From 1e65dde0e8b5a42890c382574c997fa9afeae9a8 Mon Sep 17 00:00:00 2001
From: Hancong Zhang <h.zhang6@student.tue.nl>
Date: Thu, 13 Aug 2026 19:15:39 +0200
Subject: [PATCH] add formatting attribute

---
 .../csl/internal/rendering/SDate.java         | 16 +++++++-
 .../csl/internal/rendering/SDatePart.java     |  5 ++-
 .../java/de/undercouch/citeproc/CSLTest.java  | 38 +++++++++++++++++++
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDate.java b/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDate.java
index 0d053d21..a1528ada 100644
--- a/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDate.java
+++ b/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDate.java
@@ -3,6 +3,7 @@
 import de.undercouch.citeproc.csl.CSLDate;
 import de.undercouch.citeproc.csl.internal.RenderContext;
 import de.undercouch.citeproc.csl.internal.behavior.Affixes;
+import de.undercouch.citeproc.csl.internal.behavior.FormattingAttributes;
 import de.undercouch.citeproc.csl.internal.locale.LDate;
 import de.undercouch.citeproc.csl.internal.token.TextToken;
 import de.undercouch.citeproc.csl.internal.token.Token;
@@ -32,6 +33,7 @@ public class SDate implements SRenderingElement {
     private final String datePartsAttr;
     private final List<SDatePart> dateParts = new ArrayList<>();
     private final Affixes affixes;
+    private final int formattingAttributes;
 
     /**
      * Creates the date element from an XML node
@@ -72,11 +74,23 @@ public SDate(Node node) {
         }
 
         affixes = new Affixes(node);
+        formattingAttributes = FormattingAttributes.of(node);
     }
 
     @Override
     public void render(RenderContext ctx) {
-        affixes.wrap(this::renderInternal).accept(ctx);
+        affixes.wrap(this::renderWithFormatting).accept(ctx);
+    }
+
+    private void renderWithFormatting(RenderContext ctx) {
+        if (formattingAttributes == 0) {
+            renderInternal(ctx);
+            return;
+        }
+
+        RenderContext tmp = new RenderContext(ctx);
+        renderInternal(tmp);
+        ctx.emit(tmp.getResult(), formattingAttributes);
     }
 
     private void renderInternal(RenderContext ctx) {
diff --git a/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDatePart.java b/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDatePart.java
index 5b1687b8..b9e7469d 100644
--- a/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDatePart.java
+++ b/citeproc-java/src/main/java/de/undercouch/citeproc/csl/internal/rendering/SDatePart.java
@@ -3,6 +3,7 @@
 import de.undercouch.citeproc.csl.internal.RenderContext;
 import de.undercouch.citeproc.csl.internal.SElement;
 import de.undercouch.citeproc.csl.internal.behavior.Affixes;
+import de.undercouch.citeproc.csl.internal.behavior.FormattingAttributes;
 import de.undercouch.citeproc.csl.internal.behavior.StripPeriods;
 import de.undercouch.citeproc.csl.internal.locale.LTerm;
 import de.undercouch.citeproc.helper.NodeHelper;
@@ -23,6 +24,7 @@ public class SDatePart implements SElement {
     private final Affixes affixes;
     private final StripPeriods stripPeriods;
     private final String rangeDelimiter;
+    private final int formattingAttributes;
 
     /**
      * Creates the date-part element from an XML node
@@ -40,6 +42,7 @@ public SDatePart(Node node) {
         form = NodeHelper.getAttrValue(node, "form");
         affixes = new Affixes(node);
         stripPeriods = new StripPeriods(node);
+        formattingAttributes = FormattingAttributes.of(node);
 
         String rd = NodeHelper.getAttrValue(node, "range-delimiter");
         rangeDelimiter = Objects.requireNonNullElse(rd, "–");
@@ -73,7 +76,7 @@ private void renderInternal(RenderContext ctx) {
         }
 
         if (value != null) {
-            ctx.emit(value);
+            ctx.emit(value, formattingAttributes);
         }
     }
 
diff --git a/citeproc-java/src/test/java/de/undercouch/citeproc/CSLTest.java b/citeproc-java/src/test/java/de/undercouch/citeproc/CSLTest.java
index f3fac18e..2728b71e 100644
--- a/citeproc-java/src/test/java/de/undercouch/citeproc/CSLTest.java
+++ b/citeproc-java/src/test/java/de/undercouch/citeproc/CSLTest.java
@@ -703,6 +703,44 @@ public void emptyAsciiDoc() throws Exception {
         );
     }
 
+    /**
+     * Make sure formatting attributes on date and date-part elements are
+     * preserved in rendered output.
+     * @throws Exception if something goes wrong
+     */
+    @Test
+    public void dateFormattingAttributes() throws Exception {
+        CSLItemData item = new CSLItemDataBuilder()
+                .id("DATE-FORMATTING")
+                .type(CSLType.ARTICLE_JOURNAL)
+                .issued(2007)
+                .build();
+
+        String dateStyle = "<style xmlns=\"http://purl.org/net/xbiblio/csl\" version=\"1.0\">"
+                + "<citation><layout><text value=\"1\"/></layout></citation>"
+                + "<bibliography><layout>"
+                + "<date variable=\"issued\" font-weight=\"bold\">"
+                + "<date-part name=\"year\"/>"
+                + "</date>"
+                + "</layout></bibliography>"
+                + "</style>";
+
+        String datePartStyle = "<style xmlns=\"http://purl.org/net/xbiblio/csl\" version=\"1.0\">"
+                + "<citation><layout><text value=\"1\"/></layout></citation>"
+                + "<bibliography><layout>"
+                + "<date variable=\"issued\">"
+                + "<date-part name=\"year\" font-weight=\"bold\"/>"
+                + "</date>"
+                + "</layout></bibliography>"
+                + "</style>";
+
+        String dateBibliography = CSL.makeAdhocBibliography(dateStyle, "html", item).makeString();
+        assertTrue(dateBibliography.contains("<span style=\"font-weight: bold\">2007</span>"));
+
+        String datePartBibliography = CSL.makeAdhocBibliography(datePartStyle, "html", item).makeString();
+        assertTrue(datePartBibliography.contains("<span style=\"font-weight: bold\">2007</span>"));
+    }
+
     /**
      * Test if parsing a style with multiple if nodes within a choose node
      * throws an exception