h:selectOneMenu 中的 f:ajax 监听器方法没有执行 [英] The f:ajax listener method in h:selectOneMenu is not executed
问题描述
页面在托管 bean 中使用适当的值正确生成，但是这两个 h:selectOneMenus 中的 ajax 事件不起作用.没有调用侦听器.错误必须在标签内的某个地方，但我没有看到.
The page is generated correctly with appropriate values in managed bean, but ajax events in these two h:selectOneMenus don't works. Listener is not called. An error has to be somewhere within tags, but I don't see it.
<f:view>
<h:form>
<h:messages />
<h:panelGrid columns="3">
<h:outputLabel value="Choose your faculty: *" for="faculties" />
<h:selectOneMenu id="faculties" value="#{registrateStudent.selectedFaculty}" >
<f:ajax event="change" listener="#{registrateStudent.genSpecializations}" execute="faculties" render="specializations" />
<f:selectItems value="#{registrateStudent.listFaculty}" var="curFac" itemLabel="#{curFac.name}" itemValue="#{curFac}" />
</h:selectOneMenu>
<h:message id="message_faculties" for="faculties" />
<h:outputLabel value="Choose your specialization: *" for="specializations" />
<h:selectOneMenu id="specializations" value="#{registrateStudent.selectedSpecialization}" >
<f:selectItems value="#{registrateStudent.listSpecialization}" var="curSpec" itemLabel="#{curSpec.name}" itemValue="#{curSpec}"/>
</h:selectOneMenu>
<h:message id="message_specializations" for="specializations" />
托管 Bean:
@ManagedBean(name = "registrateStudent")
@ViewScoped
public class RegistrateStudent {
private Faculty selectedFaculty;
private List<Faculty> listFaculty;
private Specialization selectedSpecialization;
private List<Specialization> listSpecialization;
private boolean showSpecialization = false;
/** Creates a new instance of RegistrateStudent */
public RegistrateStudent() {
users = new Users();
System.out.println("poaposd1");
student = new Student();
}
@PostConstruct
public void init() {
listFaculty = ff.findAll();
if (listFaculty != null) {
selectedFaculty = listFaculty.get(0);
listSpecialization = sf.findByFaculty(selectedFaculty.getIdFaculty());
if (listSpecialization != null) {
selectedSpecialization = listSpecialization.get(0);
}
else {}
} else {}
}
public void genSpecializations(AjaxBehaviorEvent event) {
if (sf.findByFaculty(selectedFaculty.getIdFaculty()) != null) {
this.showSpecialization = true;
} else {
JsfUtil.addSuccessMessage("faculties", "We don't have specializations for such faculty");
}
}
}
更新:
我发现了一些有趣的事情:
I've found out a few interesting things:
render 属性中的错误值不会被注意到，但 event 属性的错误值会产生错误.
<f:ajax> tag doesn't work at <h:link>, <h:selectOneMenu>, <h:button>, <h:commandButton>. In this cases incorrect values in render attribute is not noticed, but incorrect value of event attribute generate an error.
推荐答案
jsf.js 文件包含在 HTML .它包含执行 JSF ajax 魔术的所有 JS 函数.
The <f:ajax> requires jsf.js file being included in the HTML <head>. It contains all JS functions for doing the JSF ajax magic.
要实现这一点，请确保您在主模板中使用 .然后 JSF 将自动包含必要的
