DNTCaptcha.Core

Choosing a storage provider depends on your deployment architecture:

• Distributed/Stateless Environments (e.g., Azure Web Roles, Kubernetes): Avoid UseSessionStorageProvider() or UseMemoryCacheStorageProvider() because session state is stored in local RAM and will be lost if the instance moves or restarts. Instead, use UseCookieStorageProvider() or UseDistributedCacheStorageProvider() (e.g., with Redis) to ensure state persists across different server instances.

To run the full demonstration environment consisting of the DNTCaptcha.TestApiApp backend and the DntCaptchaAngularClient frontend, follow these steps:

1. Start the Backend: Run the DNTCaptcha.TestApiApp project using your IDE (Visual Studio or Rider) or via the CLI using dotnet watch run.
2. Install Frontend Dependencies: Navigate to the DNTCaptcha.AngularClient/ directory and run npm install.
3. Start the Frontend: Inside the DNTCaptcha.AngularClient/ directory, execute ng serve or npm run start.
4. Access the App: Open your browser and navigate to http://localhost:4200.

Note: The Angular client is designed to work with the DNTCaptcha.TestApiApp backend.

# 1. Start backend
dotnet watch run

# 2. Install frontend dependencies
cd DNTCaptcha.AngularClient/
npm install

# 3. Start frontend
ng serve

By default, the plugin outputs error messages in a <label> element. To improve screen reader support and avoid having multiple <label> elements for a single input, use the errorElement parameter in the validate() method.

When you specify an element (e.g., "span"), the plugin automatically adds aria-describedby to the input field and links it to the error element, ensuring better programmatic association for assistive technologies.

```js
// Configuration
$("#myform").validate({
  errorElement: "span"
});

<!-- Resulting HTML Structure --> <label for="name">Name</label> <input id="name" aria-describedby="unique-id-here"> <span class="error" id="unique-id-here">This field is required</span>

The jQuery Validation Plugin provides drop-in validation for existing forms. You can download prebuilt files from jqueryvalidation.org or obtain the latest development files by building the repository using grunt.

To use the plugin, include both jQuery and jquery.validate.js on your page, then call the .validate() method on your form selector.

<form>
	<input required>
</form>
<script src="jquery.js"></script>
<script src="jquery.validate.js"></script>
<script>
    $("form").validate();
</script>

If your application is running behind a reverse proxy (like a load balancer), you must add the forwarded headers middleware to ensure correct request processing. Configure ForwardedHeadersOptions with the appropriate headers and known proxy IP addresses.

services.Configure<ForwardedHeadersOptions>(options =>
{
  options.ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto;
  options.KnownProxies.Add(IPAddress.Parse("my load balancer ip 1"));
  options.KnownProxies.Add(IPAddress.Parse("my load balancer ip 2"));
});

DNTCaptcha is compatible with modern Single Page Application (SPA) architectures:

• Angular: Use the dntcaptcha-angular-client package. A sample implementation includes a server-side controller, a dedicated Angular component, and a login component integration.
• Pure JavaScript: The library can be used with any pure JavaScript application via API calls.