;
+            $pagestate{$page}{meta}{pandoc_bibliography} = $bibl;
+            push @args, '--bibliography='.$bibl;
+            last;
+        }
+    }
+    # Similarly for the CSL file...
+    for my $cslfile ($scalar_meta{csl}, $config{pandoc_csl}) {
+        if ($cslfile) {
+            $pagestate{$page}{meta}{pandoc_csl} = $cslfile;
+            push @args, '--csl='.$cslfile;
+            last;
+        }
+    }
+    # If a default CSL language is specified, add that to args,
+    # (unless it is overridden by meta)
+    unless ($scalar_meta{lang} || $scalar_meta{locale}) {
+        if ($config{pandoc_csl_default_lang}) {
+            push @args, "--metadata=lang:".$config{pandoc_csl_default_lang};
+        }
+    }
+    # Turn on the pandoc-citeproc filter if either global bibliography,
+    # local bibliography or a 'references' key in Meta is present.
+    if ($have_bibl) {
+        my $citeproc = $config{pandoc_citeproc} || 'pandoc-citeproc';
+        push @args, "--filter=$citeproc";
+    }
+
+    # Other pandoc filters. Note that currently there is no way to
+    # configure a filter to run before pandoc-citeproc has done its work.
+    if ($config{pandoc_filters}) {
+        my @filters = split /\s*,\s*/, $config{pandoc_filters};
+        s/^["']//g for @filters; # get rid of enclosing quotes
+        foreach my $filter (@filters) {
+            push @args, "--filter=$filter";
+        }
+    }
+
+    # html_extra_options my be set in Meta block in the page or in the .setup
+    # file.  If both are present, the Meta block has precedence, even if it is
+    # an empty list
+    my @html_args = @args;
+    if (ref $meta->{html_extra_options}{c} eq 'ARRAY') {
+      if (ref unwrap_c($meta->{html_extra_options}{c}) eq 'ARRAY') {
+        push @html_args, @{unwrap_c($meta->{html_extra_options}{c})};
+      } else {
+        push @html_args, unwrap_c($meta->{html_extra_options}{c});
+      }
+    } elsif (ref $config{'pandoc_html_extra_options'} eq 'ARRAY') {
+      push @html_args, @{$config{'pandoc_html_extra_options'}};
+    }
+
+    my $to_html_pid = open2(*PANDOC_IN, *JSON_IN, $command,
+                    '-f', 'json',
+                    '-t', $htmlformat,
+                    @html_args);
+    error("Unable to open $command") unless $to_html_pid;
+
+    $pagestate{$page}{pandoc_extra_formats} = {};
+    foreach my $ext (keys %extra_formats) {
+        if ($bool_meta{"generate_$ext"}) {
+            export_file($page, $ext, $json_content, $command, @args);
+        } else {
+            remove_exported_file($page, $ext);
+        }
+    }
+
     print JSON_IN $json_content;
     close JSON_IN;
 
@@ -279,51 +583,199 @@ sub htmlize ($@) {
 
     $content = Encode::decode_utf8(join('', @html));
 
-    # Parse the title block out of the JSON and set the meta values
-    my @perl_content = @{decode_json($json_content)};
-    my %header_section = %{$perl_content[0]};
-    my @doc_title = @{$header_section{'docTitle'}};
-    my @doc_authors = @{$header_section{'docAuthors'}};
-    my $num_authors = @doc_authors;
-    my @primary_author = ();
-    if ($num_authors gt 0) {
-        @primary_author = @{$doc_authors[0]};
-    }
-    my @doc_date = @{$header_section{'docDate'}};
-
-    sub compile_string {
-        # The uncompiled string is an array of hashes containing words and 
-        # string with the word "Space".
-        my (@uncompiled_string) = @_;
-        my $compiled_string = '';
-        foreach my $word_or_space(@uncompiled_string) {
-            if (ref($word_or_space) eq "HASH") {
-                if ($word_or_space->{"Str"}) {
-                    $compiled_string .= $word_or_space->{"Str"};
-                }
+    # Reinstate placeholders for inline plugin:
+    $content =~ s{::INLINE::PLACEHOLDER::(\d+)::}
+                 {<div class="inline" id="$1"></div>}g;
+
+    return $content;
+}
+
+
+sub pagetemplate (@) {
+    my %params = @_;
+    my $page = $params{page};
+    my $template = $params{template};
+    foreach my $k (keys %{$pagestate{$page}{meta}}) {
+        next unless $k =~ /^pandoc_/;
+        $template->param($k => $pagestate{$page}{meta}{$k});
+    }
+}
+
+sub pageactions {
+    my %args = @_;
+    my $page = $args{page};
+    my @links = ();
+    return unless $pagestate{$page}{pandoc_extra_formats};
+    my @exts = sort {
+        $extra_formats{$a}->{order} <=> $extra_formats{$b}->{order}
+    } keys %{ $pagestate{$page}{pandoc_extra_formats} };
+    foreach my $ext (@exts) {
+        my $url = $pagestate{$page}{pandoc_extra_formats}{$ext};
+        next unless $url;
+        my $label = $extra_formats{$ext}->{label} || $ext;
+        push @links, qq[
+          <a href="$url"
+             class="extra-format-link"
+             title="Download $label version of this page"
+             target="_blank">$label</a>
+        ];
+    }
+    return @links;
+}
+
+sub export_file {
+    my ($page, $ext, $json_content, $command, @args) = @_;
+    my ($export_path, $export_url) = _export_file_path_and_url($page, $ext);
+    my $subdir = $1 if $export_path =~ /(.*)\//;
+    my @extra_args = @{ $extra_formats{$ext}->{extra} };
+    my $eopt = $ext eq 'pdf' ? 'latex' : $ext;
+    # Note that template in meta OVERRIDES template in config,
+    # while extra_options in meta are ADDED to extra_options in config.
+    my $template = $pagestate{$page}{meta}{"pandoc_".$eopt."_template"}
+                   || $config{"pandoc_".$eopt."_template"} || '';
+    if ($template) {
+        push @extra_args, ($ext =~ /^(docx|odt)$/
+                           ? "--reference-$ext=$template"
+                           : "--template=$template");
+    }
+    my $conf_extra = $config{"pandoc_".$eopt."_extra_options"};
+    my $conf_extra_custom = $pagestate{$page}{meta}{"pandoc_".$eopt."_extra_options"};
+    foreach my $cnf ($conf_extra, $conf_extra_custom) {
+        if (ref $cnf eq 'ARRAY' && @$cnf) {
+            push @extra_args, @$cnf;
+        }
+    }
+    my $pdf_cleanup = 0;
+    if (defined $pagestate{$page}{meta}{"pandoc_pdf_export_cleanup"}) {
+        $pdf_cleanup = $pagestate{$page}{meta}{"pandoc_pdf_export_cleanup"};
+    } elsif ($config{"pandoc_pdf_export_cleanup"}) {
+        $pdf_cleanup = 1;
+    }
+    # If the user has asked for native LaTeX bibliography handling in the
+    # extra_args for this export format (using --biblatex or --natbib),
+    # some extra care is needed. Among other things, we need an external
+    # tool for PDF generation. In this case, $indirect_pdf will be true.
+    my %maybe_non_citeproc = qw/latex 1 pdf 1 beamer 1/;
+    my $indirect_pdf = 0;
+    if ($maybe_non_citeproc{$ext} && grep { /^(?:--biblatex|--natbib)$/ } @extra_args) {
+        $indirect_pdf = 1 unless $ext eq 'latex'; # both for pdf and beamer
+        @args = grep { ! /--filter=.*pandoc-citeproc/ } @args;
+    }
+    eval {
+        if ($subdir && !-d $subdir) {
+            make_path($subdir) or die "Could not make_path $subdir: $!";
+        }
+        my $to_format = $extra_formats{$ext}->{format} || $ext;
+        my $tmp_export_path = $export_path;
+        $tmp_export_path =~ s/\.pdf$/.tex/ if $indirect_pdf;
+        open(EXPORT, "|-",
+             $command,
+             '-f' => 'json',
+             '-t' => $to_format,
+             '-o' => $tmp_export_path,
+             @args, @extra_args) or die "Could not open pipe for $ext: $!";
+        print EXPORT $json_content;
+        close EXPORT or die "Could not close pipe for $ext: $!";
+        if ($indirect_pdf && $tmp_export_path ne $export_path) {
+            my @latexmk_args = qw(-quiet -silent);
+            if (grep { /xelatex/ } @extra_args) {
+                push @latexmk_args, '-xelatex';
+            } elsif (grep { /lualatex/ } @extra_args) {
+                push @latexmk_args, '-lualatex';
+            } else {
+                push @latexmk_args, '-pdf';
             }
-            else {
-                $compiled_string .= ' ';
+            chdir $subdir or die "Could not chdir to $subdir: $!";
+            my $plain_fn = $1 if $tmp_export_path =~ /([^\/]+)$/;
+            $plain_fn =~ s/\.tex//;
+            system('latexmk', @latexmk_args, $plain_fn) == 0
+                or die "Could not run latexmk for pdf generation ($export_path): $!";
+            if ($pdf_cleanup) {
+                system('latexmk', '-c', '-quiet', '-silent', $plain_fn) == 0
+                    or die "Could not run latexmk for cleanup ($export_path): $!";
+                # These files are apparently not cleaned up by latexmk -c.
+                foreach ('run.xml', 'bbl') {
+                    my $fn = "$subdir/$plain_fn.$_";
+                    unlink($fn) if -f $fn;
+                }
             }
         }
-        return $compiled_string;
+        $pagestate{$page}{pandoc_extra_formats}{$ext} = $export_url;
+    };
+    if ($@) {
+        warn "EXPORT ERROR FOR $page (format: $ext): $@\n";
     }
+}
 
-    my $title = compile_string @doc_title;
-    my $author = compile_string @primary_author;
-    my $date = compile_string @doc_date;
-
-    if ($title) {
-        $pagestate{$page}{meta}{title} = $title;
+sub remove_exported_file {
+    my ($page, $ext) = @_;
+    my ($export_path, $export_url) = _export_file_path_and_url($page, $ext);
+    if (-f $export_path) {
+        eval { unlink $export_path or die "Could not unlink $export_path: $!" };
+        if ($@) {
+            warn "WARNING: remove_exported_file; page=$page, ext=$ext: $@\n";
+        }
     }
-    if ($author) {
-        $pagestate{$page}{meta}{author} = $author;
+}
+
+sub _export_file_path_and_url {
+    my ($page, $ext) = @_;
+    # the html file will end up in "$destdir/$page/index.html",
+    # while e.g. a pdf will be in "$destdir/$page/$page_minus_dirs.pdf".
+    my $extension = $extra_formats{$ext}->{ext} || $ext;
+    my $destdir = $config{destdir} || '.';
+    my $page_minus_dirs = $1 if $page =~ /([^\/]*)$/;
+    $page_minus_dirs ||= 'index';
+    my $export_path = "$destdir/$page/$page_minus_dirs.$extension";
+    my $export_url = $config{url};
+    $export_url .= "/" unless $export_url =~ /\/$/;
+    $export_url .= "$page/$page_minus_dirs.$extension";
+    return ($export_path, $export_url);
+}
+
+
+## compile_string and unwrap_c are used to make the meta data structures
+## easier to work with for perl.
+
+sub compile_string {
+    # Partially represents an item from the data structure in meta as a string.
+    my @uncompiled = @_;
+    return $uncompiled[0] if @uncompiled==1 && !ref($uncompiled[0]);
+    @uncompiled = @{$uncompiled[0]} if @uncompiled==1 && ref $uncompiled[0] eq 'ARRAY';
+    my $compiled_string = '';
+    foreach my $word_or_space (@uncompiled) {
+        next unless ref $word_or_space eq 'HASH';
+        my $type = $word_or_space->{'t'} || '';
+        $compiled_string .= compile_string(@{ $word_or_space->{c} }) if $type eq 'MetaInlines';
+        next unless $type eq 'Str' || $type eq 'Space' || $type eq 'MetaString';
+        $compiled_string .= $type eq 'Space' ? ' ' : $word_or_space->{c};
     }
-    if ($date) {
-        $pagestate{$page}{meta}{date} = $date;
+    return $compiled_string;
+}
+sub unwrap_c {
+    # Unwrap pandoc's MetaLists, MetaInlines, etc.
+    # Finds the deepest-level scalar value for 'c' in the data structure.
+    # Lists with one element are replaced with the scalar, lists with more
+    # than one element are returned as an arrayref containing scalars.
+    my $container = shift;
+    if (ref $container eq 'ARRAY' && @$container > 1) {
+        if (ref $container->[0] eq 'HASH' && $container->[0]->{t} =~ /^(?:Str|Space)$/) {
+            # handles scalar author fields
+            return join('', map { compile_string($_) } @$container);
+        } else {
+            return [map {unwrap_c($_)} @$container];
+        }
+    } elsif (ref $container eq 'ARRAY' && @$container) {
+        return unwrap_c($container->[0]);
+    } elsif (ref $container eq 'ARRAY') {
+        return;
+    } elsif (ref $container eq 'HASH' && $container->{c}) {
+        return unwrap_c($container->{c});
+    } elsif (ref $container) {
+        return;
+    } else {
+        return $container;
     }
-
-    return $content;
 }
 
-1
+1;