From 5aed67c94d15a847d807092b987392595108ada1 Mon Sep 17 00:00:00 2001
From: Vincenzo Mantova <xworld21@users.sf.net>
Date: Sun, 2 Apr 2023 12:26:45 +0100
Subject: [PATCH] Add f:resource() for adding resources from XSLT

---
 lib/LaTeXML/Common/XML/XSLT.pm                |  4 ++++
 lib/LaTeXML/Post/XSLT.pm                      |  8 +++++++
 lib/LaTeXML/resources/XSLT/LaTeXML-common.xsl | 22 +++++++++++++++++++
 3 files changed, 34 insertions(+)

diff --git a/lib/LaTeXML/Common/XML/XSLT.pm b/lib/LaTeXML/Common/XML/XSLT.pm
index a0f7cfda95..936eb1c29b 100644
--- a/lib/LaTeXML/Common/XML/XSLT.pm
+++ b/lib/LaTeXML/Common/XML/XSLT.pm
@@ -31,5 +31,9 @@ sub transform {
   my ($self, $document, %params) = @_;
   return $$self{stylesheet}->transform($document, %params); }
 
+sub register_function {
+  my ($self, $uri, $name, $subref) = @_;
+  return $$self{stylesheet}->register_function($uri, $name, $subref); }
+
 #======================================================================
 1;
diff --git a/lib/LaTeXML/Post/XSLT.pm b/lib/LaTeXML/Post/XSLT.pm
index 385269cd88..c8799e0d5d 100644
--- a/lib/LaTeXML/Post/XSLT.pm
+++ b/lib/LaTeXML/Post/XSLT.pm
@@ -59,6 +59,14 @@ sub process {
   return unless $$self{stylesheet};
   # # Set up the Stylesheet parameters; making pathname parameters relative to document
   my %params = %{ $$self{parameters} };
+  # set up XSLT extension function f:_copy-resource(src, type)
+  $$self{stylesheet}->register_function('http://dlmf.nist.gov/LaTeXML/functions', '_copy-resource', sub {
+      # values can be scalars or XML::LibXML::NodeList
+      my ($src, $type) = @_;
+      return Warn('malformed', '', $self, 'f:_copy-resource() requires at least one argument') unless defined $src;
+      # string interpolation converts node lists to the concatenation of all the string values
+      return $self->copyResource($doc, "$src", defined $type ? ("$type") : ());
+  });
   # Deal with any resources embedded within the document
   if (my @resnodes = $doc->findnodes('//ltx:resource[@src]')) {
     if ($$self{noresources}) {
diff --git a/lib/LaTeXML/resources/XSLT/LaTeXML-common.xsl b/lib/LaTeXML/resources/XSLT/LaTeXML-common.xsl
index c0219ae2c5..40c8ef0cc3 100644
--- a/lib/LaTeXML/resources/XSLT/LaTeXML-common.xsl
+++ b/lib/LaTeXML/resources/XSLT/LaTeXML-common.xsl
@@ -154,6 +154,28 @@
     <func:result><xsl:value-of select="$url"/></func:result>
   </func:function>
 
+  <!-- Return the destination url of a resource: f:resource(src, mimetype?)
+       When using latexmlpost, f:resource() is translated to a call to
+       LaTeXML::Post::XSLT::copyResource, which (if $src is not a URL) copies
+       $src to the destination directory and returns the location of the copy
+       relative to the destination directory. $mimetype, if present, is used to
+       search for $src in the LaTeXML distribution as well.
+       With other XSLT processors, f:resource returns $src unchanged.
+  -->
+  <func:function name="f:resource">
+    <xsl:param name="src"/>
+    <xsl:param name="mimetype"/>
+    <xsl:choose>
+      <!-- latexmlpost exports copyResource as 'f:_copy-resource' -->
+      <xsl:when test="function-available('f:_copy-resource')">
+        <func:result select="f:_copy-resource($src,$mimetype)"/>
+      </xsl:when>
+      <xsl:otherwise>
+        <func:result select="$src"/>
+      </xsl:otherwise>
+    </xsl:choose>
+  </func:function>
+
   <func:function name="f:class-pref">
     <xsl:param name="prefix"/>
     <xsl:param name="string"/>