/// <summary>
/// Generates CAPTCHA HTML using reCAPTCHA.
/// </summary>
/// <param name="htmlHelper">The view's HTML helper.</param>
/// <param name="fallbackMessage">An optional message to display above the CAPTCHA when it is displayed as a fallback.</param>
/// <returns>The reCAPTCHA HTML.</returns>
public IHtmlString Generate(
HtmlHelper htmlHelper,
string fallbackMessage = null)
{
if (htmlHelper == null)
{
throw new ArgumentNullException("htmlHelper");
}
IConfigurationSource configurationSource = GetConfigurationSource();
var publicApiKey = configurationSource.GetConfigurationValue(Const.ReCaptchaPublicKeyAppSettingKey);
if (publicApiKey == null)
{
if (!htmlHelper.ViewContext.HttpContext.Request.IsLocal)
{
throw new InvalidOperationException(ErrorMessage.DefaultReCaptchApiKeysOnlyAllowedForLocalRequest);
}
publicApiKey = Const.ReCaptchaLocalhostPublicKey;
}
var privateApiKey = configurationSource.GetConfigurationValue(Const.ReCaptchaPrivateKeyAppSettingKey);
if (privateApiKey == null)
{
if (!htmlHelper.ViewContext.HttpContext.Request.IsLocal)
{
throw new InvalidOperationException(ErrorMessage.DefaultReCaptchApiKeysOnlyAllowedForLocalRequest);
}
privateApiKey = Const.ReCaptchaLocalhostPrivateKey;
}
var recaptchaControl = new RecaptchaControl
{
ID = Const.ReCaptchControlId,
PublicKey = publicApiKey,
PrivateKey = privateApiKey,
};
var htmlWriter = new HtmlTextWriter(new StringWriter());
recaptchaControl.RenderControl(htmlWriter);
var captchaHtml = htmlWriter.InnerWriter.ToString();
const string template = @"<div class=""PoliteCaptcha editor-field""><span class=""field-validation-error"" data-valmsg-for=""PoliteCaptcha""><span htmlfor=""PoliteCaptcha"">{0}</span></span>{1}</div>";
return(new MvcHtmlString(string.Format(template, fallbackMessage ?? Const.DefaulFallbackMessage, captchaHtml)));
}