验证ViewParam和a4j:commandButton [英] Validation of ViewParam and a4j:commandButton
问题描述
我认为我遇到了@ViewScoped与a4j:commandButton的错误.
I think i came across a bug of @ViewScoped with a4j:commandButton.
我有一个非常复杂的表格，其中所有需要使用a4j的动作，除了那些需要上传数据的动作. 并且，根据命令的顺序，viewParam的验证也会中断.
I have a very complex form where all actions use a4j, except those that need to upload data. And depending on the order of the commands the validation of the viewParam breaks.
这是工作代码:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml"
xmlns:h="http://java.sun.com/jsf/html"
xmlns:f="http://java.sun.com/jsf/core"
xmlns:a4j="http://richfaces.org/a4j" >
<f:metadata>
<f:viewParam id="viewParam" name="viewParam" value="#{bean.viewParam}" required="true" />
</f:metadata>
<h:head>
<title>Test View Param</title>
</h:head>
<h:body>
<h:message for="viewParam" />
<hr/>
<h:form>
#{bean.viewParam}<br/>
<h:commandButton value="cmdButton" />
<a4j:commandButton value="a4jBtn" execute="@this" render="@form" />
</h:form>
</h:body>
</html>
只需单击a4jBtn，然后单击cmdButton即可查看问题.
您会看到该参数仍然存在！但是验证失败.
just click on the a4jBtn and then on the cmdButton to see the problem.
you will see that the parameter is still there! but that the validation fails.
<t:saveState>没有帮助，
<rich:message>也不是更好，但是
<t:saveState> does not help,
<rich:message> is also not better, but
<h:commandButton value="ajaxBtn" ><f:ajax execute="@this" render="@form" /></h:commandButton>
代替
<a4j:commandButton value="a4jBtn" execute="@this" render="@form" />
工作正常！
在Tomcat 6.0.18和jboss-el 2.0.0.GA上使用myFaces 2.0.15和richFaces 4.2.3.Final.
Using myFaces 2.0.15 and richFaces 4.2.3.Final on Tomcat 6.0.18 and jboss-el 2.0.0.GA.
我可以通过使用f:ajax而不是a4j:commandButton解决问题，但是也许您有更好的主意，或者您可以向我解释出了什么问题?
i could workaround my problem by using f:ajax instead of a4j:commandButton, but maybe you have a better idea, or you could just explain to me what is going wrong?
推荐答案
您基本上需要在同步回发中保留视图参数.在使用OmniFaces时，可以为此使用 <o:form> .
You basically need to retain the view parameters on synchronous postbacks. As you're using OmniFaces, you could use <o:form> for that.
<o:form includeViewParams="true">
或者因为您已经在使用视图作用域的bean，所以仅在非回发时触发验证.
Or as you're already using a view scoped bean, trigger the validation only on non-postbacks.
<f:viewParam ... required="#{not facesContext.postback}" />
或者，当您使用OmniFaces时，可以使用 <o:viewParam> 来代替验证/转换/更新回发.
Or, as you're using OmniFaces, you could use <o:viewParam> instead which skips the validation/conversion/update on postbacks.
<o:viewParam ... />
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