Add a global querystring paramter to T4MVC generated links

Question

How can I add a hook to T4MVC so that when I get a link to an action using T4MVC it checks if the current request has a parameter, lets say PIN=1234. If it exists, i want this parameter to be added to the generated link.

Answer 1

I created an extension method for UrlHelper that wraps the T4MVC's extension method for UrlHelper. This adds the required additional parameters to every link generated from T4MVC.

public static class T4MVCHelpers
{
    /// <summary>
    /// Returns a T4MVC generated url, passing along PIN
    /// </summary>
    public static string ActionUrl(this UrlHelper urlHelper, ActionResult result)
    {
        var pin = urlHelper.RequestContext.HttpContext.Request["Pin"];
        if (!string.IsNullOrEmpty(pin))
        {
            result.AddRouteValue("Pin", pin);
        }
        return urlHelper.Action(result);
    }
}

I then always call this wrapper method instead of T4MVC's method

var Url.ActionUrl(MVC.SomeController.Index(1));

Now depending on the requesting url. If the requesting url has no pin parameter it will look like this

/SomeController/Index?param1=1

Now depending on the requesting url. If the requesting url has PIN=123 it will look like this

/SomeController/Index?param1=1&PIN=123