更新渲染组件以更新另一个组件 [英] update of a render component that updates another component
本文介绍了更新渲染组件以更新另一个组件的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
我有一个无法解决的问题.我有xhtml页面:
I have a problem that i can't solve. I have my xhtml page:
问题是我有一个表格，我在其中插入姓名并选择旅行的地点.它呈现一个外部面板"Volo"，其中selectionMenu会根据所选位置使用从DB获得的一些值进行更新.接下来，我想从Volo选择中获取一个值，并用ID ="HE"(称为HotelEsc的一个)更新另一个面板. 我在"Volo"中的selectionMenu上遇到了麻烦，因为我无法从中获取价值.始终给出NullPointException错误.可能的问题是，我试图了解更新和渲染的工作方式，并且对这些操作有误解.希望对您有所帮助谢谢您.
The problem is that i have a form where i insert the name and select the location of a travel. It renders an external panel "Volo" where the selectionMenu is updated with some values got from DB based on location selected. Next i want to get a value from Volo selection and update the another panel with ID="HE"(is the one called HotelEsc). I'm in trouble with the selectionMenu in "Volo" because i can't get the value into it. Always gives an NullPointException error. Probably the problem is that i'm trying to understand how Update and render work and i am mistaking something about these operations. Hope on your help thank you.
xhtml的代码:
<!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:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<h:head>
<title>Add a Default Package</title>
</h:head>
<h:body>
<h:form id="form">
<p:panel header="DefaultPackage Form">
<h:panelGrid columns="3" id="regGrid">
<h:outputLabel for="Name">Name:</h:outputLabel>
<p:inputText id="Name"
value="#{addDefaultPackageBean.defpackDTO.name}" />
<p:message for="Name" />
<h:outputLabel for="location">Locations Available:</h:outputLabel>
<h:selectOneMenu for="location"
value="#{addDefaultPackageBean.defpackDTO.location}">
<f:ajax listener="#{addDefaultPackageBean.Search()}" render="Volo" />
<f:selectItems id="location"
value="#{addDefaultPackageBean.availableLocations}" />
</h:selectOneMenu>
</h:panelGrid>
</p:panel>
<p:panel header="Voli Disponibili per la location selezionata"
id="Volo">
<h:outputLabel for="Fly">Volo:</h:outputLabel>
<h:selectOneMenu for="Fly" value="#{addDefaultPackageBean.fly}">
<f:selectItems id="Fly" value="#{addDefaultPackageBean.elelisfly}"
var="ElementDTO" itemValue="#{ElementDTO.name}"
itemLabel="#{ElementDTO.name}" />
</h:selectOneMenu>
<p:commandButton action="#{addDefaultPackageBean.sel()}" value="HE" render=":form,:form:regularGrid,:form:Volo" update=":form:Volo" process="form:regGrid,@this"></p:commandButton>
</p:panel>
<p:panel header="HotelEsc" id="HotelEscursioni">
<h:panelGrid columns="3" id="regularGrid">
<h:outputLabel for="Hotel">Hotel:</h:outputLabel>
<h:selectOneMenu for="Hotel" value="#{addDefaultPackageBean.hotel}">
<f:selectItems id="Hotel"
value="#{addDefaultPackageBean.elelishotel}" var="ElementDTO"
itemValue="#{ElementDTO.name}" itemLabel="#{ElementDTO.name}" />
</h:selectOneMenu>
<p:message for="Hotel" />
<h:outputLabel for="Escursion">Escursioni:</h:outputLabel>
<f:facet name="header">Clicca su view per vedere i dettagli</f:facet>
<p:dataTable id="Escursion" var="esc"
value="#{addDefaultPackageBean.elelisescursion}"
rowKey="#{esc.name}"
selection="#{addDefaultPackageBean.selectedEscursions}"
selectionMode="multiple">
<p:column headerText="Nome"> #{esc.name} </p:column>
<p:column headerText="Costo"> #{esc.cost} </p:column>
<p:column headerText="Data Iniziale"> #{esc.startingDate} </p:column>
<p:column headerText="Data Fine"> #{esc.endingDate} </p:column>
<f:facet name="footer">
</f:facet>
</p:dataTable>
</h:panelGrid>
</p:panel>
</h:form>
</h:body>
</html>
相关bean的代码:
package beans;
import java.awt.Event;
import java.io.Serializable;
import java.util.ArrayList;
import javax.annotation.PostConstruct;
import javax.ejb.EJB;
import javax.enterprise.context.SessionScoped;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.RequestScoped;
import javax.faces.view.ViewScoped;
import elementManagement.ElementMgr;
import elementManagementDTO.ElementDTO;
import DefaultPackageManagement.DefaultPackageMgr;
import DefaultPackageManagementDTO.DefaultPackageDTO;
@ManagedBean(name="addDefaultPackageBean") //come viene richiamato
@ViewScoped
public class AddDefaultPackageBean{
/**
*
*/
@EJB
private DefaultPackageMgr defpackMgr;
private DefaultPackageDTO defpackDTO;
private ArrayList<ElementDTO> elelisfly;
private ArrayList<ElementDTO> elelishotel;
private ArrayList<ElementDTO> elelisescursion;
private ArrayList<ElementDTO> elelis;
private ElementDTO[] selectedEscursions;
private String fly;
private String hotel;
private boolean flag=true;
private boolean flagdopo=true;
private ArrayList<String> availableLocations;
private ElementDTO flyElem;
@EJB
private ElementMgr elemMgr;
public ElementDTO[] getSelectedEscursions() {
return selectedEscursions;
}
public void setSelectedEscursions(ElementDTO[] selectedEscursions) {
this.selectedEscursions = selectedEscursions;
}
public AddDefaultPackageBean() {
defpackDTO = new DefaultPackageDTO();
}
@PostConstruct
public void init()
{
this.elelisfly=new ArrayList<ElementDTO>();
this.elelishotel=new ArrayList<ElementDTO>();
this.elelisescursion=new ArrayList<ElementDTO>();
this.setElelis(elemMgr.getAllElements());
this.availableLocations=new ArrayList<String>();
this.flyElem=new ElementDTO();
for(ElementDTO e:elelis)
{
if (this.availableLocations.contains(e.getLocation())==false)
{
this.availableLocations.add(e.getLocation());
}
}
}
public String add() {
this.AssignElemFlyFromSelection();
this.AssignElemHotelFromSelection();
this.AssignElemEscursionFromSelection();
defpackMgr.save(defpackDTO);
return "/employee/index?faces-redirect=true";
}
public void sel()
{
System.out.print("ehila" );
this.setElelis(this.elemMgr.getAllElementsByLocation(this.defpackDTO.getLocation()));
for(ElementDTO e:elelis)
{
System.out.print("elemento della location Haiti "+e.getName());
}
this.AssignElemFlyFromSelection();
System.out.print(this.fly+"Il volo selezionato per la location è "+this.getFlyElem().getName() );
this.elelisescursion.clear();
this.elelishotel.clear();
for(ElementDTO e:elelis)
{
if(e.getType().equals("Hotel"))
{
System.out.print("ho un hotel tra gli elementi "+e.getName() );
if(e.getStartingDate().after(this.flyElem.getStartingDate())&&((e.getEndingDate().before(this.flyElem.getEndingDate()))))
{
System.out.print("ho un hotel tra gli elementi con le date giuste"+e.getName());
this.getElelishotel().add(e);
}
}
else
{
if(e.getType().equals("Escursion"))
{
if(e.getStartingDate().after(this.flyElem.getStartingDate())&&(e.getEndingDate().before(this.flyElem.getEndingDate())))
{
this.getElelishotel().add(e);
}
}
}
}
this.setFlag(true);
this.setFlagdopo(true);
}
public DefaultPackageDTO getDefpackDTO() {
return defpackDTO;
}
public void setDefpackDTO(DefaultPackageDTO defpackDTO) {
this.defpackDTO = defpackDTO;
}
public ArrayList<ElementDTO> getElelisfly() {
return elelisfly;
}
public void setElelisfly(ArrayList<ElementDTO> elelisfly) {
this.elelisfly = elelisfly;
}
public ArrayList<ElementDTO> getElelishotel() {
return elelishotel;
}
public void setElelishotel(ArrayList<ElementDTO> elelishotel) {
this.elelishotel = elelishotel;
}
public ArrayList<ElementDTO> getElelisescursion() {
return elelisescursion;
}
public void setElelisescursion(ArrayList<ElementDTO> elelisescursion) {
this.elelisescursion = elelisescursion;
}
public String getFly() {
return fly;
}
public void setFly(String fly) {
this.fly = fly;
}
public String getHotel() {
return hotel;
}
public void setHotel(String hotel) {
this.hotel = hotel;
}
private void AssignElemFlyFromSelection()
{
for (ElementDTO elem:this.elelisfly)
{
if(elem.getName().equals(this.fly))
{
this.flyElem=elem;
}
}
}
private void AssignElemHotelFromSelection()
{
for (ElementDTO elem:this.elelishotel)
{
if(elem.getName().equals(this.hotel))
{
this.defpackDTO.getElem().add(elem);
}
}
}
private void AssignElemEscursionFromSelection()
{
for(int i=0;i<selectedEscursions.length;i++)
{
this.defpackDTO.getElem().add(selectedEscursions[i]);
}
}
public void Search(){
String s=defpackDTO.getLocation();
System.out.print("luogo scelto "+s);
this.setElelis(this.elemMgr.getAllElementsByLocation(s));
for(ElementDTO e:elelis)
{
System.out.print("aggiungo volo "+e.getName());
if(e.getType().equals("Flight"))
{
this.getElelisfly().add(e);
System.out.print("aggiungo volo "+e.getName());
}
}
this.setFlag(true);
}
public ArrayList<ElementDTO> getElelis() {
return elelis;
}
public void setElelis(ArrayList<ElementDTO> elelis) {
this.elelis = elelis;
}
public ArrayList<String> getAvailableLocations() {
return availableLocations;
}
public void setAvailableLocations(ArrayList<String> availableLocations) {
this.availableLocations = availableLocations;
}
public Boolean getFlag() {
return flag;
}
public void setFlag(Boolean flag) {
this.flag = flag;
}
public boolean isFlagdopo() {
return flagdopo;
}
public void setFlagdopo(boolean flagdopo) {
this.flagdopo = flagdopo;
}
public ElementDTO getFlyElem() {
return flyElem;
}
public void setFlyElem(ElementDTO flyElem) {
this.flyElem = flyElem;
}
}
推荐答案
经过多次尝试，我了解了渲染/更新的工作原理.我希望这里的xhtml解决方案可以帮助其他有相同问题的人: 必须在要刷新的组件上进行更新(例如，在我的情况下，根据选择中的选定值给出的更新目标)；必须使用流程来指定用于实施该操作的组件.
After lots of attempts, i understood how render/update works. I hope the solution with the xhtml here down helps other people with the same problem: The updates have to be done on the components that you want to refresh(for example in my situation the targets of the updates given from chosen values in selections); process has to be used to specificate which components are used to implement the action.
<!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:f="http://java.sun.com/jsf/core"
xmlns:ui="http://java.sun.com/jsf/facelets"
xmlns:p="http://primefaces.org/ui">
<h:head>
<title>Add a Default Package</title>
</h:head>
<h:body>
<h:form id="form">
<p:outputLabel for="Name">Name:</p:outputLabel>
<p:inputText id="Name"
value="#{addDefaultPackageBean.defpackDTO.name}" />
<p:message for="Name" />
<p:outputLabel for="Location">Locations Available:</p:outputLabel>
<p:selectOneMenu id="Location"
value="#{addDefaultPackageBean.defpackDTO.location}">
<f:selectItems
value="#{addDefaultPackageBean.availableLocations}" />
</p:selectOneMenu>
<p:commandButton action="#{addDefaultPackageBean.Search()}" value="Ciao" render=":form:Volo" update=":form:Volo :form"></p:commandButton>
<p:panel header="Voli Disponibili per la location selezionata"
id="Volo" rendered="#{addDefaultPackageBean.flag}">
<h:panelGrid columns="3" id="voloGrid">
<p:outputLabel for="Volare">Volo:</p:outputLabel>
<p:selectOneMenu for="Volare" value="#{addDefaultPackageBean.fly}">
<f:selectItems id="Volare" value="#{addDefaultPackageBean.elelisfly}"
var="Ciao" itemValue="#{Ciao.name}"
itemLabel="#{Ciao.name}" />
</p:selectOneMenu>
<p:commandButton actionListener="#{addDefaultPackageBean.sel()}" value="hesef" update=":form:voloGrid :form:HotelEscursioni" process=":form:Location,:form:voloGrid,@this"/>
</h:panelGrid>
</p:panel>
<p:panel header="HotelEscurs" id="HotelEscursioni" rendered="#{addDefaultPackageBean.flagdopo}">
<p:outputLabel for="Hotel">Hotel:</p:outputLabel>
<p:selectOneMenu for="Hotel" value="#{addDefaultPackageBean.hotel}">
<f:selectItems id="Hotel"
value="#{addDefaultPackageBean.elelishotel}" var="ElementDTO"
itemValue="#{ElementDTO.name}" itemLabel="#{ElementDTO.name}" />
</p:selectOneMenu>
<p:message for="Hotel" />
<p:dataTable id="Escursion" var="esc"
value="#{addDefaultPackageBean.elelisescursion}"
rowKey="#{esc.name}"
selection="#{addDefaultPackageBean.selectedEscursions}"
selectionMode="multiple">
<p:column headerText="Nome"> #{esc.name} </p:column>
<p:column headerText="Costo"> #{esc.cost} </p:column>
<p:column headerText="Data Iniziale"> #{esc.startingDate} </p:column>
<p:column headerText="Data Fine"> #{esc.endingDate} </p:column>
</p:dataTable>
</p:panel>
</h:form>
</h:body>
</html>
这篇关于更新渲染组件以更新另一个组件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
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