如何为最小选择设置素数selectCheckboxMenu验证器 [英] How to set primefaces selectCheckboxMenu validator for minimum selects

问题描述

我想为primefaces selectCheckboxMenu写一个验证器，以防止用户选择少于5个值.

I want to write a validator for primefaces selectCheckboxMenu to prevent user from selecting less than 5 values.

我尝试实现BalusC RequiredCheckboxValidator 但不知道如何访问所选值的大小，有人可以让我走上正确的路吗?

I've tried to implement BalusC RequiredCheckboxValidator but couldn't know how to access the size of selected values, can someone put me on the right path?

推荐答案

您将以这种方式进行.

xhtml

xhtml

<p:selectCheckboxMenu value="#{mainBean.selectedList}" >  
    <f:selectItems value="#{mainBean.map}" />  
    <f:validator validatorId="limitCheckboxMenuValidator" />                       
    <f:attribute name="minLimit" value="5" />
</p:selectCheckboxMenu>  

验证器

Validator

@FacesValidator("limitCheckboxMenuValidator")
public class LimitCheckboxMenuValidator implements Validator {

   public LimitCheckboxMenuValidator() {

   }

   @Override
   public void validate(FacesContext context, UIComponent component,
           Object value) throws ValidatorException { 
       //get limit
       Integer minLimit =    Integer.parseInt((String)component.getAttributes().get("minLimit"));
       SelectCheckboxMenu myComponent = (SelectCheckboxMenu)component;

       if (((String[])myComponent.getSubmittedValue()).length < minLimit) {
           FacesMessage msg
                   = new FacesMessage("Limit failed",
                           "Min selection must be " + minLimit);
           msg.setSeverity(FacesMessage.SEVERITY_ERROR);
           throw new ValidatorException(msg);
       } 
   }
}

可以在github [在线演示.

A small working example can be found on github [1] [2], and an online Demo.

希望这会有所帮助.

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