PrimeFaces Datatable: How to receive selected rows values? - jsf

Question

I use Prime Faces 6.2 to make a data table with checked column:
<p:dataTable id="#{prefix}List"
value="#{tickets}"
lazy="true"
paginator="true"
paginatorTemplate="{FirstPageLink} {PreviousPageLink} {CurrentPageReport} {NextPageLink} {LastPageLink}"
currentPageReportTemplate="{startRecord}-{endRecord} из {totalRecords}"
rows="20"
rowKey="#{ticket.id}"
var="ticket"
emptyMessage="Записи в данной категории отсутствуют">
<p:ajax event="toggleSelect" listener="#{ticketForm.onAllSelect}" process="#this" partialSubmit="true" />
<p:ajax event="rowSelectCheckbox" listener="#{ticketForm.onSelect}" update=":protocolForm" />
<p:ajax event="rowUnselectCheckbox" listener="#{ticketForm.onUnselect}" update=":protocolForm" />
<p:ajax event="rowSelect" listener="#{ticketForm.onSelect}" update=":protocolForm" />
<p:ajax event="rowUnselect" listener="#{ticketForm.onUnselect}" update=":protocolForm" />
<p:column selectionMode="multiple" style="width:40px; text-align:center" />
More specifically, when a header checkbox is selected I want to receive all selected rows data on server-side and use IDs of each row. Also, there's logic that helps to resolve a goal of hidding/rendering a page button when at least one checkbox is selected.
For this purpose I need manualy intercept a row/checkbox selection event and record IDs from it when a button pushed, so I can't use selection attribute of dataTable using such logic.
On server-side I have several event-listeners:
private Set<AbstractMTSBUExportTicket> abstractMTSBUExportTickets = new HashSet<>();
public Set<AbstractMTSBUExportTicket> getAbstractMTSBUExportTickets() {
return abstractMTSBUExportTickets;
}
public void onSelect(SelectEvent event) {
abstractMTSBUExportTickets.add((AbstractMTSBUExportTicket) event.getObject());
}
public void onUnselect(UnselectEvent event) {
abstractMTSBUExportTickets.remove(event.getObject());
}
public void onAllSelect(ToggleSelectEvent event) {
// do smth
}
Unfortunately, ToggleSelectEvent has only information about data-table itself within.
None information about rows I couldn't find. Also I tried to add process="#this" partialSubmit="true" attributes but seems like they do different actions.
So, could you give me an example of how it's possible to retrieve such data from an event object?
Should I use another way to solve it? Thanks for your answers in advance.

Answer 1

You're use lazy dataTable and this doesn't stay the selection on page change.
You need set the selection param with a type of your collection
Implement getRowKey inside your LazyDataModel and remove rowKey="#{ticket.id}"
Selection with checkbox doesn't need selectionMode="multiple".
This param is only for multiple selection when click on the table row with CTRL is pressed
My sugestion is control your selected data manualy
XHTML file:
<p:dataTable id="#{prefix}List"
value="#{tickets}"
lazy="true"
paginator="true"
var="ticket"
selection="#{ticketForm.selectedTickets}"
emptyMessage="Записи в данной категории отсутствуют">
<p:ajax event="toggleSelect"
listener="#{ticketForm.onAllSelect}" partialSubmit="true"/>
<p:ajax event="rowSelectCheckbox"
listener="#{ticketForm.onSelect}" update=":protocolForm"/>
<p:ajax event="rowUnselectCheckbox"
listener="#{ticketForm.onUnselect}" update=":protocolForm"/>
<p:ajax event="rowSelect"
listener="#{ticketForm.onSelect}" update=":protocolForm"/>
<p:ajax event="rowUnselect"
listener="#{ticketForm.onUnselect}" update=":protocolForm"/>
<p:column selectionMode="multiple" style="width:40px; text-align:center" />
<!--other p:columns-->
</p:dataTable>
Managed bean:
public void onRowSelect(SelectEvent event) {
if (event != null && event.getObject() != null &&
event.getObject() instanceof Ticket) {
if (selectedTickets== null) {
selectedTickets= new ArrayList<Ticket>();
}
if (!selectedTickets.contains((Ticket) event.getObject())) {
selectedTickets.add((Ticket) event.getObject());
}
}
}
public void onRowUnselect(UnselectEvent event) {
if (event != null && event.getObject() != null &&
event.getObject() instanceof Ticket &&
selectedTickets != null && selectedTickets.contains((Ticket) event.getObject())) {
selectedTickets.remove((Ticket) event.getObject());
}
}
public void onAllRowsSelect(ToggleSelectEvent event) {
//This is the trick, you don't need receive a collection
if (event.isSelected()) {
selectedTickets = ticketService.getAllTickets();
} else {
selectedTickets = new ArrayList<Ticket>();
}
}
LazyDataModel implemention of getRowKey method:
public class LazyPragaModel extends LazyDataModel<Ticket> implements Serializable {
private TicketService ticketService;
private static final long serialVersionUID = 1L;
public LazyPragaModel(TicketService ticketService) {
this.ticketService= ticketService;
}
#Override
public Object getRowKey(Ticket ticket) {
return ticket!= null ? ticket.getId() : null;
}
#Override
public Praga getRowData(String rowKey) {
List<Ticket> tickets = (List<Ticket>) getWrappedData();
for (Ticket ticket: tickets) {
if (ticket.getId().toString().endsWith(rowKey)) {
return ticket;
}
}
return null;
}
#Override
public List<Ticket> load(int first, int pageSize, String sortField,
SortOrder sortOrder, Map<String, Object> filters) {
setRowCount(ticketService.countLazyRecords(filters).intValue());
List<Ticket> tickets = ticketService.listLazyRecords(first, pageSize,
sortField, sortOrder.name(), filters);
return tickets;
}
}
Sugestion for your service. Generic methods for lazy dataTables:
public List<T> listLazyRecords(int first, int pageSize, String sortField,
String sortOrder, Map<String, Object> filters) {
sortOrder = sortOrder != null ? sortOrder.contains("ASC") ? "ASC" :
sortOrder.contains("DESC") ? "DESC" : null : null;
String query = " FROM " + getType().getSimpleName() + " t " +
(filters.size() > 0 ? buildLazyFilters(filters) : "") +
(sortOrder != null ? " ORDER BY " + sortField + " " + sortOrder : "");
return getManager().createQuery(query, getType())
.setFirstResult(first).setMaxResults(pageSize).getResultList();
}
public Long countLazyRecords(Map<String, Object> filters) {
String query = "SELECT COUNT(x) FROM " + getType().getSimpleName() +
" x " + (filters.size() > 0 ? buildLazyFilters(filters) : "");
return getManager().createQuery(query).getSingleResult();
}
private String buildLazyFilters(Map<String, Object> filters) {
StringBuilder filterBuild = new StringBuilder("WHERE ");
for (Map.Entry<String, Object> filter : filters.entrySet()) {
if (filter.getValue().toString().chars().allMatch(Character::isDigit)) {
filterBuild.append("( " + filter.getKey() + " = " +
filter.getValue() + " OR ");
}
filterBuild.append(filter.getKey() + " LIKE '%" +
filter.getValue().toString() + "%'");
filterBuild.append(filter.getValue().toString().chars()
.allMatch(Character::isDigit) ? ") ": "");
filterBuild.append(!filters.values().toArray()[filters.size() - 1]
.equals(filter.getValue()) ? " AND " : "");
}
return filterBuild.toString();
}

Answer 2

I think you are missing some things on the datatable.
Showcase: https://www.primefaces.org/showcase/ui/data/datatable/selection.xhtml
You need to add selectionMode=multiple and a selection=collection to gather the selected rows like...
<p:dataTable id="multipleDT"
var="car"
value="#{dtSelectionView.cars4}"
selectionMode="multiple"
selection="#{dtSelectionView.selectedCars}"
rowKey="#{car.id}">
Whenever you select a row or row(s) the #{dtSelectionView.selectedCars} collection will be filled with the selected rows automatically.