Generating an action URL in JavaScript for ASP.NET MVC

Question

I'm trying to redirect to another page by calling an action in controller with a specific parameter. I'm trying to use this line:

window.open('<%= Url.Action("Report", "Survey",
    new { id = ' + selectedRow + ' } ) %>');

But I couldn't make it work; it gives the following error:

CS1012: Too many characters in character literal.

Can't I generate the action URL this was on the client side? Or do I have to make an Ajax call by supplying the parameter and get back the needed URL? This doesn't seem right, but I want to if it's the only way.

Is there an easier solution?

Answer 1

Remember that everything between <% and %> is interpreted as C# code, so what you're actually doing is trying to evaluate the following line of C#:

Url.Action("Report", "Survey", new { id = ' + selectedRow + ' } )

C# thinks the single-quotes are surrounding a character literal, hence the error message you're getting (character literals can only contain a single character in C#)

Perhaps you could generate the URL once in your page script - somewhere in your page HEAD, do this:

var actionUrl =
    '<%= Url.Action("Report", "Survey", new { id = "PLACEHOLDER" } ) %>';

That'll give you a Javascript string containing the URL you need, but with PLACEHOLDER instead of the number. Then set up your click handlers as:

window.open(actionUrl.replace('PLACEHOLDER', selectedRow));

i.e. when the handler runs, you find the PLACEHOLDER value in your pre-calculated URL, and replace it with the selected row.

Answer 2

I usually declare a javascript variable in the section to hold the root of my website.

<%="<script type=\"text/javascript\">var rootPath = '"
    + Url.Content("~/") + "';</script>" %>

To solve your problem I would simply do

window.open(rootPath + "report/survey/" + selectedRow);