java 在 jsf 中通过 ajax 渲染 <h:panelGroup>
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rendering <h:panelGroup> by ajax in jsf
提问by Martin P
I've got this piece of code, which doesn't do exactly what I thought. I try to set property by Ajax and then re-render one component. My .xhtml looks like this
我有这段代码，它并不完全符合我的想法。我尝试通过 Ajax 设置属性，然后重新渲染一个组件。我的 .xhtml 看起来像这样
<h:form>
<h:commandButton value="Render!" >
<f:ajax render=":result" listener="#{eFindUser.findUser}" />
</h:commandButton>
</h:form>
<h:panelGroup id="result" layout="block" rendered="#{eFindUser.responseRendered}" >
This is some text that is supposed to be rendered later
</h:panelGroup>
the backing bean looks like this
支持 bean 看起来像这样
@Named(value = "eFindUser")
@ViewScoped
public class EFindUserManagedBean implements Serializable{
private boolean responseRendered = false;
/**
* Creates a new instance of EFindUserManagedBean
*/
public EFindUserManagedBean() {
}
public void findUser(AjaxBehaviorEvent abe) {
responseRendered = !responseRendered;
System.out.println("finding..... ("+ responseRendered+")" + this);
}
public boolean isResponseRendered() {
return responseRendered;
}
public void setResponseRendered(boolean responseRendered) {
this.responseRendered = responseRendered;
}
}
When I re-click the button, the property is not changed. There is a message in serverlog, which says
当我重新单击按钮时，属性不会改变。服务器日志中有一条消息，上面写着
INFO: finding..... (true)backingbeans.EFindUserManagedBean@5736b751
INFO: finding..... (true)backingbeans.EFindUserManagedBean@23959d6f
Clearly there is some issue with the managed bean as it is created every time there is a request even if it should be view-scoped.
很明显，托管 bean 存在一些问题，因为它在每次有请求时都会创建，即使它应该是视图范围的。
What should I change so the panelgroup(id:"result") could change it's visibility? No richfaces or any other technology allowed.
我应该更改什么才能使 panelgroup(id:"result") 可以改变它的可见性？不允许使用富人脸或任何其他技术。
Thank you very much for your answers
非常感谢您的回答
采纳答案by uzvar
This works for me:
这对我有用：
<ui:composition>
<h:form id="mainForm">
<h:commandButton value="Render!" action="#{eFindUser.findUser}">
<f:ajax event="action" render=":result" />
</h:commandButton>
</h:form>
<h:panelGroup id="result" layout="block" rendered="#{eFindUser.responseRendered}" >
This is some text that is supposed to be rendered later
</h:panelGroup>
</ui:composition>
Bean:
豆角，扁豆：
@ManagedBean
@ViewScoped
public class EFindUser implements Serializable{
private static final long serialVersionUID = -7106162864352727534L;
private boolean responseRendered = false;
public EFindUser() {
}
public void findUser() {
responseRendered = !responseRendered;
System.out.println("finding..... ("+ responseRendered+")" + this);
}
public boolean isResponseRendered() {
return responseRendered;
}
public void setResponseRendered(boolean responseRendered) {
this.responseRendered = responseRendered;
}
}
Take a look on JSF 2.0 + Ajax Hello World Example
回答by Alexandre Lavoie
You can't render dynamically a JSF component that is not rendered all time. The object must exist in the DOM client side. When using rendered="false", the output is not generated server side.
您无法动态呈现并非始终呈现的 JSF 组件。该对象必须存在于 DOM 客户端。使用 render="false" 时，不会在服务器端生成输出。
Change your code like this :
像这样改变你的代码：
<h:form>
<h:commandButton value="Render!" >
<f:ajax render=":result" listener="#{eFindUser.findUser}" />
</h:commandButton>
</h:form>
<h:panelGroup id="result">
<h:panelGroup layout="block" rendered="#{eFindUser.responseRendered}" >
This is some text that is supposed to be rendered later
</h:panelGroup>
</h:panelGroup>
With that, the DOM will always contain something with the id="result".
这样，DOM 将始终包含 id="result" 的内容。
