MVC validation 02-Custom validation rules, message validation

Original: MVC validation 02-Custom validation rules, message validation

This article experiences the MVC custom validation feature to enable validation of messages. For custom validation attributes that have just been written, back-end validation is only supported at first. If you want to have front-end jquery support, you must also extend the validation of jquery.

This article is related to "MVC authentication 01-BASIC, Remote Authentication" and, if necessary, please refer to.

When we verify the properties of the email, we may write:

[RegularExpression (@ "\w.+\@\w.+")]

 Public string Email {get; set;}

This only takes into account the @ symbol, but that's not enough, and we might write:

[RegularExpression (@ "^[\w-]+ (\.[ \w-]+) *@ ([\w-]+\.) +[a-za-z]+$ ")]

 Public string Email {get; set;}

This is slightly "bloated", in fact, we can extend the ValidateAttribute feature of MVC to "one package, multiple use".

Custom validation Attributes

ExpandusingSystem.ComponentModel.DataAnnotations;usingSystem.Text.RegularExpressions;namespacemvcvalidation.extension{ Public Sealed classEmailattribute:validationattribute { Public Const stringReg = @ "^[\w-]+ (\.[ \w-]+) *@ ([\w-]+\.) +[a-za-z]+$"; PublicEmailattribute () {}//overriding base class methods         Public Override BOOLIsValid (Object value)        {if(value==NULL)return true;if(value  is string) {Regex regex =NewRegex (REG);returnRegex.IsMatch (value.            ToString ()); }return false; }    }}

Attention:
Declare your custom extension class as sealed class.
The regular expression that validates the message here is not necessarily the perfect one.

Where custom features are useful: View model

ExpandusingMvcvalidation.extension; Public classRegistermodel {[Required] [Stringlength (6, minimumlength = 2)]//Plus[Display (Name = "User name")] [Remote ("Checkusername","Validate", errormessage ="Remote authentication of user name failed")] Public stringUserName {Get;Set; } [Required] [DataType (datatype.emailaddress)] [Display (Name = "Mail")] [Email] Public stringEmail {Get;Set; } [Required] [stringlength (errormessage = "{ 0} field minimum {2} characters, up to {1} characters", Minimumlength = 6)] [DataType (Datatype.password)] [Display (Name ="Password")] Public stringPassword {Get;Set; } [DataType (Datatype.password)] [Display (Name = "Confirm Password")] [System.ComponentModel.DataAnnotations.Compare ("Password", errormessage ="The password and confirmation password do not match. ")] Public stringConfirmPassword {Get;Set; }    }

Register.cshtml

Expand@model mvcvalidation.models.registermodel@{viewbag.title = "Register";} class="title> using(Html.BeginForm ())        {@Html. AntiForgeryToken () @Html. ValidationSummary () <fieldset> <legend> Registration Form </legend> <ol> <li> @Html. labelfor (M = m.username) @Html. Textboxfor (M                + m.username) </li> <li> @Html. labelfor (M = m.email) @Html. textboxfor (M = m.email) </li> <li> @Html. labelfor (M = M.                Password) @Html. passwordfor (M = m.password) </li> <li> @Html. labelfor (M = M.confirmpassword) @Html. passwordfor (M = m.confirmpassword) </li&        Gt </ol> <input type= "Submit"value="Register"/> </fieldset>} @section Scripts {@Scripts. Render ("~/bundles/jqueryval")}

Effect:

Attention:
The custom validation feature at this time only supports back-end validation, and if you want to support front-end jquery validation, you need to implement the Iclientvalidatable interface.

Custom attributes implement the Iclientvalidatable interface to prepare for jquery validation

ExpandusingSystem.ComponentModel.DataAnnotations;usingSystem.Text.RegularExpressions;usingSYSTEM.WEB.MVC;namespacemvcvalidation.extension{ Public Sealed classEmailattribute:validationattribute, iclientvalidatable { Public Const stringReg = @ "^[\w-]+ (\.[ \w-]+) *@ ([\w-]+\.) +[a-za-z]+$"; PublicEmailattribute () {}//overriding base class methods         Public Override BOOLIsValid (Object value)        {if(value==NULL)return true;if(value  is string) {Regex regex =NewRegex (REG);returnRegex.IsMatch (value.            ToString ()); }return false; } PublicSystem.collections.generic.ienumerable<modelclientvalidationrule> Getclientvalidationrules (ModelMetadata metadata, ControllerContext context) {Modelclientvalidationrule rule =Newmodelclientvalidationrule {ValidationType = "Email", errormessage = formaterrormessage (metadata.            GetDisplayName ())}; YieldreturnRule }    }}

Attention:
The value of the ValidationType attribute must be lowercase, otherwise error.

Extend jquery to support custom extension features Emailattribute

JQuery.validator.email.js file:

Extension methods
$.validator.addmethod ("Email", function (value, Element) {
if (value = = False) {
return true;
}
This.optional (Element) | | /^[\w-]+ (\.[ \w-]+) *@ ([\w-]+\.) +[a-za-z]+$/i.test (value);
});

Extension method Registration
$.validator.unobtrusive.adapters.addbool ("email");

In order to implement jquery client authentication, the JS files required in the register.cshtml include:

1. Quoting Query-{version}.js
2. Quoting Jquery.validate.js
3. Quoting Jquery.validate.unobtrusive.js
4. Custom jquery Validation Extension

Because there is @scripts.render ("~/bundles/jquery") in _layout.cshtml, no references are required in all register.cshtml.
Register.cshtml contains @scripts.render ("~/bundles/jqueryval"), which means that references to 2 and 3 are included.
Register.cshtml also requires the introduction of jquery extension methods for custom attribute Emailattribute features.

The complete register.cshtml is as follows:

Expand@model mvcvalidation.models.registermodel@{viewbag.title = "Register";} class="title> using(Html.BeginForm ())        {@Html. AntiForgeryToken () @Html. ValidationSummary () <fieldset> <legend> Registration Form </legend> <ol> <li> @Html. labelfor (M = m.username) @Html. Textboxfor (M                + m.username) </li> <li> @Html. labelfor (M = m.email) @Html. textboxfor (M = m.email) </li> <li> @Html. labelfor (M = M.                Password) @Html. passwordfor (M = m.password) </li> <li> @Html. labelfor (M = M.confirmpassword) @Html. passwordfor (M = m.confirmpassword) </li&        Gt </ol> <input type= "Submit"value="Register"/> </fieldset>} @section Scripts {@Scripts. Render ("~/bundles/jqueryval") <script src="~/scripts/jquery.validator.email.js"&GT;&LT;/SCRIPT&GT;}

Effect:

How do I confirm that the jquery validation mechanism is enabled?
Before implementing Iclientvalidatable, review the form elements for email as follows:

After implementing Iclientvalidatable, review the form elements for email as follows:

Visible, after implementing Iclientvalidatable, the Data-val-email attribute is more.

Attention:
jquery itself contains validation of email, and the validation of jquery is extended for demonstration purposes.