nixpkgs/nixos/doc/manual/default.nix
aszlig f865d0feab
nixos: Split paras by \n\n in option descriptions
What annoyed me for a long time was the fact, that in order to break
into a new paragraph, you need to insert </para><para> in the
description attribute of an option.

Now we will automatically create <para/> elements for every block that
is separated by two consecutive newlines.

I first tried to do this within options-to-docbook.xsl, but it turns
out[1] that this isn't directly possible with XSLT 1.0, so I added
another XSLT file that postprocesses the option descriptions that are
now enclosed in <nixos:option-description/> by options-to-docbook.xsl.

The splitting itself is a bit more involved, because we can't simply
split on every \n\n because we'd also split text nodes of elements, for
example:

  <screen><![CDATA[

    one line

    another one

  ]]></screen>

This would create one <para/> element for "one line" and another for
"another line", which we obviously don't want because <screen/> is used
to display verbatim contents of what a user is seeing on the screen.

So what we do instead is splitting *only* the top-level text nodes
within the outermost <para/> and leave all elements as-is. If there are
more than one <para/> elements at the top-level, we simply don't process
it at all, because the description then already contains </para><para>.

https://www.mhonarc.org/archive/html/xsl-list/2012-09/msg00319.html

Signed-off-by: aszlig <aszlig@nix.build>
Cc: @edolstra, @domenkozar
2018-09-02 08:10:37 +02:00

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{ pkgs, options, config, version, revision, extraSources ? [] }:
with pkgs;
let
lib = pkgs.lib;
# Remove invisible and internal options.
optionsListVisible = lib.filter (opt: opt.visible && !opt.internal) (lib.optionAttrSetToDocList options);
# Replace functions by the string <function>
substFunction = x:
if builtins.isAttrs x then lib.mapAttrs (name: substFunction) x
else if builtins.isList x then map substFunction x
else if lib.isFunction x then "<function>"
else x;
# Generate DocBook documentation for a list of packages. This is
# what `relatedPackages` option of `mkOption` from
# ../../../lib/options.nix influences.
#
# Each element of `relatedPackages` can be either
# - a string: that will be interpreted as an attribute name from `pkgs`,
# - a list: that will be interpreted as an attribute path from `pkgs`,
# - an attrset: that can specify `name`, `path`, `package`, `comment`
# (either of `name`, `path` is required, the rest are optional).
genRelatedPackages = packages:
let
unpack = p: if lib.isString p then { name = p; }
else if lib.isList p then { path = p; }
else p;
describe = args:
let
title = args.title or null;
name = args.name or (lib.concatStringsSep "." args.path);
path = args.path or [ args.name ];
package = args.package or (lib.attrByPath path (throw "Invalid package attribute path `${toString path}'") pkgs);
in "<listitem>"
+ "<para><literal>${lib.optionalString (title != null) "${title} aka "}pkgs.${name} (${package.meta.name})</literal>"
+ lib.optionalString (!package.meta.available) " <emphasis>[UNAVAILABLE]</emphasis>"
+ ": ${package.meta.description or "???"}.</para>"
+ lib.optionalString (args ? comment) "\n<para>${args.comment}</para>"
# Lots of `longDescription's break DocBook, so we just wrap them into <programlisting>
+ lib.optionalString (package.meta ? longDescription) "\n<programlisting>${package.meta.longDescription}</programlisting>"
+ "</listitem>";
in "<itemizedlist>${lib.concatStringsSep "\n" (map (p: describe (unpack p)) packages)}</itemizedlist>";
optionsListDesc = lib.flip map optionsListVisible (opt: opt // {
# Clean up declaration sites to not refer to the NixOS source tree.
declarations = map stripAnyPrefixes opt.declarations;
}
// lib.optionalAttrs (opt ? example) { example = substFunction opt.example; }
// lib.optionalAttrs (opt ? default) { default = substFunction opt.default; }
// lib.optionalAttrs (opt ? type) { type = substFunction opt.type; }
// lib.optionalAttrs (opt ? relatedPackages && opt.relatedPackages != []) { relatedPackages = genRelatedPackages opt.relatedPackages; });
# We need to strip references to /nix/store/* from options,
# including any `extraSources` if some modules came from elsewhere,
# or else the build will fail.
#
# E.g. if some `options` came from modules in ${pkgs.customModules}/nix,
# you'd need to include `extraSources = [ pkgs.customModules ]`
prefixesToStrip = map (p: "${toString p}/") ([ ../../.. ] ++ extraSources);
stripAnyPrefixes = lib.flip (lib.fold lib.removePrefix) prefixesToStrip;
# Custom "less" that pushes up all the things ending in ".enable*"
# and ".package*"
optionLess = a: b:
let
ise = lib.hasPrefix "enable";
isp = lib.hasPrefix "package";
cmp = lib.splitByAndCompare ise lib.compare
(lib.splitByAndCompare isp lib.compare lib.compare);
in lib.compareLists cmp a.loc b.loc < 0;
# Customly sort option list for the man page.
optionsList = lib.sort optionLess optionsListDesc;
# Convert the list of options into an XML file.
optionsXML = builtins.toFile "options.xml" (builtins.toXML optionsList);
optionsDocBook = runCommand "options-db.xml" {} ''
optionsXML=${optionsXML}
if grep /nixpkgs/nixos/modules $optionsXML; then
echo "The manual appears to depend on the location of Nixpkgs, which is bad"
echo "since this prevents sharing via the NixOS channel. This is typically"
echo "caused by an option default that refers to a relative path (see above"
echo "for hints about the offending path)."
exit 1
fi
${buildPackages.libxslt.bin}/bin/xsltproc \
--stringparam revision '${revision}' \
-o intermediate.xml ${./options-to-docbook.xsl} $optionsXML
${buildPackages.libxslt.bin}/bin/xsltproc \
-o "$out" ${./postprocess-option-descriptions.xsl} intermediate.xml
'';
sources = lib.sourceFilesBySuffices ./. [".xml"];
modulesDoc = builtins.toFile "modules.xml" ''
<section xmlns:xi="http://www.w3.org/2001/XInclude" id="modules">
${(lib.concatMapStrings (path: ''
<xi:include href="${path}" />
'') (lib.catAttrs "value" config.meta.doc))}
</section>
'';
generatedSources = runCommand "generated-docbook" {} ''
mkdir $out
ln -s ${modulesDoc} $out/modules.xml
ln -s ${optionsDocBook} $out/options-db.xml
printf "%s" "${version}" > $out/version
'';
copySources =
''
cp -prd $sources/* . # */
ln -s ${generatedSources} ./generated
chmod -R u+w .
'';
toc = builtins.toFile "toc.xml"
''
<toc role="chunk-toc">
<d:tocentry xmlns:d="http://docbook.org/ns/docbook" linkend="book-nixos-manual"><?dbhtml filename="index.html"?>
<d:tocentry linkend="ch-options"><?dbhtml filename="options.html"?></d:tocentry>
<d:tocentry linkend="ch-release-notes"><?dbhtml filename="release-notes.html"?></d:tocentry>
</d:tocentry>
</toc>
'';
manualXsltprocOptions = toString [
"--param section.autolabel 1"
"--param section.label.includes.component.label 1"
"--stringparam html.stylesheet 'style.css overrides.css highlightjs/mono-blue.css'"
"--stringparam html.script './highlightjs/highlight.pack.js ./highlightjs/loader.js'"
"--param xref.with.number.and.title 1"
"--param toc.section.depth 3"
"--stringparam admon.style ''"
"--stringparam callout.graphics.extension .svg"
"--stringparam current.docid manual"
"--param chunk.section.depth 0"
"--param chunk.first.sections 1"
"--param use.id.as.filename 1"
"--stringparam generate.toc 'book toc appendix toc'"
"--stringparam chunk.toc ${toc}"
];
manual-combined = runCommand "nixos-manual-combined"
{ inherit sources;
nativeBuildInputs = [ buildPackages.libxml2.bin buildPackages.libxslt.bin ];
meta.description = "The NixOS manual as plain docbook XML";
}
''
${copySources}
xmllint --xinclude --output ./manual-combined.xml ./manual.xml
xmllint --xinclude --noxincludenode \
--output ./man-pages-combined.xml ./man-pages.xml
# outputs the context of an xmllint error output
# LEN lines around the failing line are printed
function context {
# length of context
local LEN=6
# lines to print before error line
local BEFORE=4
# xmllint output lines are:
# file.xml:1234: there was an error on line 1234
while IFS=':' read -r file line rest; do
echo
if [[ -n "$rest" ]]; then
echo "$file:$line:$rest"
local FROM=$(($line>$BEFORE ? $line - $BEFORE : 1))
# number lines & filter context
nl --body-numbering=a "$file" | sed -n "$FROM,+$LEN p"
else
if [[ -n "$line" ]]; then
echo "$file:$line"
else
echo "$file"
fi
fi
done
}
function lintrng {
xmllint --debug --noout --nonet \
--relaxng ${docbook5}/xml/rng/docbook/docbook.rng \
"$1" \
2>&1 | context 1>&2
# ^ redirect assumes xmllint doesnt print to stdout
}
lintrng manual-combined.xml
lintrng man-pages-combined.xml
mkdir $out
cp manual-combined.xml $out/
cp man-pages-combined.xml $out/
'';
olinkDB = runCommand "manual-olinkdb"
{ inherit sources;
nativeBuildInputs = [ buildPackages.libxml2.bin buildPackages.libxslt.bin ];
}
''
xsltproc \
${manualXsltprocOptions} \
--stringparam collect.xref.targets only \
--stringparam targets.filename "$out/manual.db" \
--nonet \
${docbook_xsl_ns}/xml/xsl/docbook/xhtml/chunktoc.xsl \
${manual-combined}/manual-combined.xml
cat > "$out/olinkdb.xml" <<EOF
<?xml version="1.0" encoding="utf-8"?>
<!DOCTYPE targetset SYSTEM
"file://${docbook_xsl_ns}/xml/xsl/docbook/common/targetdatabase.dtd" [
<!ENTITY manualtargets SYSTEM "file://$out/manual.db">
]>
<targetset>
<targetsetinfo>
Allows for cross-referencing olinks between the manpages
and manual.
</targetsetinfo>
<document targetdoc="manual">&manualtargets;</document>
</targetset>
EOF
'';
in rec {
inherit generatedSources;
# The NixOS options in JSON format.
optionsJSON = runCommand "options-json"
{ meta.description = "List of NixOS options in JSON format";
}
''
# Export list of options in different format.
dst=$out/share/doc/nixos
mkdir -p $dst
cp ${builtins.toFile "options.json" (builtins.unsafeDiscardStringContext (builtins.toJSON
(builtins.listToAttrs (map (o: { name = o.name; value = removeAttrs o ["name" "visible" "internal"]; }) optionsList))))
} $dst/options.json
mkdir -p $out/nix-support
echo "file json $dst/options.json" >> $out/nix-support/hydra-build-products
''; # */
# Generate the NixOS manual.
manual = runCommand "nixos-manual"
{ inherit sources;
nativeBuildInputs = [ buildPackages.libxml2.bin buildPackages.libxslt.bin ];
meta.description = "The NixOS manual in HTML format";
allowedReferences = ["out"];
}
''
# Generate the HTML manual.
dst=$out/share/doc/nixos
mkdir -p $dst
xsltproc \
${manualXsltprocOptions} \
--stringparam target.database.document "${olinkDB}/olinkdb.xml" \
--nonet --output $dst/ \
${docbook_xsl_ns}/xml/xsl/docbook/xhtml/chunktoc.xsl \
${manual-combined}/manual-combined.xml
mkdir -p $dst/images/callouts
cp ${docbook_xsl_ns}/xml/xsl/docbook/images/callouts/*.svg $dst/images/callouts/
cp ${../../../doc/style.css} $dst/style.css
cp ${../../../doc/overrides.css} $dst/overrides.css
cp -r ${pkgs.documentation-highlighter} $dst/highlightjs
mkdir -p $out/nix-support
echo "nix-build out $out" >> $out/nix-support/hydra-build-products
echo "doc manual $dst" >> $out/nix-support/hydra-build-products
''; # */
manualEpub = runCommand "nixos-manual-epub"
{ inherit sources;
buildInputs = [ libxml2.bin libxslt.bin zip ];
}
''
# Generate the epub manual.
dst=$out/share/doc/nixos
xsltproc \
${manualXsltprocOptions} \
--stringparam target.database.document "${olinkDB}/olinkdb.xml" \
--nonet --xinclude --output $dst/epub/ \
${docbook_xsl_ns}/xml/xsl/docbook/epub/docbook.xsl \
${manual-combined}/manual-combined.xml
mkdir -p $dst/epub/OEBPS/images/callouts
cp -r ${docbook_xsl_ns}/xml/xsl/docbook/images/callouts/*.svg $dst/epub/OEBPS/images/callouts # */
echo "application/epub+zip" > mimetype
manual="$dst/nixos-manual.epub"
zip -0Xq "$manual" mimetype
cd $dst/epub && zip -Xr9D "$manual" *
rm -rf $dst/epub
mkdir -p $out/nix-support
echo "doc-epub manual $manual" >> $out/nix-support/hydra-build-products
'';
# Generate the NixOS manpages.
manpages = runCommand "nixos-manpages"
{ inherit sources;
nativeBuildInputs = [ buildPackages.libxml2.bin buildPackages.libxslt.bin ];
allowedReferences = ["out"];
}
''
# Generate manpages.
mkdir -p $out/share/man
xsltproc --nonet \
--param man.output.in.separate.dir 1 \
--param man.output.base.dir "'$out/share/man/'" \
--param man.endnotes.are.numbered 0 \
--param man.break.after.slash 1 \
--stringparam target.database.document "${olinkDB}/olinkdb.xml" \
${docbook_xsl_ns}/xml/xsl/docbook/manpages/docbook.xsl \
${manual-combined}/man-pages-combined.xml
'';
}