MVC: Access data attributes in controller - asp.net-mvc-4

Question

Might be a asked and answered...sorry but, I've been searching for a while.
RAZOR VIEW
#foreach (var item in Model.LanguageList)
{
<li>
<a href="#Url.Action("ChangeLanguage", "UserHeader")" data_languageID="#item.LanguageID" data_someval="hello" data_somevalb="world">
<div class="flag #item.LanguageFlag">
</div>
<div class="flag-title"> #item.LanguageName</div>
</a>
</li>
}
How do I access the data attributes in my controller?
CONTROLLER
public ActionResult ChangeLanguage()
{
var x = ControllerContext; //// ??? get the collection of [data-xx] from where?
return RedirectToAction("Buttons", "Designer");
}

Answer 1

data-* attributes are client side values and are not sent in the request.
In order to send those values, add them as route values
#foreach (var item in Model.LanguageList)
{
<li>
<a href="#Url.Action("ChangeLanguage", "UserHeader", new { languageID=item.LanguageID, someval="hello", somevalb="world" })">
<div class="flag #item.LanguageFlag"></div>
<div class="flag-title"> #item.LanguageName</div>
</a>
</li>
}
and include parameters in your GET method for the values
public ActionResult ChangeLanguage(int LanguageID, string someval, string somevalb)
Alternatively you could handle this using javascript/jquery (the ChangeLanguage() method also needs to be modified as shown above)
$('a').click(function() {
// get the url
var url = $(this).attr('href');
// get the data attributes
var languageID = $(this).data('languageID');
var someVal= $(this).data('someval');
var someValB= $(this).data('somevalb');
location.href = url + '?languageID=' + languageID + '&someVal =' + someVal + '&someValB=' + someValB;
return false; // cancel the default redirect
});