如何调用有条件呈现的UICommand组件的操作方法? [英] How to call an action method of a UICommand Component which was rendered conditionally?
问题描述
操作方法未调用请参考此问题- ，我的UICommand组件之一是有条件地渲染的，在链接的问题5的回答中说-如果该组件或其任何父代的渲染或禁用属性为假，那么不会调用action方法吗?如果是这样，我如何实现相同的功能?有没有解决的办法?还是一个把戏?或其他任何方法?
action method is not called Please refer to this question - , One of my UICommand Component is rendered conditionally , it was said in the answer of the linked question - point 5 - that if the Component's or any of its parents rendered or disabled attributes are false - then the action method will not be called ? If thats the case- How do i achieve the same functionality? Is there a work around ? or a trick ? or any other approach ?
谢谢！
推荐答案
至此，您希望在后续请求中保留负责rendered条件的属性.有几种解决此问题的方法:
To the point, you'd like to retain the property responsible for the rendered condition in the subsequent request. There are several solutions for this problem:
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将bean放入会话范围.这很容易，但是很痛.这对用户体验不利，因为更改将反映在用户在同一会话中打开的所有选项卡/窗口中.
Put bean in session scope. It's easy, but it hurts. It's bad for user experience since changes will be reflected in all tabs/windows the user has open in the same session.
使用<h:inputHidden>传输属性.从理论上讲很容易，但是在实践中它也会带来伤害.每当以相同形式出现的任何其他输入中发生验证/转换错误时，该值即会丢失.这是JSF处理隐藏输入元素的方式的一个奇怪之处.一种解决方法是使用<h:inputHidden binding="#{bean.hidden}">并在bean中执行hidden.getValue()和hidden.setValue().
Use <h:inputHidden> to transfer the property. In theory easy, but in practice it hurts as well. The value will namely get lost whenever a validation/conversion error has occurred in any of other inputs in the same form. This is an odditity in how JSF handles hidden input elements. A workaround is to use <h:inputHidden binding="#{bean.hidden}"> and do a hidden.getValue() and hidden.setValue() in bean.
如果使用的是<h:commandLink>而不是<h:commandButton>，则可以使用<f:param>来传输属性.它可以作为request参数使用，您可以在bean的(post)构造函数中进行检查.
If you're using <h:commandLink> instead of <h:commandButton>, then you can use <f:param> to transfer the property. It will be available as request parameter, you can check for it in bean's (post)constructor.
使用 Tomahawk的
Use Tomahawk's <t:saveState>. The perfect solution as far. This will retain the value (or even a complete bean) in the subsequent request.
如果您已经在使用JSF 2.0，则 @ViewScoped 可以解决所有问题.它的行为类似于<t:saveState>.
If you're already on JSF 2.0, the @ViewScoped would have solved this all. It behaves like the <t:saveState>.
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