PollingFilterWatchToken

PollingFilterWatchToken(fileProvider, filterPath, pollInterval) is a single use polling file monitor. It detects file additions, deletions and modifications.

// File pattern to monitor
string filterPath = "**/*.txt";
// Create IFileProvider
IFileProvider fileProvider = new PhysicalFileProvider(Directory.GetCurrentDirectory());
// Create initial token
IChangeToken token = new PollingFilterWatchToken(fileProvider, filterPath, TimeSpan.FromSeconds(0.5));
// Place here callback
Action<object?>[] callbacks = new Action<object?>[1];
// Place here subscription
IDisposable[] subscriptions = new IDisposable[1];
// Create callback
callbacks[0] = o =>
{
    // File has been modified
    Console.WriteLine($"Modified ({token.HasChanged})");
    // Create new monitor
    var _token = new PollingFilterWatchToken(fileProvider, filterPath, TimeSpan.FromSeconds(0.5));
    // Register new token
    subscriptions[0] = _token.RegisterChangeCallback(callbacks[0], null);
};
// Register callback
subscriptions[0] = token.RegisterChangeCallback(callbacks[0], null);
// Monitor file changes until key is pressed
Console.WriteLine($"Monitoring file changes \"{filterPath}\". Press key to stop monitoring.");
Console.ReadKey();
subscriptions[0].Dispose();

Full Example

Full example

using Avalanche.FileSystem;
using Microsoft.Extensions.FileProviders;
using Microsoft.Extensions.Primitives;

public class pollingfilterwatchtoken
{
    public static void Run()
    {
        {
            // <01>
            // File pattern to monitor
            string filterPath = "**/*.txt";
            // Create IFileProvider
            IFileProvider fileProvider = new PhysicalFileProvider(Directory.GetCurrentDirectory());
            // Create initial token
            IChangeToken token = new PollingFilterWatchToken(fileProvider, filterPath, TimeSpan.FromSeconds(0.5));
            // Place here callback
            Action<object?>[] callbacks = new Action<object?>[1];
            // Place here subscription
            IDisposable[] subscriptions = new IDisposable[1];
            // Create callback
            callbacks[0] = o =>
            {
                // File has been modified
                Console.WriteLine($"Modified ({token.HasChanged})");
                // Create new monitor
                var _token = new PollingFilterWatchToken(fileProvider, filterPath, TimeSpan.FromSeconds(0.5));
                // Register new token
                subscriptions[0] = _token.RegisterChangeCallback(callbacks[0], null);
            };
            // Register callback
            subscriptions[0] = token.RegisterChangeCallback(callbacks[0], null);
            // Monitor file changes until key is pressed
            Console.WriteLine($"Monitoring file changes \"{filterPath}\". Press key to stop monitoring.");
            Console.ReadKey();
            subscriptions[0].Dispose();
            // </01>
        }
    }
}