WebEventSink.cs

using System;
using System.Collections.Generic;
using System.Threading.Tasks;
using Waher.Content;
using Waher.Content.Xml;
using Waher.Events;
using Waher.Security;
 
namespace Waher.IoTGateway.WebResources
{
    public class WebEventSink : EventSink
    {
        private readonly DateTime created = DateTime.Now;
        private readonly DateTime expires;
        private readonly string[] privileges;
        private readonly string userVariable;
        private readonly string resource;
        private string[] tabIds = null;
        private DateTime tabIdTimestamp = DateTime.MinValue;
 
        public WebEventSink(string SinkId, string PageResource, TimeSpan MaxLife, string UserVariable, params string[] Privileges)
            : base(SinkId)
        {
            this.expires = DateTime.Now.Add(MaxLife);
            this.resource = PageResource;
            this.tabIds = null;
            this.userVariable = UserVariable;
            this.privileges = Privileges;
        }
 
        public override async Task Queue(Event Event)
        {
            try
            {
                DateTime Now = DateTime.Now;
 
                if ((Now - this.tabIdTimestamp).TotalSeconds > 2 || this.tabIds is null || this.tabIds.Length == 0)
                {
                    this.tabIds = ClientEvents.GetTabIDsForLocation(this.resource, true);
                    this.tabIdTimestamp = Now;
                }
 
                Dictionary<string, object>[] Tags;
 
                if (Event.Tags is null)
                    Tags = null;
                else
                {
                    int i, c = Event.Tags.Length;
                    Tags = new Dictionary<string, object>[c];
 
                    for (i = 0; i < c; i++)
                    {
                        Tags[i] = new Dictionary<string, object>()
                        {
                            { "name", Event.Tags[i].Key },
                            { "value", Event.Tags[i].Value }
                        };
                    }
                }
 
                string Data = JSON.Encode(new KeyValuePair<string, object>[]
                {
                    new KeyValuePair<string, object>("date", XML.Encode(Event.Timestamp.Date,true)),
                    new KeyValuePair<string, object>("time", Event.Timestamp.TimeOfDay.ToString()),
                    new KeyValuePair<string, object>("type", Event.Type.ToString()),
                    new KeyValuePair<string, object>("level", Event.Level.ToString()),
                    new KeyValuePair<string, object>("id", Event.EventId),
                    new KeyValuePair<string, object>("object", Event.Object),
                    new KeyValuePair<string, object>("actor", Event.Actor),
                    new KeyValuePair<string, object>("module", Event.Module),
                    new KeyValuePair<string, object>("facility", Event.Facility),
                    new KeyValuePair<string, object>("message", Event.Message),
                    new KeyValuePair<string, object>("stackTrace", Event.StackTrace),
                    new KeyValuePair<string, object>("tags", Tags)
                }, false);
 
                int Tabs = await ClientEvents.PushEvent(this.tabIds, "NewEvent", Data, true, this.userVariable, this.privileges);
 
                if (Now >= this.expires || (Tabs <= 0 && (Now - this.created).TotalSeconds >= 5))
                {
                    await ClientEvents.PushEvent(this.tabIds, "SinkClosed", string.Empty, false, this.userVariable, this.privileges);
 
                    Log.Unregister(this);
                    this.Dispose();
                }
            }
            catch (Exception ex)
            {
                Log.Exception(ex);
            }
        }
    }
}