DataList has built-in support to deal with huge datasets. In order to enable lazy loading, a LazyDataModel needs to be implemented to query the datasource when pagination happens. This example uses an in-memory list to mimic a real datasource like a database.
In a real application, loading should be executed with the query built using the information passed to the load method.
Documentation<style type="text/css"> .logo { } .detail { width: 200px; padding-left: 25px; } .command { padding-left: 25px; } ul.ui-datalist-data { padding-inline-start: 0px; } </style> <h:form id="form"> <p:dataList value="#{dtLazyView.lazyModel}" var="car" lazy="true" type="unordered" itemType="none" style="width: 450px" paginator="true" rows="5" rowsPerPageTemplate="5,10,20" pageLinks="5" paginatorTemplate="{CurrentPageReport} {FirstPageLink} {PreviousPageLink} {PageLinks} {NextPageLink} {LastPageLink} {RowsPerPageDropdown}"> <h:panelGrid columns="3" columnClasses="logo,detail"> <p:graphicImage name="demo/images/car/#{car.brand}-big.gif" /> <p:outputPanel> <h:panelGrid columns="2" cellpadding="5"> <h:outputText value="Id:" /> <h:outputText value="#{car.id}" style="font-weight: bold"/> <h:outputText value="Year:" /> <h:outputText value="#{car.year}" style="font-weight: bold"/> <h:outputText value="Color:" /> <h:outputText value="#{car.color}" style="font-weight: bold"/> </h:panelGrid> </p:outputPanel> <p:commandLink update=":form:carDetail" oncomplete="PF('carDialog').show()" title="View Detail"> <h:outputText styleClass="ui-icon pi pi-search" style="margin:0 auto;" /> <f:setPropertyActionListener value="#{car}" target="#{dtLazyView.selectedCar}" /> </p:commandLink> </h:panelGrid> </p:dataList> <p:dialog header="Car Info" widgetVar="carDialog" modal="true" showEffect="blind" hideEffect="explode" resizable="false"> <p:outputPanel id="carDetail" style="text-align:center;"> <p:panelGrid columns="2" rendered="#{not empty dtLazyView.selectedCar}" columnClasses="label,value"> <f:facet name="header"> <p:graphicImage name="demo/images/car/#{dtLazyView.selectedCar.brand}-big.gif"/> </f:facet> <h:outputText value="Id:" /> <h:outputText value="#{dtLazyView.selectedCar.id}" /> <h:outputText value="Year" /> <h:outputText value="#{dtLazyView.selectedCar.year}" /> <h:outputText value="Color:" /> <h:outputText value="#{dtLazyView.selectedCar.color}" style="color:#{dtLazyView.selectedCar.color}"/> <h:outputText value="Price" /> <h:outputText value="$#{dtLazyView.selectedCar.price}" /> </p:panelGrid> </p:outputPanel> </p:dialog> </h:form>
@Named("dtLazyView") @ViewScoped public class LazyView implements Serializable { private LazyDataModel<Car> lazyModel; private Car selectedCar; @Inject private CarService service; @PostConstruct public void init() { lazyModel = new LazyCarDataModel(service.createCars(200)); } public LazyDataModel<Car> getLazyModel() { return lazyModel; } public Car getSelectedCar() { return selectedCar; } public void setSelectedCar(Car selectedCar) { this.selectedCar = selectedCar; } public void setService(CarService service) { this.service = service; } public void onRowSelect(SelectEvent<Car> event) { FacesMessage msg = new FacesMessage("Car Selected", event.getObject().getId()); FacesContext.getCurrentInstance().addMessage(null, msg); } }
public class Car implements Serializable { public String id; public String brand; public int year; public String color; public int price; public boolean sold; public Car() {} public Car(String id, String brand, int year, String color) { this.id = id; this.brand = brand; this.year = year; this.color = color; } public Car(String id, String brand, int year, String color, int price, boolean sold) { this.id = id; this.brand = brand; this.year = year; this.color = color; this.price = price; this.sold = sold; } public String getId() { return id; } public void setId(String id) { this.id = id; } public String getBrand() { return brand; } public void setBrand(String brand) { this.brand = brand; } public int getYear() { return year; } public void setYear(int year) { this.year = year; } public String getColor() { return color; } public void setColor(String color) { this.color = color; } public int getPrice() { return price; } public void setPrice(int price) { this.price = price; } public boolean isSold() { return sold; } public void setSold(boolean sold) { this.sold = sold; } @Override public int hashCode() { int hash = 7; hash = 59 * hash + (this.id != null ? this.id.hashCode() : 0); return hash; } @Override public boolean equals(Object obj) { if (obj == null) { return false; } if (getClass() != obj.getClass()) { return false; } final Car other = (Car) obj; if ((this.id == null) ? (other.id != null) : !this.id.equals(other.id)) { return false; } return true; } }
@Named @ApplicationScoped public class CarService { private final static String[] colors; private final static String[] brands; static { colors = new String[10]; colors[0] = "Black"; colors[1] = "White"; colors[2] = "Green"; colors[3] = "Red"; colors[4] = "Blue"; colors[5] = "Orange"; colors[6] = "Silver"; colors[7] = "Yellow"; colors[8] = "Brown"; colors[9] = "Maroon"; brands = new String[10]; brands[0] = "BMW"; brands[1] = "Mercedes"; brands[2] = "Volvo"; brands[3] = "Audi"; brands[4] = "Renault"; brands[5] = "Fiat"; brands[6] = "Volkswagen"; brands[7] = "Honda"; brands[8] = "Jaguar"; brands[9] = "Ford"; } public List<Car> createCars(int size) { List<Car> list = new ArrayList<Car>(); for(int i = 0 ; i < size ; i++) { list.add(new Car(getRandomId(), getRandomBrand(), getRandomYear(), getRandomColor(), getRandomPrice(), getRandomSoldState())); } return list; } private String getRandomId() { return UUID.randomUUID().toString().substring(0, 8); } private int getRandomYear() { return (int) (Math.random() * 50 + 1960); } private String getRandomColor() { return colors[(int) (Math.random() * 10)]; } private String getRandomBrand() { return brands[(int) (Math.random() * 10)]; } private int getRandomPrice() { return (int) (Math.random() * 100000); } private boolean getRandomSoldState() { return (Math.random() > 0.5) ? true: false; } public List<String> getColors() { return Arrays.asList(colors); } public List<String> getBrands() { return Arrays.asList(brands); } }