diff --git a/src/main/webapp/resources/js/base/dataset.js b/src/main/webapp/resources/js/base/dataset.js
index 9ec9861a..26d8ea95 100644
--- a/src/main/webapp/resources/js/base/dataset.js
+++ b/src/main/webapp/resources/js/base/dataset.js
@@ -475,7 +475,7 @@ class Dataset {
 		this._byKeys = {};
 		this._current = null;
 		
-		let data = this._getDataItems(obj);
+		let data = this._getDataItems(obj = obj || {});
 		this._items = data.items;
 		this._byKeys = data.byKeys;
 		/*
@@ -498,7 +498,6 @@ class Dataset {
 	}
 	
 	_getDataItems(obj) {
-		obj = obj || {};
 		let array = Array.isArray(obj) ? obj : this.conf.dataGetter(obj) || [];
 		if (!Array.isArray(array))
 			throw new Error("The data must be an array");
@@ -533,7 +532,7 @@ class Dataset {
 			return this.setData(obj);
 		
 		let state = this.state;
-		let data = this._getDataItems(obj);
+		let data = this._getDataItems(obj = obj || {});
 		this._items = this._items.concat(data.items);
 		this._byKeys = {
 			...this._byKeys,