Follow up fixes for Date Groups (#14241)

* Follow up fixes for Date Groups

Fix exception for right clck menu
include year
simply date extracting

* var name

Author: Siedlerchr

jabgui/src/main/java/org/jabref/gui/groups/GroupNodeViewModel.java

@@ -40,6 +40,7 @@
 import org.jabref.model.groups.AutomaticGroup;
 import org.jabref.model.groups.AutomaticKeywordGroup;
 import org.jabref.model.groups.AutomaticPersonsGroup;
+import org.jabref.model.groups.DateGroup;
 import org.jabref.model.groups.ExplicitGroup;
 import org.jabref.model.groups.GroupEntryChanger;
 import org.jabref.model.groups.GroupTreeNode;
@@ -464,6 +465,8 @@ public boolean canAddEntriesIn() {
             return false;
         } else if (group instanceof AutomaticDateGroup) {
             return false;
+        } else if (group instanceof DateGroup) {
+            return false;
         } else {
             throw new UnsupportedOperationException("canAddEntriesIn method not yet implemented in group: " + group.getClass().getName());
         }
@@ -508,6 +511,7 @@ public boolean canAddGroupsIn() {
             case AutomaticKeywordGroup _,
                  AutomaticPersonsGroup _,
                  AutomaticDateGroup _,
+                 DateGroup _,
                  SmartGroup _ ->
                     false;
             case KeywordGroup _ ->
@@ -534,6 +538,7 @@ public boolean canRemove() {
                  AutomaticKeywordGroup _,
                  AutomaticPersonsGroup _,
                  AutomaticDateGroup _,
+                 DateGroup _,
                  TexGroup _ ->
                     true;
             case KeywordGroup _ ->
@@ -553,6 +558,7 @@ public boolean isEditable() {
         AbstractGroup group = groupNode.getGroup();
         return switch (group) {
             case AllEntriesGroup _,
+                 DateGroup _,
                  SmartGroup _ ->
                     false;
             case ExplicitGroup _,

jablib/src/main/java/org/jabref/model/entry/field/FieldFactory.java

@@ -193,8 +193,12 @@ public static Set<Field> getPersonNameFields() {
         return getFieldsFiltered(field -> field.getProperties().contains(FieldProperty.PERSON_NAMES));
     }
 
+    /// Gets all fields with [FieldProperty#DATE].
+    /// Also includes [StandardField#YEAR].
+    ///
+    /// @return Set of fields
     public static Set<Field> getDateFields() {
-        return getFieldsFiltered(field -> field.getProperties().contains(FieldProperty.DATE));
+        return getFieldsFiltered(field -> field.getProperties().contains(FieldProperty.DATE) || field == StandardField.YEAR);
     }
 
     private static Set<Field> getFieldsFiltered(Predicate<Field> selector) {

jablib/src/main/java/org/jabref/model/groups/AutomaticDateGroup.java

@@ -49,20 +49,20 @@ public DateGranularity getGranularity() {
     public Set<GroupTreeNode> createSubgroups(BibEntry entry) {
         var out = new LinkedHashSet<GroupTreeNode>();
 
-        DateGroup.extractDate(field, entry).ifPresent(d -> {
+        DateGroup.extractDate(field, entry).ifPresent(date -> {
             switch (granularity) {
                 case YEAR -> {
-                    DateGroup.extractYear(field, entry).ifPresent(y -> {
-                        String key = "%04d".formatted(y);
+                    date.getYear().ifPresent(year -> {
+                        String key = "%04d".formatted(year);
                         out.add(new GroupTreeNode(new DateGroup(key, GroupHierarchyType.INDEPENDENT, field, key)));
                     });
                 }
                 case MONTH ->
-                        DateGroup.getDateKey(d, "YYYY-MM").ifPresent(key -> {
+                        DateGroup.getDateKey(date, "YYYY-MM").ifPresent(key -> {
                             out.add(new GroupTreeNode(new DateGroup(key, GroupHierarchyType.INDEPENDENT, field, key)));
                         });
                 case FULL_DATE ->
-                        DateGroup.getDateKey(d, "YYYY-MM-DD").ifPresent(key -> {
+                        DateGroup.getDateKey(date, "YYYY-MM-DD").ifPresent(key -> {
                             out.add(new GroupTreeNode(new DateGroup(key, GroupHierarchyType.INDEPENDENT, field, key)));
                         });
             }

jablib/src/main/java/org/jabref/model/groups/DateGroup.java

@@ -22,12 +22,6 @@ public DateGroup(String groupName, GroupHierarchyType context, Field searchField
         this.date = date;
     }
 
-    static Optional<Integer> extractYear(Field field, BibEntry bibEntry) {
-        return bibEntry.getField(field)
-                       .flatMap(Date::parse)
-                       .flatMap(Date::getYear);
-    }
-
     static Optional<Date> extractDate(Field field, BibEntry entry) {
         boolean isCore =
                 (field == StandardField.DATE)
@@ -58,7 +52,7 @@ static Optional<String> getDateKey(Date d, String dateKeyFormat) {
         Optional<Integer> y = d.getYear();
         return switch (numOfdashes) {
             case 0 ->
-                    y.map(val -> "%04d".formatted(val)); // "YYYY"
+                    y.map("%04d"::formatted); // "YYYY"
             case 1 -> { // "YYYY-MM"
                 if (d.getYear().isPresent() && d.getMonth().isPresent()) {
                     String out = "%04d-%02d".formatted(d.getYear().get(), d.getMonth().get().getNumber());