Mixing JavaScript and Razor syntax

Question

I was looking for how to mix razor and JavaScript together. I found something like this:

<script type="text/javascript">
var currentUser = null;
@if (User.Identity.IsAuthenticated) {
    <text>
        currentUser = '@User.Identity.Name';
    </text>
}
</script>

Why is the variable called currentUser surrounded with <text></text> tag? What is the meaning of <text> tag? If we omit that text tag then any error occur?

Answer 1

Well, this is how razor works. It uses brackets and tags begin/end to differenciate c# code from generated HTML

When you open a bracket, it it considered code until :

• a corresponding closing bracket is encounterd
• a tag is opened.

Then , opened tag will be considered html until a@ or correspoding closing tag is encountered. Sometimes, you want to switch from c# to HTML (or js) but you don't want to add a tag... then special tag id there for you. It is not rendered, just here to tell razor to switch rom C# to generated output

Answer 2

The reason for the <text>…</text> tags is to solve the issue of ambiguities that arise as a result of your mixing two languages together that are semantically identical in many cases.

If you were to specify dynamic java script logic within the Razor syntax's C# if statements, and you had java script if statements in those blocks, how would it differentiate the context between the two?

The problem is: it can't; odds are, programmers can't either. The <text>…</text> tag is a special Razor block (inside C# blocks only) style escape that says: this is definitely (probably) not C# code that is in this block.

Things get a bit dicey when you realize you can then add another escape inside the <text>…</text> block. Like anything though you would use it with caution. If you're having a lot of trouble mixing the two and can't figure out where to add your text blocks, odds are you shouldn't be using it (in production) until you understand it better.