重复的 ID。日本科学基金会

发布于 2024-08-05 00:25:16 字数 794 浏览 3 评论 0原文

我的 JSF 有问题。谁能说为什么这不起作用？

<h:selectOneListbox
  id="lang" size="5"
  value="#{MbInstitution.node.lang}"
  valueChangeListener="#{MbInstitution.changeLanguage}"
  rendered="#{MbInstitution.view}"
  >
 <a4j:support event="onchange" reRender="shortDesc, fullDesc"/>
 <f:selectItems value="#{MbInstitution.languagesByInstitute}"/>
</h:selectOneListbox>
<h:selectOneListbox
  id="lang" size="5"
  disabled="#{!MbInstitution.managingNew}"
  value="#{MbInstitution.node.lang}"
  rendered="#{!MbInstitution.view}"
  >
 <f:selectItems value="#{MbInstitution.availableLanguages}"/>
</h:selectOneListbox>

它说：“组件 instForm:lang 的重复 ID” 我知道我有 2 个具有相同 Id 的元素，但只有一个元素不渲染时才会渲染。所以，我不认为这会成为问题。其实这根本不是一个大问题，因为我不需要这个id，但是如果我需要的话我该怎么办？

原文

I have a problem with JSF. Can anyone say why this doesn't work?

<h:selectOneListbox
  id="lang" size="5"
  value="#{MbInstitution.node.lang}"
  valueChangeListener="#{MbInstitution.changeLanguage}"
  rendered="#{MbInstitution.view}"
  >
 <a4j:support event="onchange" reRender="shortDesc, fullDesc"/>
 <f:selectItems value="#{MbInstitution.languagesByInstitute}"/>
</h:selectOneListbox>
<h:selectOneListbox
  id="lang" size="5"
  disabled="#{!MbInstitution.managingNew}"
  value="#{MbInstitution.node.lang}"
  rendered="#{!MbInstitution.view}"
  >
 <f:selectItems value="#{MbInstitution.availableLanguages}"/>
</h:selectOneListbox>

It says: "duplicate Id for a component instForm:lang"
I know that i have 2 elements with same Id, but one is rendered only when another isn't. So, i didn't think it would be a problem. Actually it's not a big problem at all as i don't need this id, but what if i needed then what would i do?

分享到QQ

分享到微博

如果你对这篇内容有疑问，欢迎到本站社区发帖提问参与讨论，获取更多帮助，或者扫码二维码加入 Web 技术交流群。

发布评论

需要登录才能够评论，你可以免费注册一个本站的账号。

缪败 2024-08-12 00:25:16

您的问题是，这两个组件是该页面的 JSF 组件树的一部分。即使它们不能同时显示，它们也共享相同的 ID，这是 JSF 不允许的。

我看到三种解决方案可以解决您的问题：

第一个解决方案： 定义两个不同的 ID

第二个解决方案： 您可以按照 Wayne Young 的解释，使用 NamingContainer，它将为它们添加前缀ID 由 NamingContainer 的 ID 确定。

第三种解决方案：仅使用一个，然后在Java代码中进行区别。

<h:selectOneListbox id="lang" size="5" disabled="#{!MbInstitution.managingNew}" value="#{MbInstitution.node.lang}" valueChangeListener="#{MbInstitution.changeLanguage}">
    <a4j:support event="onchange" reRender="shortDesc, fullDesc" rendered="#{MbInstitution.view}"/>
    <f:selectItems value="#{MbInstitution.languages}"/>
</h:selectOneListbox>

Java代码：

public List<SelectItem> getLanguage() {
    if (isView()) {
        return getLanguagesByInstitute();
    } else {
        return getAvailableLanguages();
    }
}

public void changeLanguage(ValueChangeEvent evt) {
    if (!isView()) {
        return;
    }
    ...
}

Your problem is that these two components are part of the JSF Component tree for this page. And even if they cannot be displayed at the same time, they share the same ID, which is not allowed by JSF.

I see three solutions to solve your problem:

First solution: Define two differents ID

Second solution: You can, as explained by Wayne Young, use a NamingContainer, which will prefix their ID by the ID of the NamingContainer.

Third solution: Use only one <h:selectOneListbox/> and then make the difference in the Java code.

<h:selectOneListbox id="lang" size="5" disabled="#{!MbInstitution.managingNew}" value="#{MbInstitution.node.lang}" valueChangeListener="#{MbInstitution.changeLanguage}">
    <a4j:support event="onchange" reRender="shortDesc, fullDesc" rendered="#{MbInstitution.view}"/>
    <f:selectItems value="#{MbInstitution.languages}"/>
</h:selectOneListbox>

Java code:

public List<SelectItem> getLanguage() {
    if (isView()) {
        return getLanguagesByInstitute();
    } else {
        return getAvailableLanguages();
    }
}

public void changeLanguage(ValueChangeEvent evt) {
    if (!isView()) {
        return;
    }
    ...
}

回复收藏 0 原文