SemanticModule.cs

using System;
using System.Threading.Tasks;
using Waher.Content.Semantic;
using Waher.IoTGateway;
using Waher.Networking.HTTP;
using Waher.Runtime.Inventory;
using Waher.Runtime.Language;
using Waher.Things.Semantic.Sources;
 
namespace Waher.Things.Semantic
{
    public class SemanticModule : IModule
    {
        public Task Start()
        {
            Gateway.Root.FileNotFound += this.CheckDynamicGraphs;
            return Task.CompletedTask;
        }
 
        public Task Stop()
        {
            Gateway.Root.FileNotFound -= this.CheckDynamicGraphs;
            return Task.CompletedTask;
        }
 
        private async Task CheckDynamicGraphs(object Sender, FileNotFoundEventArgs e)
        {
            if (e.Exception is null)
                return;     // Already processed.
 
            RequestOrigin Caller;
 
            if (e.Request.User is IRequestOrigin Origin)
                Caller = await Origin.GetOrigin();
            else
                Caller = RequestOrigin.Empty;
 
            IDynamicGraph Graph = await DataSourceGraph.FindDynamicGraph(e.Request.SubPath, Caller);
            if (Graph is null)
                return;
 
            e.Exception = null;
 
            _ = Task.Run(async () =>
            {
                try
                {
 
                    InMemorySemanticCube Result = new InMemorySemanticCube();
                    Language Language = await Translator.GetDefaultLanguageAsync();  // TODO: Check Accept-Language HTTP header.
 
                    await Graph.GenerateGraph(Result, Language, Caller);
                    await e.Response.Return(Result);
                }
                catch (Exception ex)
                {
                    await e.Response.SendResponse(ex);
                }
                finally
                {
                    await e.Response.DisposeAsync();
                }
            });
        }
    }
}