Passing a model to a different controller from a view - asp.net

Question

I have this button:
<button type="button" onclick="location.href='#Url.Action("Index", "Registration">Register</button>
Its on a sign-in page that has this link which goes to a registration page. I'd like to preserve the username and password entered on this page when the user clicks the link to go to the registration page, so is there a way to pass it a new model such that the user goes to the registration page and already has their ID and password entered?
For example, I am trying to do something like this:
<button type="button" onclick="location.href='#Url.Action("Index", "Registration", new RegistrationModel { ID = Model.ID, Password = Model.Password })'">Register</button>

Answer 1

All you need to do is just post your values to which ever controller you want to handle it and share the same textbox names.
Say you have a view like so, containing your form:
#model LoginFormViewModel
#* Form element defaults to posting to Login controller, but has an attribute containing the URL to the Registration controller should we need it *#
<form id="login_form" method="post" action="#Url.Action("Index", "Login")" data-registration-url="#Url.Action("Index", "Registration")">
#* Username field *#
#Html.TextBoxFor(x => x.Username)
#* Password field *#
#Html.PasswordFor(x => x.Password, new { value = Model.Password })
#* Hidden value that we can check in the controller *#
<input type="hidden" name="FromLoginPage" value="true" />
<input type="submit" value="Register" id="register_submit" />
<input type="submit" value="Login" />
</form>
I would use jQuery to control the submitting of the forms:
// User clicked regstration button, not login button
$(document).delegate('input#register_submit', 'click', function(e) {
// Prevent default submitting of the form to the login controller
e.preventDefault();
// Get registration URL from the attribute
var registerActionUrl = $('form#login_form').attr('data-registration-url');
// Submit the form to the registration controller
$('form#login_form').attr('action', registerActionUrl).submit();
});
Here's the model LoginViewModel and RegistrationViewModel that share properties with the same names (Username and Password), this will come in handy for binding up depending on which controller we submit the form to:
// Login model
public LoginViewModel
{
public string Username { get; set; }
public string Password { get; set; }
}
// Registration view model
public RegistrationViewModel
{
public string Username { get; set; }
public string Password { get; set; }
public bool FromLoginPage { get; set; }
// ... other fields that won't get bound when submitted from login page
public string ConfirmPassword { get; set; }
}
In the Login controller we handle things normally, but within the registration form we can do a quick check on FromLoginPage submitted from the login page to return the registration page back to the user with the fields populated:
// Login controller
[HttpPost]
public LoginController : Controller
{
public Index(LoginViewModel requestmodel)
{
// Validate login
// Process login
// Return the view
return View(requestmodel);
}
}
// Registration controller
[HttpPost]
public RegistrationController : Controller
{
public Index(RegistrationViewModel requestModel)
{
// Submitted from the login page?
if (requestModel.FromLoginPage)
{
// Clear any model validation errors so far
this.ModelState.Clear();
// Just load the registration page with the values populated
return View(requestmodel);
}
// A normal registration request from registration page, perform validation on entire model
// Process login here
return View(requestmodel);
}
}