Razor/JavaScript and trailing semicolon

问题:

Using Visual Studio 2012, on a Razor view page, in the JavaScript section, I am getting what I think is a battle between Razor syntax vs JavaScript syntax. In particular, the trailing semicolon in the script section is flagged by intellisense and a compiler warning (not error) is delivered:

'Warning 13 Syntax error'.

If I remove it, then I get a statement termination recommendation (ReSharper in this case, but just good practice).

<script type="text/javascript">
    $().ready(function(){
        var customer = @Html.Raw(ViewBag.CustomerJSON);  // <- Razor (I think) doesn't like this semicolon
    });
</script>

Is this a bug in Razor? If so, is there a way I can rewrite this to avoid this issue?

回答1:

Is this a bug in Razor?

Absolutely not. Run your application, and it will work as expected.

It is a bug in the tools you are using (Visual Studio 2012, ReSharper, ...) that are incapable of recognizing perfectly valid syntax and warning you about something that you shouldn't be warned about. You could try opening an issue on the Microsoft Connect site and signalling this bug if that hasn't already been done.

回答2:

Since this still seems to be happening and it is a nuisance I figured I will at least let others know what I ended up using as a "hack". I don't want to ignore the warning and would rather accept a hokier syntax (and yes someone is going to say this will kill performance :))

What I use as a workaround is to use a client side addition at the end. For me this error occurred on defining an "integer" constant, so

window.foo = @(Model.Something);

gave me the good old semicolon error. I simply changed this to:

window.foo = @Model.Something + 0;

(In the stated questions case you should just be able to add '', so + ''.

I know there is a whole another addition happening on the client and it isn't elegant, but it does avoid the error. So use it or don't, but I prefer this over seeing the warning/error.

If someone knows of a server-side syntactical workaround for this I would prefer this to the client-side one, so please add.

回答3:

I found that wrapping the Razor syntax in a JavaScript identity function also makes the IDE happy.

<script type="text/javascript">
    @* I stands for Identity *@
    function I(obj) { return obj; }
    $().ready(function(){
        var customer = I(@Html.Raw(ViewBag.CustomerJSON));
    });
</script>

回答4:

This worked for me:

var customer = @Html.Raw(ViewBag.CustomerJSON + ";")

回答5:

Here's a workaround for booleans:

var myBool = @(Model.MyBool ? "true;" : "false;")

回答6:

This worked for me

@Html.Raw(string.Format("var customer = {0};", ViewBag.CustomerJSON));

回答7:

<script type="text/javascript">
    $().ready(function(){
        var customerName = ('@ViewBag.CustomerName');  // <- wrap in parens
    });
</script>

Isn't it as simple as wrapping in parentheses? Putting values through the console seem to work fine with no side effect.

It works for strings, but it still gives the error for non-quoted values, but I still like this for string values. For numbers you could just use parseInt('@Model.TotalResultCount', 10).