MvcCaptchaLib

ASP.NET MVC compliant captcha generation library.

Features

The following features are supported:

• Fully customizable rendering engine
• AJAX-enabled captcha image refresh
• Integrates into ASP.NET MVC workflow by providing the special CaptchaResult action result and Captcha controller's extension method.
• Provides support of entered captcha code validation using declarative approach by ValidateCaptcha validation attribute

Using

###Generating captcha image

Write the following code to the controller's action method:

	public ActionResult GetCaptcha()
	{
		return this.Captcha();
	}

###Validating captcha code

Write following code to the model you use:

	[ValidateCaptcha]
	public string Captcha {get;set;}

The validation then runs as usual and you can check is the model valid by accessing ModelState.IsValid property in your action method.

###Rendering to the HTML

Write the following code to the view:

	@Html.CaptchaFor(m => m.Captcha, "GetCaptcha", "Is captcha unintelligible? Reload new one.")
	@Html.ValidationMessageFor(m => m.Captcha)

Copy captcha.js file to your web application project. (This script uses Jquery 1.3+, make sure you also reference this as well.) Add reference to the javascript like this:

	<script type="text/javascript" src="@Url.Content("~/Scripts/captcha.js")"></script>

###Customization

You can customize rendering by setting a number of properies of CaptchaImage instance. Also you can place a number of captches onto the single page by providing unique captcha identifiers to Captcha method and ValidateCaptcha attribute.