Client-side custom annotation validation not working

问题

I am trying to get client-side validation working with custom annotations in an ASP.NET MVC app. Sorry for the somewhat lengthy post.

Here is the custom attribute:

public class CustomStringLengthAttribute : ValidationAttribute, IClientValidatable
{
    public int MaxLength { get; private set; }
    public int MinLength { get; set; }

    public CustomStringLengthAttribute(int maxLength)
        : base(GetDefaultErrorMessage)
    {
        MaxLength = maxLength;
    }

    private static string GetDefaultErrorMessage()
    {
        return "Max length {1}";
    }

    public override string FormatErrorMessage(string name)
    {
        return string.Format(ErrorMessageString, name, MaxLength, MinLength);
    }

    protected override ValidationResult IsValid(object value, ValidationContext validationContext)
    {
        ...

        if (length > MaxLength || length < MinLength)
            return new ValidationResult(FormatErrorMessage(validationContext.DisplayName));

        return ValidationResult.Success;
    }

    public IEnumerable<ModelClientValidationRule> GetClientValidationRules(ModelMetadata metadata, ControllerContext context)
    {
        var rule = new ModelClientValidationRule();
        rule.ErrorMessage = FormatErrorMessage(metadata.GetDisplayName());
        rule.ValidationType = "customstringlength";
        rule.ValidationParameters.Add("max", MaxLength);
        rule.ValidationParameters.Add("min", MinLength);

        yield return rule;
    }
}

I use the attribute in my view model:

[CustomStringLength(25)]
public virtual string BillAddress1 { get; set; }

The data- attributes appear to be generated as they should:

<input data-val="true" data-val-customstringlength="Max length 25" data-val-customstringlength-max="25" data-val-customstringlength-min="0" id="BillAddress1" name="BillAddress1" type="text" value="">

The client-side validation kicks in, but I get "Uncaught TypeError: Cannot read property 'call' of undefined" in jquery.validate.js

This is from "check: function(element) ..." in jquery.validate.js - the method variable is "undefined":

Looking at the rules variable explains why the method variable is undefined - for some reason the array containing the min and max parameters is "undefined" instead of being named "customstringlength":

But why is it "undefined"??

Here is my customValidation.js, where I add the adapter, etc:

(function ($) {
    if ($.validator && $.validator.unobtrusive) {

        $.validator.unobtrusive.adapters.addMinMax("customstringlength", "min", "max");

        $.validator.addMethod("customstringlength", function (value, element, min, max) {
            if (value) {
                if (value.length < min || value.length > max) {
                    return false;
                }
            }
            return true;
        });
    }
}(jQuery));

Here is where I invoke the validation for the form:

function validateForm(form) {
    prepareValidationScripts(form);
    var validator = $.data(form[0], 'validator');
    return validator.form();
}

function prepareValidationScripts(form) {
    if (form.executed)
        return;
    form.removeData("validator");
    $.validator.unobtrusive.parse(document);
    form.executed = true;
}

I have been staring at this for too long - what am I missing??

回答1:

I finally got this working! I decided not to try to use the "convenience" addMinMax adapter, but instead write a custom adapter. Here is the updated customValidation.js (everything else stays the same):

(function ($) {
    if ($.validator && $.validator.unobtrusive) {

        $.validator.unobtrusive.adapters.add('customstringlength', ['min', 'max'], function(options) {
            options.rules['customstringlength'] = {
                min: options.params.min,
                max: options.params.max,
            };
            options.messages['customstringlength'] = options.message;
        });

        $.validator.addMethod('customstringlength', function (value, element, params) {
            if (value) {
                if (value.length < params.min || value.length > params.max) {
                    return false;
                }
            }
            return true;
        });
    }
}(jQuery));

来源：https://stackoverflow.com/questions/24298112/client-side-custom-annotation-validation-not-working