在更改h:selectOneMenu时更新其他输入组件的值 [英] Update value of other input components on change of h:selectOneMenu

问题描述

我有一个JSF 2.2表单，其中包含一个<h:selectOneMenu>，输入和4个用于调用CRUD方法的按钮.为了实现绑定，我使用了valueChangeListener，以便当我从<h:selectOneMenu>中选择id时，我调用了一种方法，该方法更新链接到输入的对象.问题在于输入内容不会改变其值.

表格

<h:selectOneMenu value="#{avocatBurController.numProf}"
                 valueChangeListener="#{avocatBurController.handelValueCahnge}" onchange="submit()">
    <f:selectItems value="#{avocatBurController.lstAvocatbureau}" var="avcBur"
                   itemValue="#{avcBur.avocat.numProf}" itemLabel="#{avcBur.avocat.nom}" />
</h:selectOneMenu>

<h:inputText value="#{avocatBurController.avc.prenom}" />
<h:inputText value="#{avocatBurController.avc.nom}" />
...

ManagedBean

    public void handelValueCahnge(ValueChangeEvent event) {
        String numProf = (String) event.getNewValue();
        AvocatBurDao avcBurDao = new AvocatBurDao();
        avcBur = avcBurDao.getAvocatBur(numProf);
        avc = avcBur.getAvocat();
        System.out.println(avc.getNom());
    }

avc.getNom()包含一个值，但输入不包含.

解决方案

valueChangeListener是用于在更改当前输入时更新其他输入组件的值的工作的错误工具.有很多方法，但是它们是基于在不存在ajax的黑暗JSF 1.x时代发明的.

由于您已经在使用JSF 2.x，因此请立即使用ajax.

<h:selectOneMenu value="#{avocatBurController.numProf}">
    <f:selectItems value="#{avocatBurController.lstAvocatbureau}" var="avcBur"
                   itemValue="#{avcBur.avocat.numProf}" itemLabel="#{avcBur.avocat.nom}" />
    <f:ajax listener="#{avocatBurController.handleValueChange}" render="@form" />
</h:selectOneMenu>

public void handleValueChange() {
    AvocatBurDao avcBurDao = new AvocatBurDao();
    avcBur = avcBurDao.getAvocatBur(numProf);
    avc = avcBur.getAvocat();
}

另请参见:

• 何时使用valueChangeListener或f:ajax监听器?

I have a JSF 2.2 form that contains one <h:selectOneMenu>, inputs and 4 buttons to call CRUD methods. In order to achieve the binding, I used a valueChangeListener so that when I chose an id from the <h:selectOneMenu>, I call a method which updates the object linked to the inputs. The problem is that the inputs don't change their value.

The form

<h:selectOneMenu value="#{avocatBurController.numProf}"
                 valueChangeListener="#{avocatBurController.handelValueCahnge}" onchange="submit()">
    <f:selectItems value="#{avocatBurController.lstAvocatbureau}" var="avcBur"
                   itemValue="#{avcBur.avocat.numProf}" itemLabel="#{avcBur.avocat.nom}" />
</h:selectOneMenu>

<h:inputText value="#{avocatBurController.avc.prenom}" />
<h:inputText value="#{avocatBurController.avc.nom}" />
...

ManagedBean

    public void handelValueCahnge(ValueChangeEvent event) {
        String numProf = (String) event.getNewValue();
        AvocatBurDao avcBurDao = new AvocatBurDao();
        avcBur = avcBurDao.getAvocatBur(numProf);
        avc = avcBur.getAvocat();
        System.out.println(avc.getNom());
    }

avc.getNom() contains a value but the inputs don't.

解决方案

The valueChangeListener is the wrong tool for the job of updating the values of other input components on change of the current input. There are ways, but they are based on hacks/tricks invented during the dark JSF 1.x era when ajax didn't exist.

As you're already on JSF 2.x, just use ajax right away.

<h:selectOneMenu value="#{avocatBurController.numProf}">
    <f:selectItems value="#{avocatBurController.lstAvocatbureau}" var="avcBur"
                   itemValue="#{avcBur.avocat.numProf}" itemLabel="#{avcBur.avocat.nom}" />
    <f:ajax listener="#{avocatBurController.handleValueChange}" render="@form" />
</h:selectOneMenu>

public void handleValueChange() {
    AvocatBurDao avcBurDao = new AvocatBurDao();
    avcBur = avcBurDao.getAvocatBur(numProf);
    avc = avcBur.getAvocat();
}

See also:

• When to use valueChangeListener or f:ajax listener?

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