How to retain selection list and check boxes after pagination while lazy loading in prime faces data table?

Question

I implemented lazy loading at prime faces data table. It is working fine but when page is changed the selection is cleared. How to retain the selection at some other pages when page is changed and return back to the page. I found one related question here.

This answer helped me to keep the selected objects but failed to keep check boxes at table when come back to the page.

using Prime Faces version 6.2

I think there has been some work in this area since PF 6.2 that already resolves this issue. This sounds familiar and I feel like it is fixed in a later version. — Melloware, Jul 09 '21 at 16:35
But I can't change the prime faces version so I need some work around at bean to resolve this. Thanks for help — Mohammedsameer Inamdar, Jul 09 '21 at 18:03
See this thread: https://github.com/primefaces/primefaces/issues/1833 it has some solutions posted in there. — Melloware, Jul 09 '21 at 19:03

score 1 · Answer 1 · answered Jul 09 '21 at 19:07

Since OP doesn't want to upgrade above 6.2 the solution is a workaround listed here: https://forum.primefaces.org/viewtopic.php?f=3&t=47224

Add an AJAX toggleSelect event

<p:ajax event="toggleSelect" 
global="false" 
immediate="true"  
update=":usersManagerForm:usersTable:usersActions" 
listener="#{usersManagerBean.onToggleSelect}" />

And backing bean method:

public void onToggleSelect(ToggleSelectEvent event) {
        List<Compte> comptesListOfCurrentPage = (List<Compte>) compteLazyDataModel.getWrappedData();
        if(event.isSelected()) {
            selectedComptesList.addAll(comptesListOfCurrentPage);
        } else {
            selectedComptesList.removeAll(comptesListOfCurrentPage);
        }
    }

This event triggers only for toggle not for single row selection. thanks. — Mohammedsameer Inamdar, Jul 10 '21 at 03:15

score 1 · Accepted Answer · answered Jul 10 '21 at 05:48

I got the solution with the help of 2 answers

.xhtml

<p:dataTable selection="#{myBean.selectedRows}" ... >
   <p:ajax event="rowSelectCheckbox" process="@this" listener="#{myBean.onSelectRow}" />
   <p:ajax event="rowUnselectCheckbox" process="@this" listener="#{myBean.onUnselectRow}" />
<p:ajax event="page" process="@this" listener="#{myBean.onPagination}" />
<p:ajax event="toggleSelect" process="@this" listener="#{myBean.onToggle}" />
   <p:column selectionMode="multiple" ... />
    ...
 </p:dataTable>

.java

    private List<MyRowClass> selectedRows;
    private List<MyRowClass> selectedRowsSaved;

    ...

    public void onSelectRow(SelectEvent event){
        selectedRowsSaved.add((MyRowClass) event.getObject());
    }

    public void onUnselectRow(UnselectEvent event){
        selectedRowsSaved.remove((MyRowClass) event.getObject());
    }
    
    public void onToggle(ToggleSelectEvent event){
    List<Object> completeListOfCurrentPage = (List<Object>) compteLazyDataModel.getWrappedData();
        if(event.isSelected()) {
            selectedRowsSaved.addAll(comptesListOfCurrentPage);
        } else {
            selectedRowsSaved.removeAll(comptesListOfCurrentPage);
        }
    }

    public void onPagination(){
        if(selectedRowsSaved!=null && selectedRowsSaved.isEmpty()}{
            selectedRows.addAll(selectedRowsSaved);
        }
    }
    public List<MyRowClass> getSelectedRows(){
        return selectedRowsSaved;
    }

    public void setSelectedRows(List<MyRowClass> selectedRows){
        this.selectedRows = selectedRows;
    }

How to retain selection list and check boxes after pagination while lazy loading in prime faces data table?

2 Answers2