将valueChangeListener方法表达式传递到标记文件中 [英] Passing valueChangeListener method expression into tag file

问题描述

我有一个<h:inputText>，带有如下所示的事件侦听器:

I have a <h:inputText> with an event listener like following:

<h:inputText valueChangeListener="#{myBean.handle}"/>

我想将其放在一个标签文件中，该文件将按以下方式使用:

I would like to put it in a tag file which is to be used as follows:

<my:itext changeListener="#{myBean.handle}" />

在标记文件中:

<h:inputText valueChangeListener="#{changeListener}" />

但是，它将它作为属性而不是作为侦听器方法进行评估.如何将侦听器方法传递到标记文件中?

However it's evaluating it as a property instead of as a listener method. How can I pass the listener method into a tag file?

推荐答案

您可以设计为不将方法表达式作为标记文件属性传递.基本上，您需要在标记文件中将ValueExpression转换为MethodExpression.

You can by design not pass method expressions as a tag file attribute. You basically need to convert the ValueExpression to a MethodExpression inside the tag file.

对于JSF 2.x Facelets，可以使用 OmniFaces <o:methodParam> 解决.

For JSF 2.x Facelets, this can be solved using OmniFaces <o:methodParam>.

<o:methodParam name="changeListenerMethod" value="#{changeListener}" />
<h:inputText valueChangeListener="#{changeListenerMethod}" />

但是，对于旧的和不建议使用的Facelets 1.x或JSP 2.x，没有现有的解决方案. OmniFaces <o:methodParam>是开源的，如果有必要，您应该能够为Facelets 1.x或JSP复制和更改它.

However, for old and deprecated Facelets 1.x or JSP 2.x there is no existing solution. The OmniFaces <o:methodParam> is however open source, you should be able to copy and alter it for Facelets 1.x or JSP if necessary.

请注意，当您实际上已经在使用JSF 2.x时，也可以使用复合组件反而.这支持将方法表达式作为<cc:attribute method-signature>传递.对于JSF 1.x，您也可以创建一个 real 定制组件，但这不仅仅只是一些XML.

Note that when you're actually already using JSF 2.x, you could also use a composite component instead. This supports passing method expressions as <cc:attribute method-signature>. For JSF 1.x you can alternatively also create a real custom component, but that's a bit more work than just some XML.

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