fix ocl to verify rule

hl7templates/hl7templates-generator-jar/src/main/java/net/ihe/gazelle/tempgen/action/OCLGenerator.java

@@ -20,6 +20,7 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Objects;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
@@ -412,11 +413,31 @@ public class OCLGenerator {
                 ImportElementHandler.handleAddingElement(typeName);
             }
         } else {
-            res = "(not " + res + ".oclIsUndefined()) and " + res + "=" + valueDPathModified;
+            res = "(not (" + verifyAndModifyStructure(res) + ".oclIsUndefined())) and " + res + "=" + valueDPathModified;
         }
         return res;
     }
 
+    //            res = "(not (" + verifyAndModifyStructure(res) + ".oclIsUndefined())) and " + res + "=" + valueDPathModified;
+    // fix for the case where the path give a nullPointerException: observation.code.code
+    public static String verifyAndModifyStructure(String input) {
+        String[] attributeParts = input.split("\\.");
+        if (attributeParts.length == 0) {
+            return input;
+        }
+        StringBuilder modifiedStructure = new StringBuilder();
+        String currentObject = "";
+        for (int i = 0; i < attributeParts.length-1; i++) {
+            currentObject += (i == 0 ? "" : ".") + attributeParts[i];
+            modifiedStructure.append(currentObject).append(".oclIsUndefined()");
+            if (i < attributeParts.length - 1) {
+                modifiedStructure.append(" or ");
+            }
+        }
+
+        return modifiedStructure + input ;
+    }
+
     public String generateRuleToParentFromPath(ChoiceDefinition choiceDefinition) {
         DParent dparent = RuleDefinitionUtil.getDParentOfRuleDefinition((RuleDefinition) choiceDefinition.getParentObject());
         return this.generateRuleFromPath(dparent, (RuleDefinition) choiceDefinition.getParentObject());