JSF 2.0:如何跳过JSR-303 bean验证? [英] JSF 2.0: How to skip JSR-303 bean validation?

问题描述

单击按钮时如何跳过使用JSF的JSR-303 Bean验证?

How to skip JSR-303 Bean validation with JSF, when a button is clicked?

一个冗长的问题来解释几种方法...考虑以下形式的列表:

A bit lengthy question to explain a few approaches... Consider a list in a form:

<h:form id="form">
    <h:commandButton value="Add row">
        <f:ajax execute="foo" listener="#{bean.add()}" render="foo" />
    </h:commandButton>
    <h:dataTable id="foo" var="foo" value="#{bean.foos}">
        <h:column>
            Name: <h:inputText id="field" value="#{foo.name}" required="true" />
            <h:messages for="field" />
        </h:column>
        <h:column>
            <h:commandButton value="Remove">
                <f:ajax execute=":form:foo" listener="#{bean.remove(foo)}" render=":form:foo" />
            </h:commandButton>
        </h:column>
    </h:dataTable>
</h:form>

当用户单击添加或删除行时，该操作应在未经验证的情况下执行.问题是，JSF重新呈现整个列表并尝试对其进行验证.如果存在未验证的草稿更改，则会发生验证错误，并且永远不会调用listener方法(因为验证失败会阻止这种情况).但是，即使验证错误，将immediate="true"添加到f:ajax仍允许方法执行.但是，仍然会发生验证错误，并在此处显示.

When user clicks add or remove row, the action should execute without validation. The problem is, JSF re-renders the whole list and tries to validate it. If there are draft changes that don't validate, validation errors occur and the listener method is never called (as failed validation prevents that). However, adding immediate="true" into f:ajax allows method to execute despite of validation errors. However, validation errors still occur and are shown here.

我看到两个选择:

1)使用Instant ="true"，并且不显示验证错误

1) Use immediate="true" and do not show validation errors

对于非验证按钮，请设置"instant ="true"，对于h:messages，请执行以下操作:

For non-validating buttons, set immediate="true" and for h:messages do:

<h:messages rendered="#{param['SHOW_VALIDATION']}" />

然后设置保存"按钮(实际上应该尝试保存表单)以发送该参数:

Then set Save-button (that should actually try to save the form) to send that parameter:

<h:commandButton>
    <f:param name="SHOW_VALIDATION" value="true" />
</h:commandButton>

这会导致进行验证，但是仅显示SHOW_VALIDATION参数时，才会显示消息.

This causes validation occur, but messages are simply not shown except when SHOW_VALIDATION parameter is present.

2)有条件地在facelets中声明验证:

2) Declare validation in facelets conditionally:

<h:inputText>
    <f:validateRequired disabled="#{!param['VALIDATE']}" />
</h:inputText>

和保存按钮:

<h:commandButton>
    <f:param name="VALIDATE" value="true" />
</h:commandButton>

这将导致仅当存在VALIDATE参数时(=按下保存按钮时)，字段才有效.

This causes fields to validate only when the VALIDATE parameter is present (=when the Save-button has been pressed).

但是这些似乎有点骇人听闻.我该如何简单地使用JSR-303 Bean验证，但在声明时跳过呢?

But these seem sort of a hacks. How can I simply use JSR-303 Bean Validation but skip it when declared?

推荐答案

将事件处理程序设置为immediate=true，并在退出它们之前调用FacesContext.renderResponse().

Set your event handlers as immediate=true and call FacesContext.renderResponse() before exiting them.

更新:

您的示例表单中的修改:

Modifications in your example form:

<h:form id="form">
    <h:commandButton value="Add row">
        <!-- Added immediate="true" to call bean.add() before validation phase -->
        <f:ajax execute="foo" listener="#{bean.add()}" render="foo" immediate="true"/>
    </h:commandButton>
    <h:dataTable id="foo" var="foo" value="#{bean.foos}">
        <h:column>
            Name: <h:inputText id="field" value="#{foo.name}" required="true" />
            <h:messages for="field" />
        </h:column>
        <h:column>
            <h:commandButton value="Remove">
                <!-- Added immediate="true" to call bean.remove() before validation phase -->
                <f:ajax execute=":form:foo" listener="#{bean.remove(foo)}" render=":form:foo" immediate="true"/>
            </h:commandButton>
        </h:column>
    </h:dataTable>
</h:form>

您的bean代码中的修改:

Modifications in your bean code:

...
public void add() {
    // Your add() code
    ...
    // Added FacesContext.renderResponse() call to skip to render response phase
    FacesContext.getCurrentInstance().renderResponse();
}
...
public void remove() {
    // Your remove() code
    ...
    // Added FacesContext.renderResponse() call to skip to render response phase
    FacesContext.getCurrentInstance().renderResponse();
}
...

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