Google's new recaptcha not validating - asp.net-mvc

Question

Am I missing something? I copied this code snippet over:
Automatically render the reCAPTCHA widget
I entered my registered data-sitekey. The reCAPTCHA displays and works when I check the box, but if I don't check the box and submit my form, the reCAPTCHA doesn't stop the user submission and my controller processes the request.
#model Medicaid.WebUI.ViewModels.RequestModel
<script src='https://www.google.com/recaptcha/api.js' async defer></script>
<table class="table">
<tr>
<td>
#using (Html.BeginForm("Index", "Home", FormMethod.Post, new { id = "request-form", #class = "form-horizontal" }))
{
#Html.AntiForgeryToken()
<fieldset>
<legend>Request</legend>
<div class="form-group">
<label for="inputFirstName" class="col-lg-2 control-label">First Name</label>
<div class="col-lg-10">
<input type="text" value="#Model.FirstName" class="form-control" maxlength="50" name="FirstName" id="FirstName" placeholder="First Name" required>
</div>
</div>
<div class="form-group">
<label for="inputLastName" class="col-lg-2 control-label">Last Name</label>
<div class="col-lg-10">
<input type="text" value="#Model.LastName" class="form-control" maxlength="50" name="LastName" id="LastName" placeholder="Last Name" required>
</div>
</div>
<div class="form-group">
<label for="inputEmail" class="col-lg-2 control-label">Email</label>
<div class="col-lg-10">
<input type="email" value="#Model.Email" class="form-control" maxlength="100" name="Email" id="Email" placeholder="Email" required>
</div>
</div>
<div class="form-group">
<div class="col-lg-10 col-lg-offset-2"><br /><br />
<div class="g-recaptcha" data-sitekey="IenterMykeyHere"></div><br /><br />
<button type="submit" class="btn btn-primary">Submit Request</button>
</div>
</div>
</fieldset>
}
</td>
</tr>
</table>
<br /><br />
#Html.ValidationSummary()

Answer 1

I was having this issue and re-read the documentation, and worked it out as the following:
function onBegin() {
$("input[type='hidden']").val(grecaptcha.getResponse());
}
You have to add a javascript function to the "onBegin" parameter of the AjaxOptions object from the MVC html helper - that will copy the value of the widget's response to a hidden variable you need to declare inside your form, so the submit button sends it to the controller. Don't forget to add a variable with the same name to the "RequestModel" view model so that the mvc model-binding passes it and you then will be able, in the server, to know if the user has clicked the button or not.
#using (Ajax.BeginForm("NewRecaptchaVerify", "ReCaptcha", new AjaxOptions
{
HttpMethod = "Post",
OnSuccess = "onSuccess",
OnFailure = "onFailure",
OnBegin = "onBegin",
OnComplete = "onComplete"
}))
{
#Html.HiddenFor(m => m.Response)
<div class="g-recaptcha" data-sitekey="your-site-key"></div>
<input type="submit" id="btnSubmit" value="Submit" />
}
(for the record, I am now facing the problem of knowing, in the server, in cases where the widget prompted the user to enter a text input, after clicking the button - whether he/she entered the text or not. Seems to me that in the end I will have no way out other than performing a GET request, in the server, to the widget's api, as they put it in the documentation: https://www.google.com/recaptcha/api/siteverify?secret=your_secret&response=response_string&remoteip=user_ip_address