Insert "-" for empty strings

build.gradle

@@ -8,7 +8,7 @@ plugins {
 }
 
 group 'com.docutools'
-version = '8.2.0'
+version = '9.0.0-alpha.1'
 
 java {
     toolchain {

src/main/java/com/docutools/jocument/impl/ReflectionResolver.java

@@ -391,7 +391,7 @@ private Optional<PlaceholderData> doReflectiveResolve(String placeholderName, Lo
       }
       var wrappedProperty = getBeanProperty(placeholderName);
       if (wrappedProperty.isEmpty()) {
-        return Optional.of(new ScalarPlaceholderData<>("-"));
+        return Optional.of(new ScalarPlaceholderData<>(""));
       }
       return toPlaceholderData(placeholderName, locale, wrappedProperty.get());
     } catch (NoSuchMethodException | IllegalArgumentException e) {

src/main/java/com/docutools/jocument/impl/ScalarPlaceholderData.java

@@ -28,7 +28,11 @@ public PlaceholderType getType() {
 
   @Override
   public String toString() {
-    return stringifier.apply(value);
+    String string = stringifier.apply(value);
+    if (string == null || string.isEmpty()) {
+      return "-";
+    }
+    return string;
   }
 
   @Override

src/main/java/com/docutools/jocument/impl/excel/implementations/ExcelGenerator.java

@@ -128,7 +128,7 @@ private ModificationInformation replacePlaceholder(Cell cell, int offset) {
     // to resolve cell content such as "{{name}} {{crew}}", we match against the full string and resolve per match
     var matcher = ParsingUtils.matchPlaceholders(cellValue);
     excelWriter.addCell(cell, matcher.replaceAll(matchResult -> resolver.resolve(matchResult.group(1))
-        .orElse(new ScalarPlaceholderData<>("-"))
+        .orElse(new ScalarPlaceholderData<>(""))
         .toString()));
     return ModificationInformation.empty();
   }