JSF2.0-具有可选方法表达式的复合组件 [英] JSF2.0 - Composite component with optional method expression

问题描述

我正在实现一个复合组件，但是发现了一个找不到解决方案的问题.

I'm implementing a composite component and I found a issue which I didn't find a solution.

我指定了页面作者无法传递的属性，但是我无法指定方法属性(Action的方法表达式)，如果该属性未传递，则复合组件不会使用Composite:implementation标记中的method属性.

I specified its attributes that can or not be passed by the page author, but I couldn't specify a method attribute (a method expression to Action) that, if it wasn't passed, the composite component doesn't use the method attribute in the composite:implementation tag.

这是我的代码:

<composite:interface>
    <composite:attribute name="namePrompt" required="true"/>
    <composite:attribute name="actionMethod" method-signature="java.lang.String  action()" required="false"/>
    <composite:attribute name="showComponent" default="false"/>
</composite:interface>

<composite:implementation>
    <div>
       <p:commandLink actionListener="#{cc.attrs.actionMethod}"
                      rendered="#{cc.attrs.showComponent}"
                      >
            <h:outputText value="#{cc.attrs.namePrompt}"/>    
       </p:commandLink>
    </div>
</composite:implementation>

使用它时，我没有指定"actionMethod"属性.像这样:

When using it, I didn't specify the "actionMethod" attribute. Like this:

<util:foo namePrompt="SomeName" showComponent="true"/>

但是我收到错误消息:

javax.faces.FacesException: Unable to resolve composite component from using page using EL expression '#{cc.attrs.actionMethod}'

有没有办法做到这一点?

Is there a way to do this?

推荐答案

您将必须创建两个p:commandLink元素，并根据参数的定义有条件地呈现它们:

You will have to create two p:commandLink elements and render them conditionally according to definition of your parameter:

<p:commandLink actionListener="#{cc.attrs.actionMethod}" rendered="#{!empty cc.getValueExpression('actionMethod') and cc.attrs.showComponent}">
  <h:outputText value="#{cc.attrs.namePrompt}"/>
</p:commandLink>
<p:commandLink rendered="#{empty cc.getValueExpression('actionMethod')}">
  <h:outputText value="#{cc.attrs.namePrompt}"/>
</p:commandLink>

这篇关于JSF2.0-具有可选方法表达式的复合组件的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！