get request url after AJAX request - asp.net-mvc-4

Question

I have a search page with link Search?params but any subsequent search requests are made via Ajax forms using Asp.Net. It makes a request to an action with a different name like InstantSearch?params but in the browser I see Search?params.
From this page I have a link to another page and I need to save the Url to return back to this page.
But if I had an AJAX request, Request.Url returns InstantSearch?params, not the link from browser address bar. And the action from this link returns only a Partial View, so when it returns to the previous URL the page is messed up.
How do I get the link of the previous page, from the browser address bar in Asp.Net, not the actual last requested URL?
While searching we are loading masonry containers like this:
$("#main-content-container").load("/Kit/InstantSearch?" + parameters, function() {
$('#mason-container').imagesLoaded(function() {
$('#mason-container').masonry({
itemSelector: '.kit-thumb-container',
columnWidth: 210,
isFitWidth: true,
gutter: 10
});
});
});
Then I'm calling foundation Joyride on same page and need to pass current page URL to return back. Joyride calls onload of the page under this link:
#Html.ActionLink("Go to kit details help", "OrderPageHelp", "Kit", new { returnUrl = Request.Url }, new { #style = "font-size:16px;" })
The needed page return Url is Kit/Search?params, but Request.Url returns that last request when loading masonry with Kit/InstantSearch?params.
How can I pass the needed Url without hard-coding it?

Answer 1

So this ones a bit old but I found myself in a similar situation recently and found a quick work around. Posting it in case any one's interested.
You can solve this problem by taking advantage of the TempData class.
Temp Data can be used to store data in between requests. The information will remain as long as the session is active, until you retrieve the data again.
So when the user first loads the page, before the ajax method is triggered, store the data in a variable on the page AND in the TempData("YourVariableName") object. Create the Action Link with the Saved URL. When the ajax request is fired it will overwrite the value in Request.URL. So, Check for a value in the TempData("YourVariableName"), if it is there, use that value AND Reset the TempData("YourVariableName") value. This will keep the original value of the page URL even after many ajax requests have been triggered. Code in Visual Basic:
#Code
Dim LastURL As String = ""
If Not TempData("LastURL") Is Nothing Then
LastURL = TempData("LastURL")
TempData("LastURL") = LastURL
Else
LastURL = Request.Url.AbsoluteUri
TempData("LastURL") = LastURL
End If
End Code
And pass the value stored in the LastURL variable as a parameter to your action link.