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Primefaces实用程序，RequestContext，EL函数，对话框框架和搜索表达框架

时间：2020-02-23 14:41:41 　来源:igfitidea点击:

Primefaces是领先的JSF库，它提供了大量组件，并促进了多种实用程序和框架。
本教程将重点介绍最有用的实用程序和框架，并说明如何在开发过程中更有效地利用它们。

Primefaces RequestContext

RequestContext是一个简单的实用程序，可以像FacesContext一样获得，可以用于：

  • 向ajax回调函数添加参数。

  • 帮助进行运行时更新。

  • 执行JavaScript。

在开始探索它之前，让我们先看一下RequestContext API。

MethodDescription
isAjaxRequest()Returns a boolean value if current request is a PrimeFaces ajax request.
addCallBackParam(String name, Object value)Adds parameters to ajax callbacks like oncomplete.
update(String clientId);Specifies component(s) to update at runtime.
execute(String script)Executes script after ajax request completes or on page load.
scrollTo(String clientId)Scrolls to the component with given clientId after ajax request completes.

Primefaces RequestContext –回调参数

有时，您会遇到需要从ajax回调中的支持bean中获取一些值的情况。
回调参数被序列化为JSON，并作为ajax回调中的参数提供，以进行此类访问。

index.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
		xmlns:ui="https://java.sun.com/jsf/facelets"
		xmlns:h="https://java.sun.com/jsf/html"
		xmlns:f="https://java.sun.com/jsf/core"
		xmlns:p="https://primefaces.org/ui">
	<h:head>
		<script name="jquery/jquery.js" library="primefaces"></script>
		<script>
			function handleComplete(xhr,status,args){
				var isValid = args.isValid;
				alert("isValid RequestContext Parameter Passed Is :: "+isValid);
			}
		</script>
	</h:head>
	<h:form>
		<p:commandButton value="Validate" action="#{utilitiesManagedBean.validate}"
			oncomplete="handleComplete(xhr,status,args)"></p:commandButton>
	</h:form>
	</html>

UtilitiesManagedBean.java

package com.theitroad.prime.faces.beans;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

import org.primefaces.context.RequestContext;

@ManagedBean
@SessionScoped
public class UtilitiesManagedBean {
	public String validate(){
		//Acquire Request Context instance
		RequestContext context = RequestContext.getCurrentInstance();
		//Add isValid parameter
		context.addCallbackParam("isValid", true);
		return "";
	}
}

您可以发送任意多个参数，每个参数都将序列化为JSON格式。
这样，您就有机会发送您想要的任何类型的实例(例如Person)并访问其字段，例如args.person.firstname等。

默认情况下，如果验证周期失败，则隐式添加validateationFailed回调参数。

Primefaces RequestContext-运行时更新

通过使用RequestContext实例，您可以有条件地更新页面的组件。
您无法使用命令的update属性有条件地更新组件。
通过使用RequestContext的更新方法，您现在很高兴可以做到这一点。

index2.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form" prependId="false">
	<p:growl id="acceptedMessage"></p:growl>
	<p:growl id="refusedMessage"></p:growl>
	<p:commandButton value="Validate"
		action="#{utilitiesManagedBean.validate}"></p:commandButton>
</h:form>
</html>

UtilitiesManagedBean.java

package com.theitroad.prime.faces.beans;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;

import org.primefaces.context.RequestContext;

@ManagedBean
@SessionScoped
public class UtilitiesManagedBean {
	public String validate(){
		//Initial value for valid boolean
		boolean valid = false;
		//Do some computation
		if(Math.floor(Math.random()*10) % 2 == 0){
			valid = true;
		}
		//Acquire Request Context instance
		RequestContext context = RequestContext.getCurrentInstance();
		//Add isValid parameter
		context.addCallbackParam("isValid", valid);
		//If valid equal true, render accepted message
		if(valid){
			//Add message into your FacesContext
			FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Your request is accepeted ! Congrats"));
			//Acquire RequestContext singleton and update desired components
			RequestContext.getCurrentInstance().update("acceptedMessage");
		}
		//else If valid equal false, render refused message
		if(!valid){
			//Add message into your FacesContext
			FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Your request is refused ! Sorry"));
			//Acquire RequestContext singleton and update desired components
			RequestContext.getCurrentInstance().update("refusedMessage");
		}
		return "";
	}
}

Primefaces RequestContext-执行JavaScript

RequestContext还为您提供了一种在ajax请求完成时执行JavaScript的方法。
与传递回调参数和执行条件JavaScript相比，它更容易。

index3.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form prependId="false">
	<p:commandButton value="Execute JavaScript"
		action="#{utilitiesManagedBean.executeJavaScript}"></p:commandButton>
	<p:dialog widgetVar="acceptedDialog">
		<p:outputLabel value="Accepted"></p:outputLabel>
	</p:dialog>
	<p:dialog widgetVar="refusedDialog">
		<p:outputLabel value="Refused"></p:outputLabel>
	</p:dialog>
</h:form>
</html>

UtilitiesManagedBean.java

package com.theitroad.prime.faces.beans;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;

import org.primefaces.context.RequestContext;

@ManagedBean
@SessionScoped
public class UtilitiesManagedBean {
	public String validate(){
		//Initial value for valid boolean
		boolean valid = false;
		//Do some computation
		if(Math.floor(Math.random()*10) % 2 == 0){
			valid = true;
		}
		//Acquire Request Context instance
		RequestContext context = RequestContext.getCurrentInstance();
		//Add isValid parameter
		context.addCallbackParam("isValid", valid);
		//If valid equal true, render accepted message
		if(valid){
			//Add message into your FacesContext
			FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Your request is accepeted ! Congrats"));
			//Acquire RequestContext singleton and update desired components
			RequestContext.getCurrentInstance().update("acceptedMessage");
		}
		//else If valid equal false, render refused message
		if(!valid){
			//Add message into your FacesContext
			FacesContext.getCurrentInstance().addMessage(null, new FacesMessage("Your request is refused ! Sorry"));
			//Acquire RequestContext singleton and update desired components
			RequestContext.getCurrentInstance().update("refusedMessage");
		}
		return "";
	}

	public String executeJavaScript(){
		//Initial value for valid boolean
		boolean valid = false;
		//Do some computation
		if(Math.floor(Math.random()*10) % 2 == 0){
			valid = true;
		}
		//Hide all of dialogs
		RequestContext.getCurrentInstance().execute("PF('acceptedDialog').hide()");
		RequestContext.getCurrentInstance().execute("PF('refusedDialog').hide()");
		//If valid equal true, render accepted message
		if(valid){
			//Acquire RequestContext singleton and execute wanted JavaScript
			RequestContext.getCurrentInstance().execute("PF('acceptedDialog').show()");
		}
		//else If valid equal false, render refused message
		if(!valid){
			//Acquire RequestContext singleton and execute wanted JavaScript
			RequestContext.getCurrentInstance().execute("PF('refusedDialog').show()");
		}
		return "";
	}
}

Primefaces EL功能

Primefaces提供了内置的EL表达式，在很多情况下都非常有用。
在开始使用EL函数之前，请先看一下EL函数的API。

FunctionDescription
component('id')Returns clientId of the component with provided server id parameter. This function is useful if you need to work with javascript.
widgetVar('id')Provides the widgetVar of a component in PF(";) format.

Primefaces EL功能–组件和WidgetVar

Primefaces提供了一种使用组件标识符或者WidgetVars轻松定位组件的简便方法。

index4.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:outputLabel id="text" value="This component accessed by EL function and it's ID is: #{p:component('text')}"></p:outputLabel>
	<p:dialog id="dlg">
		<p:outputLabel value="Dialog Component"></p:outputLabel>
	</p:dialog>
	<p:separator
	<p:commandButton id="action2" value="Show Dialog" type="button" onclick="#{p:widgetVar('form:dlg')}.show()"></p:commandButton>
</h:form>
</html>

Primefaces异常处理程序

我们在Ajax行为教程中对异常处理程序进行了详细说明。

Primefaces语言环境

我们在日历组件教程中对Primefaces语言环境进行了详细说明。

Primefaces对话框架

对话框框架(DF)用于在运行时动态生成的对话框中打开外部XHTML页面。
这与我们用来显示对话框的旧样式有点不同。
旧方法需要在XHTML页面内定义p：dialog并利用show/hide来控制对话框(显示/隐藏)。
这次，我们将使用DF API，其中将使用编程API在运行时立即创建和销毁对话框。
下面的简单示例向您显示以编程方式创建和销毁的对话框。

faces-config.xml

<?xml version="1.0" encoding="UTF-8"?>
<faces-config xmlns="https://xmlns.jcp.org/xml/ns/javaee"
	xmlns:xsi="https://www.w3.org/2001/XMLSchema-instance"
	xsi:schemaLocation="https://xmlns.jcp.org/xml/ns/javaee https://xmlns.jcp.org/xml/ns/javaee/web-facesconfig_2_2.xsd"
	version="2.2">
	<application>
		<action-listener>org.primefaces.application.DialogActionListener</action-listener>
		<navigation-handler>org.primefaces.application.DialogNavigationHandler</navigation-handler>
		<view-handler>org.primefaces.application.DialogViewHandler</view-handler>
	</application>
</faces-config>

dialogInitiator.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:commandButton value="Show Dialog" action="#{dialogFrameworkManagedBean.showDialog}"></p:commandButton>
</h:form>
</html>

externalXHTML.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:outputLabel value="This XHTML page will be dispalyed/hidden via using of DF API"></p:outputLabel>
</h:form>
</html>

DialogFrameworkManagedBean.java

package com.theitroad.prime.faces.beans;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

import org.primefaces.context.RequestContext;

@ManagedBean
@SessionScoped
public class DialogFrameworkManagedBean {

	public String showDialog(){
		RequestContext.getCurrentInstance().openDialog("externalXHTML");
		return "";
	}
}

您可以提供Optional参数，以帮助您对对话框属性进行其他控制。
以下示例显示了如何为可控制的属性提供参数和数字表。

dialogInitiator.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:commandButton value="Show Dialog - Basic" action="#{dialogFrameworkManagedBean.showDialog}"></p:commandButton>
	<p:commandButton value="Show Dialog - Additional Properties" action="#{dialogFrameworkManagedBean.showDialogWithAdditionalArg}"></p:commandButton>
</h:form>
</html>

externalXHTML.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:outputLabel value="This XHTML page will be dispalyed/hidden via using of DF API"></p:outputLabel>
</h:form>
</html>

DialogFrameworkManagedBean.java

package com.theitroad.prime.faces.beans;

import java.util.HashMap;
import java.util.Map;

import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;

import org.primefaces.context.RequestContext;

@ManagedBean
@SessionScoped
public class DialogFrameworkManagedBean {

	public String showDialog(){
		RequestContext.getCurrentInstance().openDialog("externalXHTML");
		return "";
	}

	public String showDialogWithAdditionalArg(){
		//Fill in properties
		Map<String,Object> properties  = new HashMap<String,Object>();
		properties.put("modal", true);
		properties.put("resizable", true);
		properties.put("draggable", true);
		properties.put("width", 400);
		properties.put("height", 400);
		RequestContext.getCurrentInstance().openDialog("externalXHTML",properties,null);
		return "";
	}

}

在您可能想要提供的所有这些属性下面查找。

NameDefaultTypeDescription
modal0BooleanControls modality of the dialog.
resizable1BooleanWhen enabled, makes dialog resizable.
draggable1BooleanWhen enabled, makes dialog draggable.
widthautoIntegerWidth of the dialog.
heightautoIntegerHeight of the dialog.
contentWidth640IntegerWidth of the dialog content.
contentHeightautoIntegerHeight of the dialog content.
closabletrueBooleanWhether the dialog can be closed or not.

Primefaces对话框架–数据通信

您可以将数据传回到触发该对话框的父页面中。

dataInitiator.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:growl id="growl" showDetail="true" showSummary="true"></p:growl>
	<p:commandButton value="Show Dialog - Basic" action="#{dialogFrameworkManagedBean.showDialog}"></p:commandButton>
	<p:commandButton value="Show Dialog - Additional Properties" action="#{dialogFrameworkManagedBean.showDialogWithAdditionalArg}"></p:commandButton>
	<p:commandButton value="Show Employees Dialog" action="#{dialogFrameworkManagedBean.showEmployeesDialog}">
		<p:ajax event="dialogReturn" listener="#{dialogFrameworkManagedBean.onEmployeeChosen}" update="growl" 
	</p:commandButton>
</h:form>
</html>

employee.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:dataTable value="#{dialogFrameworkManagedBean.employees}" var="employee">
		<p:column headerText="Employee ID">
			<p:outputLabel value="#{employee.employeeId}"></p:outputLabel>
		</p:column>
		<p:column headerText="Employee Name">
			<p:outputLabel value="#{employee.employeeName}"></p:outputLabel>
		</p:column>
		<p:column headerText="Select Employee">
			<p:commandButton icon="ui-icon-search" action="#{dialogFrameworkManagedBean.selectEmployeeFromDialog(employee)}" 
     	</p:column>
	</p:dataTable>
</h:form>
</html>

DialogFrameworkManagedBean.java

package com.theitroad.prime.faces.beans;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;

import org.primefaces.context.RequestContext;
import org.primefaces.event.SelectEvent;

@ManagedBean
@SessionScoped
public class DialogFrameworkManagedBean {
	private List<Employee> employees = new ArrayList<Employee>();

	public List<Employee> getEmployees() {
		return employees;
	}

	public void setEmployees(List<Employee> employees) {
		this.employees = employees;
	}

	public String showDialog(){
		RequestContext.getCurrentInstance().openDialog("externalXHTML");
		return "";
	}

	public String showDialogWithAdditionalArg(){
		//Fill in properties
		Map<String,Object> properties  = new HashMap<String,Object>();
		properties.put("modal", true);
		properties.put("resizable", true);
		properties.put("draggable", true);
		properties.put("width", 400);
		properties.put("height", 400);
		RequestContext.getCurrentInstance().openDialog("externalXHTML",properties,null);
		return "";
	}

	public String showEmployeesDialog(){
		this.employees = new ArrayList<Employee>();
		for(int i = 1 ; i < 10 ; i++){
			Employee employee = new Employee();
			employee.setEmployeeId(i);
			employee.setEmployeeName("Employee"+i);
			employee.setEmployeeAge(String.valueOf(21+i));
			this.employees.add(employee);
		}
		RequestContext.getCurrentInstance().openDialog("employees");
		return "";
	}

	public void selectEmployeeFromDialog(Employee employee) {
      RequestContext.getCurrentInstance().closeDialog(employee);
  }

	public void onEmployeeChosen(SelectEvent event){
		Employee employee = (Employee) event.getObject();
      FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO,
      		"Employee Selected",
      		"Id:" + employee.getEmployeeId()+"\n"+
      		"Name:"+employee.getEmployeeName());
      FacesContext.getCurrentInstance().addMessage(null, message);
	}

	public class Employee {
		private int employeeId;
		private String employeeName;
		private String employeeAge;
		public int getEmployeeId() {
			return employeeId;
		}
		public void setEmployeeId(int employeeId) {
			this.employeeId = employeeId;
		}
		public String getEmployeeName() {
			return employeeName;
		}
		public void setEmployeeName(String employeeName) {
			this.employeeName = employeeName;
		}
		public String getEmployeeAge() {
			return employeeAge;
		}
		public void setEmployeeAge(String employeeAge) {
			this.employeeAge = employeeAge;
		}
	}

}

以下是上面列出的代码的详细说明：

  • 包含触发操作的父页面应提供一个dialogReturn ajax事件。

  • RequestContext.getCurrentInstance()。
    closeDialog已用于按常规方式返回的数据。
    如果您尝试在不返回数据的情况下使用它，则会出现异常。

  • 从jsf 2开始，dataTable组件提供了一种新方法来指定选定的雇员。
    即通过使用选择触发器直接发送选择的员工。

  • p：commandButton和p：commandLink都支持dialogReturn事件。

Primefaces对话框框架–对话框消息

众所周知如何使用标准的FacesContext – addMessage方式将消息添加到视图甚至对话框中。
对话框框架提供了一种将消息添加到打开的对话框中的新方法。
以下示例将帮助您以非传统方式显示您的消息。

employees.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
<h:form id="form">
	<p:dataTable value="#{dialogFrameworkManagedBean.employees}" var="employee">
		<p:column headerText="Employee ID">
			<p:outputLabel value="#{employee.employeeId}"></p:outputLabel>
		</p:column>
		<p:column headerText="Employee Name">
			<p:outputLabel value="#{employee.employeeName}"></p:outputLabel>
		</p:column>
		<p:column headerText="Select Employee">
			<p:commandButton icon="ui-icon-search" action="#{dialogFrameworkManagedBean.selectEmployeeFromDialog(employee)}" 
     	</p:column>
	</p:dataTable>
	<p:commandButton value="Show Message" action="#{dialogFrameworkManagedBean.showMessage}"></p:commandButton>
</h:form>
</html>

DialogFrameworkManagedBean.java

package com.theitroad.prime.faces.beans;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;

import org.primefaces.context.RequestContext;
import org.primefaces.event.SelectEvent;

@ManagedBean
@SessionScoped
public class DialogFrameworkManagedBean {
	private List<Employee> employees = new ArrayList<Employee>();

	public List<Employee> getEmployees() {
		return employees;
	}

	public void setEmployees(List<Employee> employees) {
		this.employees = employees;
	}

	public String showDialog(){
		RequestContext.getCurrentInstance().openDialog("externalXHTML");
		return "";
	}

	public String showDialogWithAdditionalArg(){
		//Fill in properties
		Map<String,Object> properties  = new HashMap<String,Object>();
		properties.put("modal", true);
		properties.put("resizable", true);
		properties.put("draggable", true);
		properties.put("width", 400);
		properties.put("height", 400);
		RequestContext.getCurrentInstance().openDialog("externalXHTML",properties,null);
		return "";
	}

	public String showEmployeesDialog(){
		this.employees = new ArrayList<Employee>();
		for(int i = 1 ; i < 10 ; i++){
			Employee employee = new Employee();
			employee.setEmployeeId(i);
			employee.setEmployeeName("Employee"+i);
			employee.setEmployeeAge(String.valueOf(21+i));
			this.employees.add(employee);
		}
		RequestContext.getCurrentInstance().openDialog("employees");
		return "";
	}

	public void selectEmployeeFromDialog(Employee employee) {
      RequestContext.getCurrentInstance().closeDialog(employee);
  }

	public void onEmployeeChosen(SelectEvent event){
		Employee employee = (Employee) event.getObject();
      FacesMessage message = new FacesMessage(FacesMessage.SEVERITY_INFO,
      		"Employee Selected",
      		"Id:" + employee.getEmployeeId()+"\n"+
      		"Name:"+employee.getEmployeeName());
      FacesContext.getCurrentInstance().addMessage(null, message);
	}

	public String showMessage(){
		RequestContext.getCurrentInstance().showMessageSan Francecolog(new FacesMessage("Message Is Shown"));
		return "";
	}

	public class Employee {
		private int employeeId;
		private String employeeName;
		private String employeeAge;
		public int getEmployeeId() {
			return employeeId;
		}
		public void setEmployeeId(int employeeId) {
			this.employeeId = employeeId;
		}
		public String getEmployeeName() {
			return employeeName;
		}
		public void setEmployeeName(String employeeName) {
			this.employeeName = employeeName;
		}
		public String getEmployeeAge() {
			return employeeAge;
		}
		public void setEmployeeAge(String employeeAge) {
			this.employeeAge = employeeAge;
		}
	}
}
  • 可以使用RequestContext.getCurrentInstance()。
    showMessage(" your_msg")代码将新消息添加到打开的对话框中。

Primefaces搜索表达框架

我们介绍了一些使用搜索表达式框架的教程。
但是值得深入了解以了解更多信息。
核心JSF组件引用仅基于具有基本关键字支持的组件标识符。
Primefaces搜索表达框架提供了服务器端和客户端扩展，从而使引用组件变得更加容易。
让我们查看所有可用于引用可能位于视图中的组件的关键字。

KeywordTypeDescription
@thisStandardCurrent component.
@allStandardWhole view.
@formStandardClosest ancestor form of current component.
@noneStandardNo component.
@namingcontainerPrimeFacesClosest ancestor naming container of current component.
@parentPrimeFacesParent of the current component.
@compositePrimeFacesClosest composite component ancestor.
@child(n)PrimeFacesnth child.
@previousPrimeFacesPrevious sibling.
@nextPrimeFacesNext sibling.
@widgetVar(name)PrimeFacesComponent with given widgetVar.

现在，让我们看一些示例，说明如何利用这些关键字在页面上查找所需组件。

SEF.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
	<h:form>
		<p:growl id="message"></p:growl>
		<p:outputLabel id="output1" value="Enter Username">#{' '}</p:outputLabel><p:inputText id="username" value="#{searchExtensionFramework.username}"></p:inputText>
		<p:separator
		<p:outputLabel id="output2" value="Enter Password">#{' '}</p:outputLabel><p:password id="password" value="#{searchExtensionFramework.password}"></p:password>
		<p:separator
		<p:commandButton value="Reference Message Component"
			action="#{searchExtensionFramework.doAction}"
			process="@this" update="@form:@child(0)"></p:commandButton>
	</h:form>
</html>

SearchExtensionFramework.java

package com.theitroad.prime.faces.beans;

import javax.faces.application.FacesMessage;
import javax.faces.bean.ManagedBean;
import javax.faces.bean.SessionScoped;
import javax.faces.context.FacesContext;

@ManagedBean
@SessionScoped
public class SearchExtensionFramework {
	private String username = "";
	private String password = "";
	
	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	public String doAction(){
		FacesContext.getCurrentInstance().addMessage(null, 
				new FacesMessage("Growl Component Updated and Referenced By Using SEF","Username: "
						+	this.username	+	" :: Password: "	+	password));
		return "";
	}
}

  • 我们先使用@form引用了表单，然后使用@child(0)引用了咆哮组件。

  • @form：@child(0)被称为复合表达式。

SEF.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
	<h:form>
		<p:growl widgetVar="message"></p:growl>
		<p:outputLabel id="output1" value="Enter Username">#{' '}</p:outputLabel><p:inputText id="username" value="#{searchExtensionFramework.username}"></p:inputText>
		<p:separator
		<p:outputLabel id="output2" value="Enter Password">#{' '}</p:outputLabel><p:password id="password" value="#{searchExtensionFramework.password}"></p:password>
		<p:separator
		<p:commandButton value="Reference Message Component"
			action="#{searchExtensionFramework.doAction}"
			process="@this" update="@widgetVar(message)"></p:commandButton>
	</h:form>
</html>

当单独使用@widgetVar时，您将获得相同的结果。

Primefaces搜索表达框架– Primefaces选择器

Primefaces将jQuery Selector API与JSF组件引用模型集成在一起，因此可以使用jQuery Selector API代替基于代码ID的JSF模型来进行引用。

SEF.xhtml

<html xmlns="https://www.w3.org/1999/xhtml"
	xmlns:ui="https://java.sun.com/jsf/facelets"
	xmlns:h="https://java.sun.com/jsf/html"
	xmlns:f="https://java.sun.com/jsf/core"
	xmlns:p="https://primefaces.org/ui">
<h:head>
	<script name="jquery/jquery.js" library="primefaces"></script>
</h:head>
	<h:form>
		<p:growl></p:growl>
		<p:outputLabel id="output1" value="Enter Username">#{' '}</p:outputLabel><p:inputText id="username" value="#{searchExtensionFramework.username}"></p:inputText>
		<p:separator
		<p:outputLabel id="output2" value="Enter Password">#{' '}</p:outputLabel><p:password id="password" value="#{searchExtensionFramework.password}"></p:password>
		<p:separator
		<p:commandButton value="Reference Message Component"
			action="#{searchExtensionFramework.doAction}"
			process="@this" update="@(form:first)"></p:commandButton>
	</h:form>
</html>

  • 当您使用JQuery表达式形式时，您将获得相同的结果。
    假设您的输入具有.myStyle样式；通过使用@(。 myStyle)，您可以指定具有它的组件。

  • 如果您在更新或者过程中使用了@(：input)，则尝试更新或者处理您拥有的所有输入组件。

  • 您可以在Primefaces和jQuery引用技术之间进行组合。

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