Using Inline C# inside Javascript File in MVC Framework

Question

I am trying to get inline c# to work in my javascript files using the MVC Framework. I made this little test code up.

  $(document).ready(function() {
      alert(<%= ViewData["Message"] %>);
  });

When this code is used inside of the view it works perfectly. When I get outside of my aspx view and try this in a javascript file I get illegal XML character. I figure this is by design in the MVC Framework but I haven't been able to find any material on this on the web. Has anyone gotten inline C# to work in javascript files using the MVC Framework?

Answer 1

That inline C# has to be processed by the server in order to make sense. Naturally, it won't work with a just-plain-JavaScript file.

Answer 2

when you have C# code in a separate file and include it in your View the Server does not process the code, the script file will be called by the browser and the inline script would be treated as plain string

alternatively you can try script runat=server when including you script file but I am not sure about the effects of this

Answer 3

.aspx files are the view files of MVC framework. The framework only renders the views and partial views. I do not think there would exist a way to use server-side code inside javascript files.

You can include your message in a hidden field

<%-- This goes into a view in an .aspx --%>
<%= Html.Hidden("MyMessage", ViewData["Message"]) %>

and use that inside your javascript file:

// This is the js file
$(document).ready(function() {
    alert($("#MyMessage").attr("value"));
});

Answer 4

As others have said, the C# is not being processed by the server.

A possible solution would be to have a separate view that uses the same model and outputs the JavaScript, then reference that view in your <script type="text/javascript" src="yourJSview.aspx"></script>.

Added as per SLaks' answer:

Set the content-type to text/javascript, and put your JavaScript source directly below the <%@ Page directive (without a <script> tag).

Beware that you won't get any IntelliSense for it in VS.

Answer 5

Your web server does not process .js files, it only serves them to the client. This is in contrast to .aspx or other ASP.NET file types. These files are interpreted by your server before they are served up to the client.

Answer 6

You could make an ASPX view that renders JavaScript.

Set the content-type to text/javascript, and put your JavaScript source directly below the <%@ Page directive (without a <script> tag).

Beware that you won't get any IntelliSense for it in VS.

Answer 7

I agree with Serhat. It's best to render an HTML Hidden field, or, as Al mentioned, go to a URL for it. This can be done through a Web Service or even an IHttpHandler implementation. Then you could use a url such as "messages.axd?id=17".

Answer 8

To add to Grant Wagner's answer and SLaks's answer, you can actually fool Visual Studio into giving you IntelliSense in his solution like so:

<%if (false) {%><script type="text/javascript"><%} %>
// your javascript here
<%if (false) {%></script><%} %>

In his solution it is required that when it renders to the page that there be no <script> tags, but that has a side effect that turns off JavaScript IntelliSense in Visual Studio. With the above, Visual Studio will give you IntelliSense, and at the same time not render the <script> tags when executed.