客户端列表的 MVC 自定义验证

我正在尝试编写一个在客户端工作的自定义验证器，用于验证所有复选框是否已被选中。

这是模型的声明：

[DeclarationsAccepted(ErrorMessage = "You must tick all declarations")]        
    public IList<DeclarationQuestion> DeclarationQuestions { get; set; }

这是属性：

public class DeclarationsAccepted : ValidationAttribute, IClientValidatable
{
    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {

        var questions = value as IList<DeclarationQuestion>;

        if (questions != null && questions.All(c => c.Answer))
        {
            return ValidationResult.Success;
        }
        return new ValidationResult("You must accepted all declarations to continue");
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var modelClientValidationRule = new ModelClientValidationRule
        {
            ValidationType = "declarationsaccepted",
            ErrorMessage = FormatErrorMessage(metadata.DisplayName)
        };            
        yield return modelClientValidationRule;
    }
}

到目前为止一切顺利，可以在服务器端运行。

对于客户，我将其连接如下：

jQuery.validator.addMethod('declarationsaccepted', function (value, element, params) {

        //Implement logic here to check all boxes are ticked
        console.log(value);

        return false;
    }, '');


    jQuery.validator.unobtrusive.adapters.add('declarationsaccepted', {}, function (options) {
        options.rules['declarationsaccepted'] = true;
        options.messages['declarationsaccepted'] = options.message;
    });

我显示这样的复选框：

@{ var questionIndex = 0; }
        @foreach (var question in Model.DeclarationQuestions)
        {

                @Html.CheckBoxFor(model => Model.DeclarationQuestions[questionIndex].Answer, new { id = "DeclarationQuestions" + questionIndex})

            questionIndex++;
        }

然后使用以下命令显示验证消息：

@Html.ValidationMessageFor(c => c.DeclarationQuestions)

当我提交表单时，消息才会显示，但只有在回发到服务器之后才会显示。有什么办法让它在客户端工作吗？

您无法获得客户端验证的原因是因为 html 帮助程序生成data-val-*与属性关联的控件的属性。jquery.validate.unobtrusive解析表单时读取这些属性并使用规则，在由生成的适当元素中显示错误消息ValidationMessageFor()与该控件关联（它通过匹配id元素的属性 - 错误消息在跨度中生成<span for="TheIdOfTheAssociatedControl" ...>).

您不（也不能）生成属性控件DeclarationQuestions（仅适用于每个项目的属性DeclarationQuestions所以没有什么可以匹配的。

您可以通过包含自己的错误消息占位符并拦截来处理此问题.submit event

html（将css添加到样式#conditions-error as display:none;)

<span id="delarations-error" class="field-validation-error">
  <span>You must accept all declarations to continue.</span>
</span>

Script

var declarationsError = $('#delarations-error');
$('form').submit(function() {
  var isValid = $('.yourCheckBoxClass').not(':checked') == 0;
  if(!isValid) {
    declarationsError.show(); // display error message
    return false; // prevent submit
  }
});

$('.yourCheckBoxClass').change(function() {
  if($(this).is(':checked')) {
    declarationsError.hide(); // hide error message
  }
});

旁注：用于生成复选框的循环应该是

for (int i = 0; i < Model.DeclarationQuestions.Count; i++)
{
  @Html.CheckBoxFor(m => m.DeclarationQuestions[i].Answer, new { id = "DeclarationQuestions" + i})
}