日期范围验证 [英] Date range validation

问题描述

我想比较两个日期(StartDate和EndDate)，并检查一个日期是否在另一个日期之前.最简单的解决方案是只在支持bean上执行此操作，然后短路"该方法.

I want to compare two dates (StartDate and EndDate) and check whether one is before the other. The simplest solution is to just do it on the backing bean and "short-circuit" the method.

但是，此验证不会与其他表单验证同时发生.例如，如果我有另一个需要验证的字段(日期除外)且输入无效，则我只会收到该特定字段的消息.仅当其他字段有效时，我才会基于后备bean获得日期验证.

However this validation does not happen concurrently with the other form validations. For example if I have another field that requires validation (besides the dates) and has invalid input, I will only get a message for that specific field. Only if the other fields are valid will I get the date validation based on the backing bean.

有人有解决办法吗?

推荐答案

但是此验证不会与其他表单验证同时发生.

后备bean动作方法确实不打算执行输入验证.

A backing bean action method is indeed not intented to perform input validation.

有人知道吗?

使用正确的工具完成工作；使用普通的 Validator .

Use the right tool for the job; use a normal Validator.

@FacesValidator("dataRangeValidator")
public class DateRangeValidator implements Validator {
    // ...
}

使用单个验证器验证多个输入值反过来确实是一个故事.基本上，您应该将其他组件或其值捕获/传递到validate()方法实现中.以其最简单的形式，您可以为此使用<f:attribute>.假设您正在使用<p:calendar>来选择日期，这是一个具体的启动示例:

Validating multiple input values with a single validator is in turn however indeed a story apart. Basically, you should be grabbing/passing the other component or its value along into the validate() method implementation. In its simplest form, you could use <f:attribute> for this. Assuming that you're using <p:calendar> to pick dates, here's a concrete kickoff example:

<p:calendar id="startDate" binding="#{startDateComponent}" value="#{bean.startDate}" pattern="MM/dd/yyyy" required="true" />
<p:calendar id="endDate" value="#{bean.endDate}" pattern="MM/dd/yyyy" required="true">
    <f:validator validatorId="dateRangeValidator" />
    <f:attribute name="startDateComponent" value="#{startDateComponent}" />
</p:calendar>

(请注意binding属性，它使组件在EL作用域中完全以给定的变量名称提供；还请注意，此示例为原样，并且绝对不应将其绑定到Bean属性！)

(note the binding attribute, it makes the component available in the EL scope on exactly the given variable name; also note that this example is as-is and that you should absolutely not bind it to a bean property!)

dateRangeValidator的外观如下:

@FacesValidator("dateRangeValidator")
public class DateRangeValidator implements Validator {

    @Override
    public void validate(FacesContext context, UIComponent component, Object value) throws ValidatorException {
        if (value == null) {
            return; // Let required="true" handle.
        }

        UIInput startDateComponent = (UIInput) component.getAttributes().get("startDateComponent");

        if (!startDateComponent.isValid()) {
            return; // Already invalidated. Don't care about it then.
        }

        Date startDate = (Date) startDateComponent.getValue();

        if (startDate == null) {
            return; // Let required="true" handle.
        }

        Date endDate = (Date) value;

        if (startDate.after(endDate)) {
            startDateComponent.setValid(false);
            throw new ValidatorException(new FacesMessage(
                FacesMessage.SEVERITY_ERROR, "Start date may not be after end date.", null));
        }
    }

}

---

如果您碰巧使用了 JSF实用程序OmniFaces ，那么您也可以只使用其

---

If you happen to use JSF utility library OmniFaces, then you could also just use its <o:validateOrder> component. The requirement can be achieved as follows without the need for a custom validator:

<p:calendar id="startDate" value="#{bean.startDate}" pattern="MM/dd/yyyy" required="true" />
<p:calendar id="endDate" value="#{bean.endDate}" pattern="MM/dd/yyyy" required="true" />
<o:validateOrder components="startDate endDate" />

另请参见:

• JSF不会是否支持跨域验证，是否有解决方法?

See also:

• JSF doesn't support cross-field validation, is there a workaround?

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