Duplicate first row DataTable Lazy virtualScroll

[bug007]

Hi,
With PrimeFaces 6.1, When I implement a LazyDataModel on a Datatable with virtualScroll, the fisrt page row is duplicate.

See this exemple with bean Item, LazyDataModel implementation and BrowserItems view :

Code: Select all

public class Item {
    private Integer itemIndex;
    private String itemValue;

    public Item(Integer itemIndex, String itemValue) {
        this.itemIndex = itemIndex;
        this.itemValue = itemValue;
    }

    public Integer getItemIndex() {
        return itemIndex;
    }

    public void setItemIndex(Integer itemIndex) {
        this.itemIndex = itemIndex;
    }

    public String getItemValue() {
        return itemValue;
    }

    public void setItemValue(String itemValue) {
        this.itemValue = itemValue;
    }       
}

LazyDataModel of Item

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public class LazyItemDataModel extends LazyDataModel<Item> {

    private List<Item> itemList;
    private List<Item> itemLazyList;

    public LazyItemDataModel() {
        this.itemList = new ArrayList<Item>();
        for (Integer i=0; i<=450; i++) {
            this.itemList.add(new Item(i, "ITEM - "+ i));
        }
    }

    @Override
    public Item getRowData(String rowKey) {
        return this.itemList.get(Integer.parseInt(rowKey));
    }

    @Override
    public Object getRowKey(Item item) {
        return item.getItemIndex();
    }

    @Override
    public List<Item> load(int first, int pageSize, List<SortMeta> multiSortMeta, Map<String, Object> filters) {
        this.itemLazyList = this.itemList.subList(first, first+pageSize);
        this.setRowCount(this.itemList.size());
        return this.itemLazyList;
    }
    
    public List<Item> getItemLazyList() {
        return itemLazyList;
    }

    public void setItemLazyList(List<Item> itemLazyList) {
        this.itemLazyList = itemLazyList;
    }
}

Bean Facade

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@ManagedBean
@ViewScoped
public class BrowserItem implements Serializable {

    private LazyDataModel<Item> listLazyDataModel;
    
    public BrowserItem() {
    }

    @PostConstruct
    public void init() {
        listLazyDataModel = new LazyItemDataModel();
    }

    public LazyDataModel<Item> getListLazyDataModel() {
        return listLazyDataModel;
    }

    public void setListLazyDataModel(LazyDataModel<Item> listLazyDataModel) {
        this.listLazyDataModel = listLazyDataModel;
    }
}

And view

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<h:form id="browseItem" prependId="false" >
                      <p:dataTable id="result" widgetVar="result"
                                     var="item" value="#{browserItem.listLazyDataModel}" 
                                     rowKey="#{item.itemIndex}"
                                     scrollable="true" scrollHeight="500" scrollWidth="100%" reflow="true" 
                                     sortMode="multiple" virtualScroll="true" scrollRows="50" lazy="true" liveScroll="true"
                                     >
                            <p:column sortBy="#{item.itemValue}" filterBy="#{item.itemIndex}" priority="2">
                                <h:outputText value="#{item.itemIndex}"/>
                            </p:column>
                            <p:column sortBy="#{item.itemValue}" filterBy="#{item.itemIndex}" priority="2">
                                <h:outputText value="#{item.itemValue}"/>
                            </p:column>
                        </p:dataTable>

            </h:form>

When you scroll the date the fisrt time, you can see after 50 rows, the same 50 rows !
After the first refresh, every thing look like ok (unless blanck page when each refresh)

Is it an issue OR is it a wrong property use for this type of Lazy Datatbel Scrolling?

Thanks a lot for your help.

[bug007]

Cf https://github.com/primefaces/primefaces/issues/3002