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Processing

Overview​

Support for CQS pattern on domain implementation.

Install​

  • ASOL.Core.Processing - contains CQS processing providers like CommandProcessor, QueryProcessor. Use this package when implementing processing.
  • ASOL.Core.Processing.Abstractions - contains processing interfaces like ICommandProcessor, IQueryProcessor, ICommandHandler, IQueryHandler. Use this package when using processing.
  • ASOL.Core.Processing.Primitives - contains processing primitives like ICommand, IQuery. Use this package when defining processing contracts.

Changelog​

  • 0.0.1.45802-dev
    • Support for Application Insights has been removed; OpenTelemetry is now used instead. For proper functioning, the minimum required version of ASOL.Core.Telemetry.Client is 0.0.1.45792-dev.

Dependency injection​

Mandatory dependency injection for CQS pattern.

/// <summary>
/// Add CQS infrastructure and all commands, queries and their handlers.
/// </summary>
/// <param name="services"></param>
/// <returns></returns>
public static IServiceCollection AddProcessingQueryAndCommands(this IServiceCollection services)
        {
            // Register all command handlers and query handlers and connect with their commands and queries.
            services.Scan(scan =>
            {
                scan.FromAssembliesOf(typeof(BookCreateCommand))
                    .AddClasses(classes => classes.AssignableTo(typeof(ICommandHandler<,>)))
                        .AsImplementedInterfaces()
                        .WithTransientLifetime();
                scan.FromAssembliesOf(typeof(BookCreateCommand))
                    .AddClasses(classes => classes.AssignableTo(typeof(ICommandHandler<>)))
                        .AsImplementedInterfaces()
                        .WithTransientLifetime();
                scan.FromAssembliesOf(typeof(GetAllBooksQuery))
                    .AddClasses(classes => classes.AssignableTo(typeof(IQueryHandler<,>)))
                        .AsImplementedInterfaces()
                        .WithTransientLifetime();
            });

            // Register mandantory implementation.
            services.AddScoped<ICommandHandlerProvider, CommandHandlerProvider>();
            services.AddScoped<ICommandProcessor, CommandProcessor>();
            services.AddScoped<IQueryHandlerProvider, QueryHandlerProvider>();
            services.AddScoped<IQueryProcessor, QueryProcessor>();
            return services;
        }

Metrics​

Each processed command and query (successful and unsuccessful) is counted using System.Diagnostics.Metrics.Counter metric.
Name of the counters:

  • asol.core.processing.command.success
  • asol.core.processing.command.failed
  • asol.core.processing.query.success
  • asol.core.processing.query.failed

The source of metrics is stored in the library ASOL.Core.Telemetry.Client.