Merge pull request #1860 from scireum/feature/aha/SIRI-857

Permits sorting lookup values by a given field.

src/main/java/sirius/biz/codelists/LookupTable.java

@@ -23,6 +23,7 @@
 import javax.annotation.Nullable;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
@@ -60,7 +61,7 @@ public abstract class LookupTable {
     public static final String CONFIG_KEY_MAPPING_FIELD = "mappingsField";
     private final String mappingsField;
 
-    enum CodeCase {
+    protected enum CodeCase {
         LOWER, UPPER, VERBATIM
     }
 
@@ -428,6 +429,19 @@ public String forceNormalize(String code) {
         return normalize(code).orElseGet(() -> normalizeCodeValue(code));
     }
 
+    /**
+     * Provides a comparator which sorts codes by the occurrence order within the list.
+     *
+     * @param field the field to sort by. This can be any numeric field. Note that the YAML loader for Jupiter can
+     *              generate such fields when specifying a <tt>rowNumber</tt>.
+     *              See: <a href="https://docs.rs/jupiter/latest/jupiter/idb/idb_yaml_loader/index.html">YAML Loader</a>
+     * @return a comparator to sort codes by their occurrence order
+     */
+    public Comparator<String> comparator(String field) {
+        return Comparator.<String, Integer>comparing(code -> fetchFieldValue(code, field).asInt(100))
+                         .thenComparing(this::normalizeCodeValue);
+    }
+
     /**
      * Normalizes the given code by using the given mapping.
      * <p>