使用ui:param传递值并在Backing bean中访问它们 [英] Passing values with ui:param and access them in Backing bean

问题描述

<ui:insert>
        <ui:include src="#{PopUpBean.includeUrl}">
           <ui:param name="includeParam" id="includeParam" value="HalloWert!"  />                                  
        </ui:include>
</ui:insert>

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这就是我尝试访问参数的方式，我已经在调试器的帮助下查找了每个变量，但似乎ui:param值未传递:

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Thats the way i tried to accses the parameters, i have lookedup every variable with help of the debugger, but it seems as if the ui:param value isn't passed:

    private void init () {
   FacesContext ctx =  FacesContext.getCurrentInstance();
   ExternalContext ectx = ctx.getExternalContext();
   Object o = ectx.getRequestParameterMap().get("includeParam");
   Object request =  ectx.getRequest();
}

@PostConstruct
public void postContruction () {
    this.init();
}

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谢谢您的帮助！

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Thank you for help!

推荐答案

找到了解决方案；

  HtmlOutputLabel ob = (HtmlOutputLabel) UiTreeWalker.findComponent(FacesContext.getCurrentInstance().getViewRoot(), "hiddenValue");
       ValueExpression vb = ob.getValueExpression("value");
      Object value =  vb.getValue(FacesContext.getCurrentInstance().getELContext());

隐藏值是带有render = false的outputLabel

Hidden Value is a outputLabel with rendered = false

其背后的想法是，您可以将参数放在JSF页面上的隐藏值中，然后可以从此Java代码段访问该参数.

The idea behind this is that you can put the parameter in a hidden value on your JSF page, and then you can access that parameter from this java snippet.

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