使用 &lt;ui:repeat&gt;&lt;h:inputText&gt;在列表<字符串>上不更新模型值 [英] Using &lt;ui:repeat&gt;&lt;h:inputText&gt; on a List&lt;String&gt; doesn&#39;t update model values

问题描述

这是场景(简化):

有一个 bean(称之为 mrBean)，它有一个成员和适当的 getter/setter:

There is a bean (call it mrBean) with a member and the appropriate getters/setters:

private List<String> rootContext;

public void addContextItem() {
    rootContext.add("");
}

JSF 代码:

<h:form id="a_form">
            <ui:repeat value="#{mrBean.stringList}" var="stringItem">
                    <h:inputText value="#{stringItem}" />
            </ui:repeat>
            <h:commandButton value="Add" action="#{mrBean.addContextItem}">
                <f:ajax render="@form" execute="@form"></f:ajax>
            </h:commandButton>
</h:form>

问题是，当单击添加"按钮时，在 <h:inputText/> 中输入的值代表了 stringList 没有被执行.

The problem is, when clicking the "Add" button, the values that were entered in the <h:inputText/> that represent the Strings in the stringList aren't executed.

实际上，mrBean.stringList setter (setStringList(List stringList)) 永远不会被调用.

Actually, the mrBean.stringList setter (setStringList(List<String> stringList)) is never called.

知道为什么吗?

一些信息-我在 Tomcat 6 上使用 MyFaces JSF 2.0.

Some info - I'm using MyFaces JSF 2.0 on Tomcat 6.

推荐答案

String 类是不可变的，并且没有值的 setter.getter 基本上是 Object#toString() 方法.

The String class is immutable and doesn't have a setter for the value. The getter is basically the Object#toString() method.

您需要直接在 List 上获取/设置值.您可以通过 提供的列表索引来实现.

You need to get/set the value directly on the List instead. You can do that by the list index which is available by <ui:repeat varStatus>.

<ui:repeat value="#{mrBean.stringList}" varStatus="loop">
    <h:inputText value="#{mrBean.stringList[loop.index]}" />
</ui:repeat>

您也不需要 stringList 的 setter.EL 将通过 List#get(index) 获取 item 并通过 List#add(index,item) 设置 item.

You don't need a setter for the stringList either. EL will get the item by List#get(index) and set the item by List#add(index,item).

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