How to pass parameters to Primefaces LazyDataModel load function - jsf

Question

I have a implemented a lazy loading Datatable with primefaces that implements
load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters)
Now I need to pass parameters from my page to this method (i.e., I have a filter section in my page, the filters are not part of the table, and are independent objects!). My parameters are stored in the page's managed bean.
How can I achieve this?
Thanks!

Answer 1

Make the parameter(s) a property of the bean, and pass them directly to the service that fetches the data from the db (in this example the service is the EJB MyObjFacade myObjFacade):
#ManagedBean
#ViewScoped
public class MyBean {
#EJB
private MyObjFacade myObjFacade;
private LazyDataModel<MyObjType> model; // getter
private MyParameter myParameter;
#PostConstruct
public void init() {
model = new LazyDataModel<MyObjType> () {
#Override
public List<MyObjType> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String, String> filters) {
model.setRowCount(myObjFacade.count(filters, myParameter));
return myObjFacade.getResultList(first, pageSize, sortField, sortOrder, filters, myParameter);
}
};
model.setRowCount(myObjFacade.count(new HashMap<String, String> ()));
}
}
You simply have to provide the service implementing count and getResultList methods.

Answer 2

After many hours searching I finally did it. I leave here my solution for further reference.
//Managed Bean - View
public class DummyLazySearchPageBean {
private LazyDataModel<DummyObject> results;
private String searchFilter;//to simulate search filter
private DummyBusinessClass dummyBusinessClass;
public DummyLazySearchPageBean() {
results = new SearchsLazyLoader();
}
// GETTERS AND SETTERS
#SuppressWarnings("serial")
private final class SearchsLazyLoader extends LazyDataModel<DummyObject> {
#Override
public List<DummyObject> load(int first, int pageSize, String sortField, SortOrder sortOrder, Map<String,Object> filters) {
//Simulate BD model
List<DummyObject> data = new ArrayList<DummyObject>();
dummyBusinessClass = new DummyBusinessClass();
data = dummyBusinessClass.search(searchFilter, 5000);
//rowCount
this.setRowCount(data.size());
//paginate
if(data.size() > pageSize) {
try {
return data.subList(first, first + pageSize);
}
catch(IndexOutOfBoundsException e) {
return data.subList(first, first + (data.size() % pageSize));
}
}
else {
return data;
}
}
}
public final void search(){
results = new SearchsLazyLoader();
}
}

Answer 3

Just Create Constructor of SearchsLazyLoader with parameter input.
This is sample of my code:
package com.mandiri.askes.model.lazy;
import java.util.ArrayList;
import java.util.List;
import java.util.Map;
import org.apache.commons.lang3.StringUtils;
import org.hibernate.Query;
import org.hibernate.Session;
import org.primefaces.model.LazyDataModel;
import org.primefaces.model.SortOrder;
import com.mandiri.askes.model.Participant;
import com.mandiri.askes.utils.CallAble;
import com.mandiri.askes.utils.HibernateUtil;
public class LazyPesertaDataModel extends LazyDataModel<Participant> {
private static final long serialVersionUID = 1L;
private String keyword;
public LazyPesertaDataModel(String keyword) {
if (StringUtils.isNotEmpty(keyword)) {
this.keyword = keyword;
}else{
this.keyword = "";
}
}
/**
* Collect Peserta Badan Usaha as Data Model Primefaces
*
*/
#Override
public List<Participant> load(int first, int pageSize, String sortField,
SortOrder sortOrder, Map<String, String> filters) {
List<Participant> listPesertaBpjs = new ArrayList<Participant>();
listPesertaBpjs = getLazyDataPeserta(first, pageSize, sortField);
this.setRowCount(countAllRecord());
return listPesertaBpjs;
}
/**
* Get Peserta Data using hibernate pagination <b>(Lazy Loading)</b> Technique.
*
* #author Dibrut
* #param firstRecord
* #param maxResult
* #return
*/
#SuppressWarnings("unchecked")
public List<Participant> getLazyDataPeserta(final int firstRecord, final int maxResult, final String sortField) {
return HibernateUtil.doInTransaction(new CallAble<List<Participant>>() {
#Override
public List<Participant> call(Session session) throws Exception {
List<Participant> pesertaList = new ArrayList<Participant>();
String hql = "FROM com.dibrut.learn.model.Participant P"
+ " WHERE P.name LIKE :keyword";
Query query = session.createQuery(hql).setFirstResult(firstRecord).
setMaxResults(maxResult).setString("keyword", "%"+keyword+"%");
pesertaList = query.list();
return pesertaList;
}
});
}
/**
* Count total participant
* #return
* #author Dibrut
*/
public int countAllRecord(){
return HibernateUtil.doInTransaction(new CallAble<Integer>() {
#Override
public Integer call(Session session) throws Exception {
String hql = "FROM com.dibrut.learn.model.Participant P"
+ " WHERE P.name LIKE :keyword";
Long totalPesertaBu = (Long) session.createQuery(hql).
setString("keyword", "%"+ keyword+"%").
uniqueResult();
return totalPesertaBu.intValue();
}
});
}
public String getKeyword() {
return keyword;
}
public void setKeyword(String keyword) {
this.keyword = keyword;
}
}
if you want to search the data, just call the constructor with parameter of your managedBean property. for example you have searchParticipant method in your ManagedBean:
public void searchParticipant() {
this.participantLazyModel = new LazyPesertaDataModel(this.keyword);
}
where the keyword is value of inputText from your page.