From 7de6d597d119a2fd0455fa8b838cfda12e646e27 Mon Sep 17 00:00:00 2001
From: Oliver Neill <7759984+odneill@users.noreply.github.com>
Date: Tue, 16 Jul 2024 11:13:14 +0100
Subject: [PATCH] Add minimal support for biblatex data annotations (#11506)

* Add minimal support for biblatex data annotations

Fixes #11505

* update changelog
---
 CHANGELOG.md                                    |  1 +
 .../org/jabref/logic/layout/LayoutHelper.java   | 17 +++++++++++++++--
 .../org/jabref/logic/layout/LayoutTest.java     | 13 +++++++++++++
 3 files changed, 29 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index f6a2d0baf60..972ca5c0142 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ Note that this project **does not** adhere to [Semantic Versioning](https://semv
 ### Added
 
 - We added support for selecting and using CSL Styles in JabRef's OpenOffice/LibreOffice integration for inserting bibliographic and in-text citations into a document. [#2146](https://github.com/JabRef/jabref/issues/2146), [#8893](https://github.com/JabRef/jabref/issues/8893)
+- Added minimal support for [biblatex data annotation](https://mirrors.ctan.org/macros/latex/contrib/biblatex/doc/biblatex.pdf#subsection.3.7) fields in .layout files. [#11505](https://github.com/JabRef/jabref/issues/11505)
 
 ### Changed
 
diff --git a/src/main/java/org/jabref/logic/layout/LayoutHelper.java b/src/main/java/org/jabref/logic/layout/LayoutHelper.java
index 0a01c49dac5..1a923f17b64 100644
--- a/src/main/java/org/jabref/logic/layout/LayoutHelper.java
+++ b/src/main/java/org/jabref/logic/layout/LayoutHelper.java
@@ -48,7 +48,7 @@ public LayoutHelper(Reader in,
                         List<Path> fileDirForDatabase,
                         LayoutFormatterPreferences preferences,
                         JournalAbbreviationRepository abbreviationRepository) {
-        this.in = new PushbackReader(Objects.requireNonNull(in));
+        this.in = new PushbackReader(Objects.requireNonNull(in), 2);
         this.preferences = Objects.requireNonNull(preferences);
         this.abbreviationRepository = abbreviationRepository;
         this.fileDirForDatabase = fileDirForDatabase;
@@ -262,7 +262,7 @@ private void parseField() throws IOException {
                 endOfFile = true;
             }
 
-            if (!Character.isLetter((char) c) && (c != '_')) {
+            if (!validChar(c) && !validAnnotation(c)) {
                 unread(c);
 
                 name = buffer == null ? "" : buffer.toString();
@@ -345,6 +345,19 @@ private void parseField() throws IOException {
         }
     }
 
+    private boolean validAnnotation(int c) throws IOException {
+        // Only accept annotations that are followed by a valid character
+        boolean annotation = ((c == '+') || (c == ':')) && validChar(peek());
+
+        return annotation;
+    }
+
+    private boolean validChar(int c) throws IOException {
+        boolean character = Character.isLetter((char) c) || (c == '_');
+
+        return character;
+    }
+
     private int peek() throws IOException {
         int c = read();
         unread(c);
diff --git a/src/test/java/org/jabref/logic/layout/LayoutTest.java b/src/test/java/org/jabref/logic/layout/LayoutTest.java
index 0e9134e4f52..e27e75380b2 100644
--- a/src/test/java/org/jabref/logic/layout/LayoutTest.java
+++ b/src/test/java/org/jabref/logic/layout/LayoutTest.java
@@ -12,6 +12,7 @@
 import org.jabref.model.entry.BibEntry;
 import org.jabref.model.entry.LinkedFile;
 import org.jabref.model.entry.field.StandardField;
+import org.jabref.model.entry.field.UnknownField;
 import org.jabref.model.entry.types.StandardEntryType;
 import org.jabref.model.entry.types.UnknownEntryType;
 
@@ -173,4 +174,16 @@ void customNameFormatter() throws IOException {
 
         assertEquals("JoeDoe and MaryJ", layoutText);
     }
+
+    @Test
+    void annotatedField() throws IOException {
+        UnknownField annotatedField = new UnknownField("author+an");
+        BibEntry entry = new BibEntry(StandardEntryType.Article)
+            .withField(annotatedField, "1:corresponding,2:highlight")
+            .withField(StandardField.AUTHOR, "Joe Doe and Mary Jane");
+
+        String layoutText = layout("\\author: \\author \\author+an", entry);
+
+        assertEquals("Joe Doe and Mary Jane: Joe Doe and Mary Jane 1:corresponding,2:highlight", layoutText);
+    }
 }