Using Razor, how do I render a Boolean to a JavaScript variable?

How to Render a Boolean to a JavaScript Variable Using Razor

💡 Have you ever encountered a syntax error when trying to render a Boolean value to a JavaScript variable in a .cshtml file? Don't worry, you're not alone! In this blog post, we'll address this common issue and provide easy solutions to help you overcome it. Let's dive in! 🚀

The Problem

🤔 So, what's the problem here? The issue lies in mixing server-side C# code with client-side JavaScript code in the Razor view engine. When you try to assign a C# Boolean value directly inside a JavaScript variable, it throws a syntax error. This happens because Razor tries to interpret the Boolean value as JavaScript code, resulting in an invalid assignment.

🚫 Take a look at the code snippet below:

<script type="text/javascript">
    var myViewModel = {
        isFollowing: @Model.IsFollowing // This is a C# bool
    };
</script>

⛔️ This will likely generate a syntax error in your .cshtml file. Now, let's explore some easy solutions to solve this problem!

Solution 1: Using the @Html.Raw() Method

✅ One way to overcome the syntax error is by using the @Html.Raw() method, which prevents Razor from interpreting the Boolean value as JavaScript code. Follow the example below:

<script type="text/javascript">
    var myViewModel = {
        isFollowing: @Html.Raw(Json.Encode(Model.IsFollowing)) // This is a C# bool
    };
</script>

👉 By using @Html.Raw(), we can safely encode the Boolean value without triggering a syntax error. This ensures that Razor simply outputs the Boolean without any unnecessary interpretation.

Solution 2: Transforming the Boolean Value

✅ Another solution is to transform the Boolean value into a string or integer explicitly. This way, the Razor engine won't get confused and can successfully render the value as expected. Check out this example:

<script type="text/javascript">
    var myViewModel = {
        isFollowing: @(Model.IsFollowing ? "true" : "false") // This is a C# bool
    };
</script>

👉 By using the ternary operator ? :, we convert the Boolean value into the corresponding string representation that JavaScript understands as a Boolean.

Solution 3: Utilizing JSON Serialization

✅ Lastly, you can utilize JSON serialization to convert the Boolean value into a format that can be easily assigned to a JavaScript variable. Follow this example:

@{
    var serializedBool = Newtonsoft.Json.JsonConvert.SerializeObject(Model.IsFollowing);
}

<script type="text/javascript">
    var myViewModel = {
        isFollowing: @Html.Raw(serializedBool)
    };
</script>

👉 Here, we use the SerializeObject() method from the popular JSON serialization library Newtonsoft.Json to convert the Boolean value into a JSON-encoded string. Then, we can safely render it into the JavaScript variable without any syntax errors.

Conclusion

🎉 That's it! You've learned three easy solutions to render a Boolean value to a JavaScript variable using Razor. You can either use the @Html.Raw() method, transform the Boolean value explicitly, or utilize JSON serialization. Choose the solution that fits your needs best and say goodbye to those pesky syntax errors!

💬 We'd love to hear your thoughts. Have you experienced this issue before? Which solution worked best for you? Share your experiences and join the discussion in the comments below! 👇