I have primefaces datatable which has 4 to 5 input components. One of the input is p:autocomplete. There is a option to add new row through UI, i have added first row later i am trying to add 2nd row whatever value selected in the first row it remains same in the 2nd row. Along with that if i choose different value in the 2nd through autocomplete that value is reflecting for both the rows.
But i would like to retain the value which is selected for first row then i need to retain the 2nd row value differently.
Note: I have used p:selectonemenu inorder to show the values from DB, it has 10000+ records it is taking more time. Due to performance issue i had gone for p:autocomplete
Please see the code
XHTML code- LocationDetails.xhtml
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:t="http://myfaces.apache.org/tomahawk"
xmlns:c="http://java.sun.com/jsp/jstl/core"
xmlns:p="http://primefaces.org/ui">
<h:form id="atcs">
<p:dataTable var="atcscirreq" id="atcscirreqtbl"
value="#{atcsCircuitIdAddressRequestBean.atcsAddressCircuitRequestList}"
binding="#{atcsCircuitIdAddressRequestBean.dataTable}" lazy="true" resizableColumns="true">
<p:column id="locn">
<p:autoComplete id="lcnLst" required="true"
requiredMessage="LocationName is required field"
converter="locationNameAutoCompleteConverter"
completeMethod="#{atcsCircuitIdAddressRequestBean.locationNames}"
var="locn" itemLabel="#{locn.locName}" itemValue="#{locn}"
value="#{atcsCircuitIdAddressRequestBean.locnInfo}"
emptyMessage="No Records Found" maxResults="10"
forceSelection="true">
</p:autoComplete>
</p:column>
</p:dataTable>
<p:commandButton value="Add Another Request" action="# {atcsCircuitIdAddressRequestBean.addNewRequestData}" update="atcscirreqtbl">
</h:form>
ATCSCircuitIdAddressRequestBean.java
package com.bean.request;
public class ATCSCircuitIdAddressRequestBean {
TblTrackLocationinformation locnInfo = new TblTrackLocationinformation();
List<TblTrackLocationinformation> filteredLocations = new ArrayList<TblTrackLocationinformation>();
private List<TblTrackLocationinformation> atcsAddressCircuitRequestList = new ArrayList<TblTrackLocationinformation>();
public List<TblTrackLocationinformation> locationNames(String name) {
List<TblTrackLocationinformation> allLocations = service.getAllLocations;
if (name.trim().equals(""))
return allLocations;
for (int i = 0; i < allLocations.size(); i++) {
TblTrackLocationinformation data = allLocations.get(i);
if (data.getLocName().toString()
.contains(name)
|| data.getLocName().toLowerCase()
.contains(name.toLowerCase())) {
filteredLocations.add(data);
}
}
return filteredLocations;
}
public TblTrackLocationinformation getLocnInfo() {
return locnInfo;
}
public void setLocnInfo(TblTrackLocationinformation locnInfo) {
this.locnInfo = locnInfo;
}
public void addNewRequestData() {
TblTrackLocationInformationdata = new TblTrackLocationInformation();
filteredLocations=new ArrayList<TblTrackLocationinformation>();
atcsAddressCircuitRequestList.add(data);
}
}
TblTrackLocationInformation.java
package com.bean.request;
public class TblTrackLocationInformation{
private String locName;
private Integer locationId;
public String getLocName() {
return locName;
}
public void setLocName(String locName) {
this.locName = locName;
}
public Integer getLocationId() {
return locationId;
}
public void setLocationId(Integer locationId) {
this.locationId = locationId;
}
}
LocationNameAutoCompleteConverter.java
package com.bean.request;
#FacesConverter("locationNameAutoCompleteConverter")
public class LocationNameAutoCompleteConverter implements Converter{
LocationInfoDAO locnDao = new LocationInfoDAOImpl();
#Override
public Object getAsObject(FacesContext arg0, UIComponent arg1, String value) {
return locnDao.getLocationInfoById(Integer.valueOf(value));
}
#Override
public String getAsString(FacesContext arg0, UIComponent arg1, Object value) {
return String.valueOf(((TblTrackLocationinformation) value)
.getLocationId());
}
}
Specifications of the projects are JSF 2.1, Primefaces 5.0,Servlet 2.5
I have searched many links but i did not get answer. I am checking this for past 2 days.
Please help me out !
After long time, i came to know the solution. We need to know when and how to use List with object and List with String.
Have to use
public List<String> locationNames(String name)
instead of
public List<TblTrackLocationinformation> locationNames(String name)
Hi I have built two consecutive dropdowns one being initialized in init() method and the other being populated on the basis on first one's selection.
Command Button is used to use both the selected values for processing, Strange that Setter for the selected values is being called twice(setting blank the second time..as I found out in debugging)..I need understand whyu I am getting blank values?
myPage.xhtml
<p:selectOneMenu id="dbList"
value="#{backingBean.selectedConnection}"
style="width:200px">
<p:ajax listener="#{backingBean.onConnectionChange()}"
update="aliasList" />
<f:selectItem itemLabel="Select" itemValue="#{backingBean.selectedConnection}"
noSelectionOption="false" />
<f:selectItems value="#{backingBean.connectionsTypeList}" />
</p:selectOneMenu>
<p:outputLabel for="aliasList" value="Connection Alias" />
<p:selectOneMenu id="aliasList"
value="#{backingBean.aliasSelected}" style="width:200px">
<f:selectItem itemLabel="Select" itemValue="#{backingBean.aliasSelected}"
noSelectionOption="false"/>
<f:selectItems value="#{backingBean.connectionsList}" />
</p:selectOneMenu>
<p:commandButton value="myButton"
actionListener="#{backingBean.myMethod()}"
id="myButton" />
backingBean.java
#ManagedBean
#ViewScoped
public class BackingBean implements Serializable {
/**
*
*/
private static final long serialVersionUID = 1L;
private ArrayList<String> connectionsList;
private String aliasSelected;
private String selectedConnection;
private ArrayList<String> connectionsTypeList;
#PostConstruct
public void init() {
// Initialize the connection alias drop down here
this.connectionsTypeList = getConnectionTypeList();
this.connectionsList=new ArrayList<String>();
}
public void onConnectionChange() {
System.out.println("In Connection Change, populating aliases");
getConnectionDBList();
}
public String getAliasSelected() {
return aliasSelected;
}
//Dont know why this is called twice on button click and second time value set is blank
public void setAliasSelected(String aliasSelected) {
this.aliasSelected = aliasSelected;
}
public ArrayList<String> getConnectionsList() {
return connectionsList;
}
public void setConnectionsList(ArrayList<String> connectionsList) {
this.connectionsList = connectionsList;
}
public String getSelectedConnection() {
return selectedConnection;
}
public void setSelectedConnection(String selectedConnection) {
this.selectedConnection = selectedConnection;
}
public ArrayList<String> getConnectionsTypeList() {
return connectionsTypeList;
}
public void setConnectionsTypeList(ArrayList<String> connectionsTypeList) {
this.connectionsTypeList = connectionsTypeList;
}
public void myMethod() {
System.out.println("selected Alias is "+aliasSelected);
System.out.println("selected connection is "+selectedConnection);
}
}
New to primefaces,please help
Answer to this :"setting blank the second time..as I found out in debugging"
This is happening because I realized I was pointing the same property to two ui components..as in..two dropdowns in the same page were linked to the same property of the backing bean..Sillyh Mistake..hence the second call to the setter..with Blank values..as it was not initialized for the second UI Component
My composite components share values stored in StateHelper when placed inside PrimeFaces DataTable. The most of examples about keeping component state that I've seen suggest to use getStateHelper().put()/eval() methods of UINamingContainer. I do use these methods but without luck. How to do that properly? (currently I use workaround described in the end of this post)
To illustrate the issue I've created click counter based on PrimeFaces commandLink component. In the example below two counters that are outside of dataTable work as expected. But all counters that appear inside dataTable share the same counter value (clicking on any one of them continues common value).
Update:
I've figured out that to allow sorting (for example) to work correctly inside datatable I need to bind my component to certain raw somehow. And "shared" state helper allows to do exactly that. So now I specify row key as an attribute and have updated methods to store state. There is no question if this way is correct.
Update for counterLink.xhtml:
<composite:interface componentType="CounterLink2Component">
<composite:attribute name="key" type="java.io.Serializable"/>
</composite:interface>
And CounterLinkComponent.java now is:
#FacesComponent("CounterLinkComponent")
public class CounterLinkComponent extends UINamingContainer {
private enum PropertyKeys {
COUNTER_VALUE
}
public void count() {
storeInstanceValue(PropertyKeys.COUNTER_VALUE.toString(), getCounterValue() + 1);
}
public Integer getCounterValue(){
return (Integer) evalInstanceValue(PropertyKeys.COUNTER_VALUE.toString(), 0);
}
private Serializable getKeyAttr() {
return (Serializable) getAttributes().get("key");
}
private void storeInstanceValue(String key, Object value) {
Serializable subkey = getKeyAttr();
if (subkey == null) {
getStateHelper().put(key, value);
} else {
getStateHelper().put(subkey, key, value);
}
}
private Object getInstanceValue(String key) {
Serializable subkey = getKeyAttr();
if (subkey == null) {
return getStateHelper().eval(key);
} else {
return ((Map) getStateHelper().eval(subkey, Collections.emptyMap())).get(key);
}
}
private Object evalInstanceValue(String key, Object _default) {
Object result = getInstanceValue(key);
return result != null ? result : _default;
}
}
Original example:
Primefaces 5.0, Glassfish 4.
counterLink.xhtml:
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:composite="http://java.sun.com/jsf/composite"
xmlns:p="http://primefaces.org/ui">
<composite:interface componentType="CounterLinkComponent">
</composite:interface>
<composite:implementation>
<p:commandLink action="#{cc.count()}" partialSubmit="true" update="#this">
<h:outputText value="#{cc.counterValue}"/>
</p:commandLink>
</composite:implementation>
</html>
CounterLinkComponent.java:
import javax.faces.component.FacesComponent;
import javax.faces.component.UINamingContainer;
import java.io.Serializable;
#FacesComponent("CounterLinkComponent")
public class CounterLinkComponent extends UINamingContainer {
private enum PropertyKeys {
COUNTER_VALUE
}
public void count() {
getStateHelper().put(PropertyKeys.COUNTER_VALUE, getCounterValue() + 1);
}
public Integer getCounterValue(){
return (Integer) getStateHelper().eval(PropertyKeys.COUNTER_VALUE, 0);
}
}
Usage example:
<h:form>
<p:panelGrid columns="1">
<cmp:counterLink/>
<cmp:counterLink/>
<p:dataTable var="item" value="#{counterLinkStoreBean.itemList}">
<p:column headerText="Name">
#{item.name}
</p:column>
<p:column headerText="Counter">
<cmp:counterLink/>
</p:column>
</p:dataTable>
</p:panelGrid>
</h:form>
Backing bean for this example (just creates several items):
#Named
#ViewScoped
public class CounterLinkStoreBean implements Serializable {
private List<Item> itemList;
#PostConstruct
private void init() {
itemList = new ArrayList<Item>();
itemList.add(new Item("Test 1"));
itemList.add(new Item("Test 2"));
itemList.add(new Item("Test 3"));
}
public List<Item> getItemList() {
return itemList;
}
public static class Item {
private final String name;
public Item(String name) {
this.name = name;
}
public String getName() {
return name;
}
}
}
In my case I can use workaround storing values in a map with component clientId as a secondary key:
private void storeInstanceValue(Serializable key, Object value) {
getStateHelper().put(key, getClientId(), value);
}
private Object getInstanceValue(Serializable key) {
return ((Map)getStateHelper().eval(key, Collections.emptyMap())).get(getClientId());
}
Is there more natural solution?
I have a datatable where huge data sets need to be displayed.So i decided to go with primefaces live scrolling.I also got to know that to improve datatable performance with huge data sets we need to implement lazy loading.With reference to the primefaces showcase example
here,what i observed that there in the statement
, a LazyDataModel needs to be implemented to query the datasource when pagination, sorting, filtering or live scrolling happens
live scrolling is mentioned but i cannot see the code to handle scrolling.It only has the code to handle sorting,filtering,row count and pagination.Can someone please clarify my confusion if both live scolling and lazy datamodel implementation are compatible with each other or should i add some code to handle live scrolling also.
It works exactly the same as if you were having a pagination.
Here's a small example:
xhtml
<p:dataTable var="user"
value="#{bean.lazyDataModel}"
scrollRows="20"
liveScroll="true"
scrollHeight="500"
lazy="true"
scrollable="true">
<p:column headerText="name">
<h:outputText value="#{user.name}" />
</p:column>
</p:dataTable>
Bean
#ManagedBean
#ViewScoped
public class Bean {
private LazyDataModel<User> lazyDataModel;
#EJB
UserEJB userEJB;
#PostConstruct
public void init() {
lazyDataModel = new LazyUserModel(userEJB);
}
public LazyDataModel<User> getLazyDataModel() {
return lazyDataModel;
}
public void setLazyDataModel(LazyDataModel<User> lazyDataModel) {
this.lazyDataModel = lazyDataModel;
}
//setters and getters for userEJB
}
LazyUserModel
public class LazyUserModel extends LazyDataModel<User> {
private Integer findAllCount;
#EJB
private UserEJB userEJB;
public LazyUserModel(UserEJB userEJB) {
this.userEJB = userEJB;
}
#Override
public List<User> load(int first, int pageSize, String sortField, SortOrder sortOrder,
Map<String, String> filters) {
List<User> data = new ArrayList<User>();
// pageSize is scrollRows="20" in the datatable
data = userEJB.findAll(first, pageSize);
// findAll is using query.setFirstResult(first).setMaxResults(pageSize).getResultList()
// rowCount
if (findAllCount == null) {
findAllCount = userEJB.findAllCount();
this.setRowCount(findAllCount);
}
return data;
}
}
Hope this helps.
Looks like there's a new attribute for it in 6.1, liveScroll="true"
https://github.com/primefaces/primefaces/issues/2105
My problem is that after I've selected a few items on the 1st page, if I paginate to another page and come back, my initial selections are not shown. I've tried to implement the SelectableDataModel as well as using the rowKey attribute but the problem persists.
This is my test bean:
#ManagedBean
#ViewScoped
public class MrBean {
private List<Item> chosenItems;
private LazyDataModel lazyModel;
#PostConstruct
public void prepareTest() {
this.lazyModel = new LazyItemDataModel();
}
public void countItems() {
System.out.println("TEST 3: chosenItems's size: " + chosenItems.size());
}
private class LazyItemDataModel extends LazyDataModel<Item> implements SelectableDataModel<Item> {
#Override
public Item getRowData(String rowKey) {
System.out.println("TEST 1: getRowData");
Iterator<Item> iter = ((List<Item>) this.getWrappedData()).iterator();
while (iter.hasNext()) {
Item item = iter.next();
if (item.getId().equals(rowKey)) {
return item;
}
}
return null;
}
#Override
public Object getRowKey(Item item) {
return item.getId();
}
#Override
public List<Item> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map filters) {
System.out.println("TEST 2: load");
// Code to retrieve items from database
}
}
// Getters and Setters
}
This is my test page:
<?xml version='1.0' encoding='UTF-8' ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:p="http://primefaces.org/ui">
<h:head>
<title>Test page</title>
</h:head>
<h:body>
<h:form>
<p:dataTable id="itemTable" var="item" value="#{mrBean.items}" rows="5"
paginator="true" selection="#{mrBean.chosenItems}" lazy="true" >
<p:ajax event="rowSelectCheckbox" listener="mrBean.countItems" />
<p:column selectionMode="multiple" />
<p:column headerText="ID">
<h:outputText value="#{item.id}" />
</p:column>
<p:column headerText="Name">
<h:outputText value="#{item.name}" />
</p:column>
</p:dataTable>
</h:form>
</h:body>
</html>
I'd be very grateful if you could show me what I've done wrong here.
UPDATE: After I added more System.out.println("TEST") to the above code, I observed the following things:
On the console, every time I paginate, TEST 1: getRowData is always printed before TEST 2: load. As a consequence, I believe the method #LazyDataModel.getWrappedData() may return data from the old page. At first, I thought this method's goal was to retrieve the selected rows to highlight on the table. However, if this method is called before load, there's no way it can do the job right?
After I selected the 1st 2 items on the 1st page, on the console, I saw TEST 3: chosenItems's size: 2. If I paginate to the 2nd page and then back to the 1st page, the selections are lost as mentioned. However, if I continued to select another item, on the console, I saw TEST 3: chosenItems's size: 3. Obviously, the chosenItems list still kept my old selections but they're not rendered on the table.
In webPage just add a event for when page switch:
<p:ajax event="page" listener="#{listingBean.updateSelected()}" />
In the listingBean, just save the selected:
private List<Entity> selectedInstances;
private List<Entity> selectedInstancesSaved;
public List<Entity> getSelectedInstances()
{
return selectedInstancesSaved;
}
public void setSelectedInstances(List<Entity> selectedInstances)
{
this.selectedInstances = selectedInstances;
}
public void updateSelected()
{
if (selectedInstances != null && !selectedInstances.isEmpty()) {
for (Entity inst : lazyModel.getDatasource()) {
if (selectedInstances.contains(inst)) {
selectedInstancesSaved.add( inst);
} else {
selectedInstancesSaved.remove( inst);
}
}
}
}
This is because when SelectionFeature is decoded a new list is created.
And if table.getRowData(rowKeys[i]) (related to your LazyDataModel implementation) returns null your old selectıons in the previous page are gone.may try to solve it by changing your LazyDataModel implementation I didn't try these but take a look at this and this
Had the same problem and I think this solution is easier if you have a lot of different tables implementing LazyDataModel.
This is what I did: check if it is lazy first then add currently selected rows to the selectionList.
For primefaces 4.0
1)Override DataTableRenderer
In faces-config.xml
<render-kit>
<renderer>
<component-family>org.primefaces.component</component-family>
<renderer-type>org.primefaces.component.DataTableRenderer</renderer-type>
<renderer-class>com.package.LazyDataTableRenderer</renderer-class>
</renderer>
</render-kit>
And
public class LazyDataTableRenderer extends DataTableRenderer {
static Map<DataTableFeatureKey,DataTableFeature> FEATURES;
static {
FEATURES = new HashMap<DataTableFeatureKey,DataTableFeature>();
FEATURES.put(DataTableFeatureKey.DRAGGABLE_COLUMNS, new DraggableColumnsFeature());
FEATURES.put(DataTableFeatureKey.FILTER, new FilterFeature());
FEATURES.put(DataTableFeatureKey.PAGE, new PageFeature());
FEATURES.put(DataTableFeatureKey.SORT, new SortFeature());
FEATURES.put(DataTableFeatureKey.RESIZABLE_COLUMNS, new ResizableColumnsFeature());
FEATURES.put(DataTableFeatureKey.SELECT, new LazySelectionFeature());
FEATURES.put(DataTableFeatureKey.ROW_EDIT, new RowEditFeature());
FEATURES.put(DataTableFeatureKey.CELL_EDIT, new CellEditFeature());
FEATURES.put(DataTableFeatureKey.ROW_EXPAND, new RowExpandFeature());
FEATURES.put(DataTableFeatureKey.SCROLL, new ScrollFeature());
}
#Override
public void decode(FacesContext context, UIComponent component) {
DataTable table = (DataTable) component;
for(Iterator<DataTableFeature> it = FEATURES.values().iterator(); it.hasNext();) {
DataTableFeature feature = it.next();
if(feature.shouldDecode(context, table)) {
feature.decode(context, table);
}
}
decodeBehaviors(context, component);
}
}
2)Override SelectionFeature's decode
Updated: edited to allow deselecting
public class LazySelectionFeature extends org.primefaces.component.datatable.feature.SelectionFeature{
#Override
public void decode(FacesContext context, DataTable table) {
String clientId = table.getClientId(context);
Map<String,String> params = context.getExternalContext().getRequestParameterMap();
String selection = params.get(clientId + "_selection");
if(table.isSingleSelectionMode())
decodeSingleSelection(table, selection);
else
decodeMultipleSelection(context, table, selection);
}
void decodeSingleSelection(DataTable table, String selection) {
if(ComponentUtils.isValueBlank(selection))
table.setSelection(null);
else
table.setSelection(table.getRowData(selection));
}
void decodeMultipleSelection(FacesContext context, DataTable table, String selection) {
Class<?> clazz = table.getValueExpression("selection").getType(context.getELContext());
boolean isArray = clazz.isArray();
if(!isArray && !List.class.isAssignableFrom(clazz)) {
throw new FacesException("Multiple selection reference must be an Array or a List for datatable " + table.getClientId());
}
if(ComponentUtils.isValueBlank(selection)) {
if(isArray) {
table.setSelection(Array.newInstance(clazz.getComponentType(), 0));
}
else {
table.setSelection(new ArrayList<Object>());
}
}
else {
String[] rowKeys = selection.split(",");
List<Object> selectionList = new ArrayList<Object>();
boolean lazy=table.isLazy();
if (lazy) {
List<String> currentRowKeys = new ArrayList<String>(Arrays.asList(rowKeys));
if (table.getSelection() != null) {
List<Object> alreadySelected = (List<Object>) table.getSelection();
for (Object object : alreadySelected) {//For deselecting
Object rowKeyFromModel = table.getRowKeyFromModel(object);
if (currentRowKeys.contains(rowKeyFromModel)) {
selectionList.add(object);
currentRowKeys.remove(rowKeyFromModel);
}
}
}
for (String key : currentRowKeys) {//For selecting
Object rowData = table.getRowData(key);
if (rowData != null && !selectionList.contains(rowData)) {
selectionList.add(rowData);
}
}
}else{
for(int i = 0; i < rowKeys.length; i++) {
Object rowData = table.getRowData(rowKeys[i]);
if(rowData != null)
selectionList.add(rowData);
}
}
if(isArray) {
Object selectionArray = Array.newInstance(clazz.getComponentType(), selectionList.size());
table.setSelection(selectionList.toArray((Object[]) selectionArray));
}
else {
table.setSelection(selectionList);
}
}
}
}
Might not be the best solution but should work, let me know if there is a better way. Hope this helps someone.
Just implement the property bound to selection property of DataTable (selection="#{pageBackingForm.selectedEntityList}") like this and it will work :
private Map<Integer, List<Entity>> selectedEntityListMap = new Hashtable<>();
public List<Entity> getSelectedEntityList() {
return selectedEntityListMap.get(getCurrentEntitySelectionPage());
}
public void setSelectedEntityList(List<Entity> selectedEntityList) {
if (selectedEntityList == null) {
selectedEntityListMap.remove(getCurrentEntitySelectionPage());
return;
}
selectedEntityListMap.put(getCurrentEntitySelectionPage(), selectedEntityList);
}
public Integer getCurrentEntitySelectionPage() {
DataTable dataTable = (DataTable) FacesContext.getCurrentInstance().getViewRoot().findComponent("formId:dataTableId");
return dataTable.getPage();
}
While Bruno's solution works for keeping selections across paginations, it doesn't account for retaining selections on an individual page (i.e. when never changing pages).
This problem can be resolved more simply by using the rowSelectCheckbox and rowUnselectCheckbox ajax events, in addition to having a separate "saved" row list.
JSF:
<p:dataTable selection="#{myBean.selectedRows}" ... >
<p:ajax event="rowSelectCheckbox" process="#this" listener="#{myBean.onSelectRow}" />
<p:ajax event="rowUnselectCheckbox" process="#this" listener="#{myBean.onUnselectRow}" />
<p:column selectionMode="multiple" ... />
...
</p:dataTable>
Backing Bean:
private List<MyRowClass> selectedRows;
private List<MyRowClass> selectedRowsSaved;
...
public void onSelectRow(SelectEvent event){
MyRowClass row = (MyRowClass) event.getObject();
selectedRowsSaved.add(row);
}
public void onUnselectRow(UnselectEvent event){
MyRowClass row = (MyRowClass) event.getObject();
selectedRowsSaved.remove(row);
}
public List<MyRowClass> getSelectedRows(){
return selectedRowsSaved;
}
public void setSelectedRows(List<MyRowClass> selectedRows){
this.selectedRows = selectedRows;
}
This way the list of saved rows is always kept up to date without needing a "page" ajax event.
I had the same problem with my data table. Although my case is a bit different because I am using selectBooleanCheckbox instead. I found a simple solution that works for me. It hit me when you said "old selection are not rendered in the table".
strap the checkbox with a a4j:support event
code:
<h:selectBooleanCheckbox value="#{batch.toPortfolio}">
<a4j:support event="onchange" />
</h:selectBooleanCheckbox>