Server-Side CAPTCHA for Sitefinity Forms
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Sitefinity 6.2 release will add captcha for form controls out of the box!
Register CAPTCHA as Form Control
First, go to the Sitefinity backend in Administration >> Settings switch to Advanced Settings and browse Toolboxes >> FormControls >> Sections >> Common >> Tools (this will register a RadCaptcha control inside Common section)
Click Create new and set Control CLR Type or Virtual Path to Telerik.Web.UI.RadCaptcha, Telerik.Web.UI put a name (without spaces) and a title for the UI.
Adding Custom Form Library to Sitefinity project
Next step is to implement new form control to fire RadCaptcha validation.
In Visual Studio add a project library. Add all necessary .dll dependencies (Telerik.Sitefinity.dll, Telerik.Web.UI.dll) found in SitefinityWebApp\bin. Add this library as a reference in SitefinityWebApp in order to be accessible in Sitefinity.
Code:
using System;using System.ComponentModel;using System.Linq;using Telerik.Sitefinity.Modules.Forms.Web.UI;using Telerik.Sitefinity.Services;using Telerik.Sitefinity.Web.UI;using Telerik.Web.UI;namespace NewFormControl{ public class FormControlWithCaptcha:FormsControl { private readonly string captchaErrorMessage = "Invalid Code, please try again"; private RadCaptcha captcha; protected RadCaptcha MyCaptcha { get { if (!SystemManager.IsDesignMode) { //retrieve the captcha control from the list of controls in the form foreach (object control in base.FormControls.Controls[1].Controls) { if (control.GetType() != typeof(RadCaptcha)) { continue; } this.captcha = control as RadCaptcha; break; } } return this.captcha; } } protected override void InitializeControls(GenericContainer container) { if (!SystemManager.IsDesignMode) { base.InitializeControls(container); base.BeforeFormSave += new EventHandler<CancelEventArgs>(this.FormsControlCustom_BeforeFormSave); } } protected void FormsControlCustom_BeforeFormSave(object sender, CancelEventArgs e) { if (this.MyCaptcha != null && !this.MyCaptcha.IsValid) { e.Cancel = true; this.MyCaptcha.ErrorMessage = this.captchaErrorMessage; } } }}The code is quite simple – it inherits old FormsControl, adds an event to fire validation in base.InitializeControls(container) method. Adds a captcha error message, shown if the validation code doesn`t match.
The referenced project must be built under .NET 4.0 (if the target framework is 4.5 it will be incompatible with SitefinityWebApp)
Registering the Custom Form as a page control
Register this new form control as a page control.
Go to Administration >> Settings switch to Advanced Settings and browse Toolboxes >> PageControls >> Sections >> ContentToolboxSection >> Tools
Click Create new and set Control CLR Type or Virtual Path to NewFormControl.FormControlWithCaptcha put a name (without spaces) and a title for the UI.
As a result we got fully working form control with captcha:
Here you can download the complete sample.
