diff --git a/org.talend.librariesmanager/resources/java/routines/system/Document.java b/org.talend.librariesmanager/resources/java/routines/system/Document.java
index dd6bfc9a3c..f5caf14376 100644
--- a/org.talend.librariesmanager/resources/java/routines/system/Document.java
+++ b/org.talend.librariesmanager/resources/java/routines/system/Document.java
@@ -52,7 +52,7 @@ public class Document implements java.io.Serializable{
      * @param matchingMode
      * @return
      */
-    public List<Map<String, Object>> LookupDocument(String loopXPath, Map<String, Object> lookupInfo,
+    public List<Map<String, Object>> LookupDocument(String loopXPath,boolean isOptionalLoop, Map<String, Object> lookupInfo,
             Map<String, String> xpathOfResults, Map<String, String> nsMapping,
             Map<String, String> xpathToTypeMap,Map<String, String> xpathToPatternMap,String matchingMode) {
         if (doc == null || lookupInfo == null) {
@@ -66,7 +66,7 @@ public class Document implements java.io.Serializable{
         docToFlat.setDoc(document);
         docToFlat.setOriginalLoop(loopXPath);
         docToFlat.setXmlNameSpaceMap(nsMapping);
-        docToFlat.flatForLookup();
+        docToFlat.flatForLookup(isOptionalLoop);
         if(docToFlat.isLoopChanged()) {//never change the original lookup information object state
         	lookupInfo = docToFlat.getLookupInfo();
         	xpathOfResults = docToFlat.getXpathOfResults();
diff --git a/org.talend.librariesmanager/resources/java/routines/system/DocumentToFlat.java b/org.talend.librariesmanager/resources/java/routines/system/DocumentToFlat.java
index 04c1fd5d72..1920534ffc 100644
--- a/org.talend.librariesmanager/resources/java/routines/system/DocumentToFlat.java
+++ b/org.talend.librariesmanager/resources/java/routines/system/DocumentToFlat.java
@@ -52,8 +52,7 @@ public class DocumentToFlat {
 		if(this.isOptional && nodes.size() == 0 && !top) {
 			setParentAsLoop();
 			flat();
-		} 
-		if (nodes !=null ) {
+		} else if (nodes !=null ) {
 			//reset relative paths
 			if(currentLoop != originalLoop) {//not point to the same string
 				for(int i=0;i<currentRelativePathMappings.length;i++) {
@@ -182,20 +181,17 @@ public class DocumentToFlat {
 		this.xpathToPatternMap = xpathToPatternMap;
 	}
 	
-	public void flatForLookup() {
+	public void flatForLookup(boolean isOptionalLoop) {
 		XPath loopXpath = doc.createXPath(currentLoop);
 		loopXpath.setNamespaceURIs(xmlNameSpaceMap);
 		nodes = loopXpath.selectNodes(doc);
-		if(isOptional && nodes.size() == 0 && !top) {
+		if(isOptionalLoop && nodes.size() == 0 && !top) {
 			setParentAsLoop();
-			flatForLookup();
-		} 
-		
-		if(currentLoop != originalLoop) {//not point to the same string
+			flatForLookup(isOptionalLoop);
+		} else if(currentLoop != originalLoop) {//not point to the same string
 			loopChanged = true;
 			reset();
 		}
-		
 	}
 	
 	private void reset() {