HRCenter/Diligent.WebAPI.Business/Services/WebhookPublisherService.cs

namespace Diligent.WebAPI.Business.Services
{
    public class WebhookPublisherService : IWebhookPublisherService
    {
        private readonly IWebhookSubscriptionService _subscriptionService;

        public WebhookPublisherService(IWebhookSubscriptionService subscriptionService)
        {
            _subscriptionService = subscriptionService;
        }

        public async Task PublishAsync(string webhookName, object data)
        {
            // Get all subscriptions
            var subscriptions = await _subscriptionService.GetAllSubscriptionsAsync(webhookName);

            if (subscriptions == null || subscriptions.Count == 0)
                return;

            // Send POST request to subscriptions
            
            // 1: define POST request
            var request = new RestRequest("", Method.Post);
            // 2: define request body
            var serializedOrder = JsonConvert.SerializeObject(data, new JsonSerializerSettings { NullValueHandling = NullValueHandling.Ignore });
            request.AddJsonBody(serializedOrder);
            // 3: define request headers
            request.AddHeader("Content-Type", "application/json");

            foreach (var subscription in subscriptions)
            {
                try
                {
                    // 4: define client endpoint
                    var client = new RestClient(subscription.WebhookURL);
                    // 5: send
                    await client.ExecuteAsync(request);
                }
                catch (Exception)
                {
                    // if one subscription fail continue
                }
            }
        }
    }
}