How to Call a Post Handler from an AJAX Render Function in ASP.NET Core

Learn how to correctly invoke a POST handler from an AJAX function while passing values without exposing them in the URL.
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How to Call a Post Handler from an AJAX Render Function in ASP.NET Core

When working with ASP.NET Core, particularly in Razor Pages, you might encounter a situation where you want to trigger a POST handler from an AJAX function without appending sensitive IDs in the URL. This guide will guide you through the necessary steps to achieve this, ensuring that your application remains secure and user-friendly.

The Problem

Suppose you've implemented a DataTable that displays various records, and you want to allow users to trigger a post request when clicking a button to save changes or view more details. The issue arises when, upon click, your AJAX call defaults to a GET request instead of the desired POST request. Let's take a look at a sample code to understand the situation:

[[See Video to Reveal this Text or Code Snippet]]

As per your requirement, you want to call a specific POST handler from the DataTable without exposing the ID in the URL.

The Solution

There are a couple of important adjustments you need to make within your code. Here’s how to set it up correctly:

1. Update the DataTable’s Columns Definition

Instead of using the ASP.NET Core tag helper, it’s best to directly write the HTML form within the JavaScript rendering function. This provides more control over the elements. Here’s the modified DataTable initialization:

[[See Video to Reveal this Text or Code Snippet]]

2. Include AntiForgeryToken

Ensure that your forms contain an AntiForgeryToken to protect against CSRF (Cross-Site Request Forgery) attacks. You can do this by rendering the token in a hidden div, and appending it to each form upon initialization:

HTML

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JavaScript

You will need to include the AntiForgeryToken in your forms like this:

[[See Video to Reveal this Text or Code Snippet]]

3. Update the POST Handler

Finally, ensure your post handler can handle the incoming ID. Make sure your handler accepts the ID passed from the form:

[[See Video to Reveal this Text or Code Snippet]]

Conclusion

By adjusting the way you create your forms within the DataTable and incorporating the necessary AntiForgeryToken, you’ll effectively call a POST handler from your AJAX render function while keeping sensitive information secure. This approach not only enhances user interaction but also adheres to security best practices in web development.

With this guidance, you're now equipped to implement a seamless interaction between your DataTable and Razor Pages in ASP.NET Core. Happy coding!