{"id":28202,"date":"2025-12-21T09:49:08","date_gmt":"2025-12-21T09:49:08","guid":{"rendered":"https:\/\/www.gencayyildiz.com\/blog\/?p=28202"},"modified":"2025-12-21T09:49:08","modified_gmt":"2025-12-21T09:49:08","slug":"mediatr-yerine-martinothamar-mediator-kutuphanesini-inceleyelim","status":"publish","type":"post","link":"https:\/\/www.gencayyildiz.com\/blog\/mediatr-yerine-martinothamar-mediator-kutuphanesini-inceleyelim\/","title":{"rendered":"MediatR Yerine ‘martinothamar\/Mediator’ K\u00fct\u00fcphanesini \u0130nceleyelim"},"content":{"rendered":"

<\/div>\n

Merhaba,<\/p>\n

Bu i\u00e7eri\u011fimizde MediatR<\/a> k\u00fct\u00fcphanesine alternatif olarak de\u011ferlendirebilece\u011fimiz martinothamar\/Mediator<\/em> k\u00fct\u00fcphanesini hem teorik hem de pratik olarak inceleyecek, MediatR yerine nas\u0131l konumland\u0131\u011f\u0131n\u0131 en net \u015fekilde ele al\u0131yor olaca\u011f\u0131z.<\/p>\n

*martinothamar\/Mediator Nedir?<\/h4>\n**martinothamar\/Mediator<\/em>, .NET d\u00fcnyas\u0131nda MediatR’a bir alternatif olarak geli\u015ftirilen lightweight, performans odakl\u0131 ve allocation-free olan bir* Mediator Pattern<\/a> implementasyonu k\u00fct\u00fcphanesidir. MediatR’a \u00e7ok benzer API yap\u0131s\u0131na sahip olsa da daha modern, source-generator altyap\u0131s\u0131na sahip ve AOT<\/a> dostu bir yap\u0131ya sahiptir.<\/p>\n
Amac\u0131;<\/p>\n
\n
Request\/Response i\u015f ak\u0131\u015flar\u0131n\u0131 desteklemek,<\/li>\n
Notification\/Publish-Subscribe olay ak\u0131\u015flar\u0131n\u0131 desteklemek,<\/li>\n
Pipeline davran\u0131\u015flar\u0131n\u0131 desteklemektir.<\/li>\n<\/ul>\n
Ana \u00f6zellikleri ise;<\/p>\n
\n
Source generator (compile-time code generation) kullanabilmektedir.<\/li>\n
Native AOT senaryolar\u0131na \u00f6zellikle uyumlu olacak \u015fekilde tasarlanm\u0131\u015ft\u0131r.<\/li>\n
Reflection kullanmadan dependency injection registry i\u015flemini ve IMediator implementasyonunu compile-time’da \u00fcretebilmektedir.<\/li>\n<\/ul>\n
Kim taraf\u0131ndan geli\u015ftirilmi\u015ftir?<\/strong>
\nK\u00fct\u00fcphanenin ana geli\u015ftiricisi Martin Othamar<\/em> abimizdir. GitHub reposuda https:\/\/github.com\/martinothamar\/Mediator<\/a> adresindedir.<\/p>\n
.NET’de Kullan\u0131m\u0131<\/h4>\n
Mediator k\u00fct\u00fcphanesini kullanabilmek i\u00e7in \u00f6ncelikle gerekli paketleri
\n dotnet add package Mediator.Abstractions<\/a>
\nve
\n dotnet add package Mediator.SourceGenerator<\/a>
\ntalimatlar\u0131 e\u015fli\u011finde ilgili projeye y\u00fckleyiniz.<\/p>\n
Ard\u0131ndan Mediator yap\u0131lar\u0131n\u0131 projeye dahil edebilmek i\u00e7in a\u015fa\u011f\u0131daki gibi servis entegrasyonunu ger\u00e7ekle\u015ftiriniz:<\/p>\n
\n
\r\nvar builder = WebApplication.CreateBuilder(args);\r\n\r\nbuilder.Services.AddMediator();\r\n\r\nvar app = builder.Build();\r\n<\/pre>\n<\/div>\n
Bu i\u015flemlerden sonra CQRS<\/em>, Notification<\/em> veya Pipeline Behavior<\/em> davran\u0131\u015flar\u0131ndan hangisini uygulamak istiyorsan\u0131z a\u015fa\u011f\u0131daki gibi \u00e7al\u0131\u015fmalar ger\u00e7ekle\u015ftirebilirsiniz:<\/p>\n
\n
CQRS<\/em><\/strong>
\n $\"MediatR$ <\/a>CQRS pattern’\u0131 uygularken birebir MediatR<\/a> k\u00fct\u00fcphanesinde oldu\u011fu gibi Command ve Query’ler fiziksel ayr\u0131lmal\u0131 ve Request \/ Response<\/em> implementasyonlar\u0131 e\u015fli\u011finde davran\u0131\u015flar olu\u015fturulmal\u0131d\u0131r.<\/p>\n
\u00d6rnek Command \u00e7al\u0131\u015fmas\u0131;<\/p>\n
\n
\r\n public sealed record CreateUserCommandRequest(string FirstName, string LastName) : IRequest<CreateUserCommandResponse>;\r\n<\/pre>\n<\/div>\n
\n
\r\n public sealed record CreateUserCommandResponse(Guid Id);\r\n<\/pre>\n<\/div>\n
\n
\r\n public sealed class CreateUserCommandHandler : IRequestHandler<CreateUserCommandRequest, CreateUserCommandResponse>\r\n {\r\n public async ValueTask<CreateUserCommandResponse> Handle(CreateUserCommandRequest request, CancellationToken cancellationToken)\r\n {\r\n await Console.Out.WriteLineAsync($"'{request.FirstName} {request.LastName}' created");\r\n var id = Guid.NewGuid();\r\n return new CreateUserCommandResponse(id);\r\n }\r\n }\r\n<\/pre>\n<\/div>\n
\u00d6rnek Query \u00e7al\u0131\u015fmas\u0131;<\/p>\n
\n
\r\n public sealed record GetUsersQueryRequest : IRequest<GetUsersQueryResponse[]>;\r\n<\/pre>\n<\/div>\n
\n
\r\n public sealed record GetUsersQueryResponse(string FirstName, string LastName);\r\n<\/pre>\n<\/div>\n
\n
\r\n public sealed class GetUsersQueryHandler : IRequestHandler<GetUsersQueryRequest, GetUsersQueryResponse[]>\r\n {\r\n public ValueTask<GetUsersQueryResponse[]> Handle(GetUsersQueryRequest request, CancellationToken cancellationToken)\r\n {\r\n return ValueTask.FromResult(new[]\r\n {\r\n new GetUsersQueryResponse("Ahmet", "Y\u0131lmaz"),\r\n new GetUsersQueryResponse("\u0130brahim", "Y\u0131lmaz"),\r\n new GetUsersQueryResponse("C\u00fcneyt", "Y\u0131ld\u0131z"),\r\n new GetUsersQueryResponse("Mustafa", "Y\u0131ld\u0131z")\r\n });\r\n }\r\n }\r\n<\/pre>\n<\/div>\n
Her iki \u00e7al\u0131\u015fmay\u0131 da kullan\u0131rken a\u015fa\u011f\u0131daki gibi basit endpoint’lerden istifade edebilir ve testimizi ger\u00e7ekle\u015ftirebiliriz;<\/p>\n
\n
\r\napp.MapGet("\/get-users", async (IMediator mediator, [AsParameters] GetUsersQueryRequest getUsersQueryRequest) => await mediator.Send(getUsersQueryRequest));\r\n\r\napp.MapPost("\/create-user-command", async (IMediator mediator, CreateUserCommandRequest createUserCommandRequest) => await mediator.Send(createUserCommandRequest));\r\n<\/pre>\n<\/div>\n<\/li>\n
Notification<\/em><\/strong>
\nNotification’da da ayn\u0131 al\u0131\u015f\u0131lageldik mant\u0131kla hareket edilmekte ve INotification<T><\/code> ve INotificationHandler<T><\/code> aray\u00fczlerinden istifade edilmektedir.<\/p>\n\u015e\u00f6yle ki;<\/p>\n Bir notification tan\u0131m\u0131 tasarlanmal\u0131;<\/p>\n \n\r\npublic sealed record UserCreatedNotification(Guid UserId) : INotification;\r\n<\/pre>\n<\/div>\nVe akabinde bu tan\u0131m\u0131 kar\u015f\u0131layacak a\u015fa\u011f\u0131daki gibi bir veya birden fazla handler olu\u015fturulmal\u0131d\u0131r;<\/p>\n \n\r\n public class SendEmailOnUserCreatedHandler : INotificationHandler<UserCreatedNotification>\r\n {\r\n public ValueTask Handle(UserCreatedNotification notification, CancellationToken ct)\r\n {\r\n Console.WriteLine("Email sent: " + notification.UserId);\r\n return ValueTask.CompletedTask;\r\n }\r\n }\r\n<\/pre>\n<\/div>\n\n\r\n public class LogUserCreatedHandler : INotificationHandler<UserCreatedNotification>\r\n {\r\n public ValueTask Handle(UserCreatedNotification notification, CancellationToken ct)\r\n {\r\n Console.WriteLine("Log: User created " + notification.UserId);\r\n return ValueTask.CompletedTask;\r\n }\r\n }\r\n<\/pre>\n<\/div>\nBu \u00e7al\u0131\u015fmay\u0131 da test edebilmek i\u00e7in CQRS \u00f6rne\u011finde olu\u015fturdu\u011fumuz POST endpoint’ini a\u015fa\u011f\u0131daki gibi geni\u015fletebiliriz;<\/p>\n \n\r\napp.MapPost("\/create-user-command", async (IMediator mediator, CreateUserCommandRequest createUserCommandRequest) =>\r\n{\r\n var response = await mediator.Send(createUserCommandRequest);\r\n await mediator.Publish(new UserCreatedNotification(response.Id));\r\n return response;\r\n});\r\n<\/pre>\n<\/div>\n<\/li>\nPipeline Behavior<\/em><\/strong> \nLogging, validation ve caching i\u015flemleri i\u00e7in de Pipeline Behavior davran\u0131\u015flar\u0131ndan a\u015fa\u011f\u0131daki gibi faydalanabilmekteyiz.<\/p>\n\nLogging<\/u><\/em>\n\n\r\n public class LoggingPipelineBehavior<TMessage, TResponse>(ILogger<LoggingPipelineBehavior<TMessage, TResponse>> logger) : IPipelineBehavior<TMessage, TResponse> where TMessage : notnull, IMessage\r\n {\r\n public async ValueTask<TResponse> Handle(TMessage message, MessageHandlerDelegate<TMessage, TResponse> next, CancellationToken cancellationToken)\r\n {\r\n logger.LogInformation(\r\n "Handling {RequestName} with data {@Request}",\r\n typeof(TMessage).Name,\r\n message);\r\n\r\n var response = await next(message, cancellationToken);\r\n\r\n logger.LogInformation(\r\n "Handled {RequestName} with response {@Response}",\r\n typeof(TMessage).Name,\r\n response);\r\n\r\n return response;\r\n }\r\n }\r\n<\/pre>\n<\/div>\n<\/li>\nValidation<\/u><\/em>\n\n\r\n public class CreateUserCommandValidator : AbstractValidator<CreateUserCommandRequest>\r\n {\r\n public CreateUserCommandValidator()\r\n {\r\n RuleFor(x => x.FirstName)\r\n .NotEmpty()\r\n .WithMessage("FirstName bo\u015f ge\u00e7ilemez!")\r\n .MaximumLength(15)\r\n .MinimumLength(3);\r\n\r\n RuleFor(x => x.LastName)\r\n .NotEmpty()\r\n .WithMessage("LastName bo\u015f ge\u00e7ilemez!")\r\n .MaximumLength(15)\r\n .MinimumLength(3);\r\n }\r\n }\r\n<\/pre>\n<\/div>\n\n\r\n public sealed class ValidationPipelineBehavior<TMessage, TResponse>(IServiceProvider serviceProvider) : IPipelineBehavior<TMessage, TResponse> where TMessage : IMessage\r\n {\r\n public async ValueTask<TResponse> Handle(TMessage message, MessageHandlerDelegate<TMessage, TResponse> next, CancellationToken cancellationToken)\r\n {\r\n using var scope = serviceProvider.CreateScope();\r\n\r\n var validators = scope.ServiceProvider.GetServices<IValidator<TMessage>>().ToList();\r\n\r\n if (validators is [])\r\n return await next(message, cancellationToken);\r\n\r\n var context = new ValidationContext<TMessage>(message);\r\n\r\n var validationResults = await Task.WhenAll(validators.Select(async validator => await validator.ValidateAsync(context, cancellationToken)));\r\n\r\n var failures = validationResults\r\n .SelectMany(result => result.Errors)\r\n .Where(failure => failure != null)\r\n .ToList();\r\n\r\n if (failures is not [])\r\n throw new ValidationException(failures);\r\n\r\n return await next(message, cancellationToken);\r\n }\r\n }\r\n<\/pre>\n<\/div>\n<\/li>\nCaching<\/u><\/em>\n\n\r\n public class RedisService\r\n {\r\n ConnectionMultiplexer? connectionMultiplexer;\r\n public void Connect()\r\n => connectionMultiplexer = ConnectionMultiplexer.Connect("localhost:6379");\r\n public IDatabase Database\r\n {\r\n get\r\n {\r\n if (!connectionMultiplexer?.IsConnected == null)\r\n Connect();\r\n\r\n return connectionMultiplexer.GetDatabase(0);\r\n }\r\n }\r\n }\r\n<\/pre>\n<\/div>\n\n\r\n public sealed class CachingPipelineBehavior<TMessage, TResponse>(RedisService redisService) : IPipelineBehavior<TMessage, TResponse> where TMessage : IMessage where TResponse : class\r\n {\r\n public async ValueTask<TResponse> Handle(TMessage message, MessageHandlerDelegate<TMessage, TResponse> next, CancellationToken cancellationToken)\r\n {\r\n var redisDatabase = redisService.Database;\r\n\r\n var cacheKey = $"{message.GetType().FullName}";\r\n\r\n TResponse? cachedResponse = null;\r\n\r\n var cachedData = await redisDatabase.StringGetAsync(cacheKey);\r\n if (cachedData.HasValue)\r\n {\r\n var cachedResponseJson = Encoding.UTF8.GetString(cachedData);\r\n cachedResponse = JsonSerializer.Deserialize<TResponse>(cachedResponseJson);\r\n }\r\n\r\n if (cachedResponse != null)\r\n return cachedResponse;\r\n\r\n var response = await next(message, cancellationToken);\r\n\r\n \/\/Yeni veriyi cache'e al\u0131yoruz.\r\n var responseJson = JsonSerializer.Serialize(response);\r\n var encodedData = Encoding.UTF8.GetBytes(responseJson);\r\n\r\n var result = await redisDatabase.StringSetAsync(cacheKey, encodedData, expiry: TimeSpan.FromMinutes(60));\r\n return response;\r\n }\r\n<\/pre>\n<\/div>\n<\/li>\n<\/ul>\nTabi t\u00fcm bu Pipeline Behavior davran\u0131\u015flar\u0131n\u0131 sisteme dahil edebilmek i\u00e7in a\u015fa\u011f\u0131daki gibi bir yap\u0131land\u0131rmada bulunmak yeterli olacakt\u0131r:<\/p>\n \n\r\nbuilder.Services.AddMediator(options => options.PipelineBehaviors = [\r\n typeof(LoggingPipelineBehavior<,>),\r\n typeof(ValidationPipelineBehavior<,>),\r\n typeof(CachingPipelineBehavior<,>)\r\n ]);\r\n<\/pre>\n<\/div>\n<\/li>\n<\/ul>\nStreaming Messages<\/h4>\nSon olarak Mediator k\u00fct\u00fcphanesinin en az bilinen ama en g\u00fc\u00e7l\u00fc diyebilece\u011fim \u00f6zelli\u011fi olan Streaming Messages \u00f6zelli\u011fini de\u011ferlendirelim.<\/p>\n Bu \u00f6zellik; esas\u0131nda ad\u0131 \u00fczerinde, klasik CQRS davran\u0131\u015f\u0131ndaki handler’\u0131n tek bir response d\u00f6nd\u00fcrmesinden ziyade, zaman i\u00e7inde birden fazla sonu\u00e7 \u00fcretmesi (stream) \u00fczerine kurgulanm\u0131\u015f davran\u0131\u015flar i\u00e7in ge\u00e7erli bir \u00e7\u00f6z\u00fcm sa\u011flamaktad\u0131r.<\/p>\n A\u015fa\u011f\u0131daki \u00f6rne\u011fi incelerseniz e\u011fer;<\/p>\n \n\r\n public sealed record StreamRequest : IStreamRequest<StreamResponse>;\r\n<\/pre>\n<\/div>\n\n\r\n public sealed record StreamResponse(Guid Id);\r\n<\/pre>\n<\/div>\n\n\r\n public sealed class StreamHandler : IStreamRequestHandler<StreamRequest, StreamResponse>\r\n {\r\n public async IAsyncEnumerable<StreamResponse> Handle(StreamRequest request, CancellationToken cancellationToken)\r\n {\r\n for (int i = 0; i < 5; i++)\r\n {\r\n await Task.Delay(1000, cancellationToken);\r\n yield return new StreamResponse(Guid.NewGuid());\r\n }\r\n }\r\n }\r\n<\/pre>\n<\/div>\n\u015feklinde teknik bir kuyguyla rahatl\u0131kla uygulanabilmektedir.<\/p>\n Tabi kullan\u0131rken de a\u015fa\u011f\u0131daki gibi bir endpoint’ten istifade edilebilir:<\/p>\n \n\r\napp.MapGet("\/streaming-messages", async (IMediator mediator, [AsParameters] StreamRequest streamRequest) =>\r\n{\r\n await foreach (var response in mediator.CreateStream(streamRequest))\r\n Console.WriteLine(response);\r\n});\r\n<\/pre>\n<\/div>\nFark\u0131ndaysan\u0131z esas\u0131nda bu \u00f6zelli\u011fin t\u00fcm altyap\u0131s\u0131 .NET’teki asenkron iterasyonel i\u015flevlerin temeli olan IAsyncEnumerable<T><\/code><\/a> interface’ine g\u00f6re yap\u0131land\u0131r\u0131lm\u0131\u015ft\u0131r. Haliyle par\u00e7a par\u00e7a veri aktar\u0131mlar\u0131 s\u00fcre\u00e7lerinde CQRS benimsenmi\u015fse e\u011fer bu streamin \u00f6zelli\u011fi ile h\u0131zl\u0131ca gerekli aksiyonlar al\u0131nabilecektir. B\u00f6ylece, \u00f6zellikle b\u00fcy\u00fck veri setlerinde, uzun s\u00fcren i\u015flemlerde ve real-time ak\u0131\u015flarda ihtiyac\u0131 kar\u015f\u0131layabilecek muazzam bir altyap\u0131 elimizin alt\u0131ndad\u0131r diyebiliriz. Bir yandan, bu \u00f6zellik ile ilgili k\u00fct\u00fcphanenin MediatR’a fark yaratt\u0131\u011f\u0131n\u0131 da s\u00f6yleyebiliriz.<\/p>\n Nihai olarak;<\/p>\n MediatR \u00fccretli olduktan sonra CQRS gibi \u00f6nemli bir pattern’\u0131 manuel uygulamay\u0131 \u00f6neren onlarca tavsiyeden sonra (ki bu pattern’\u0131n nas\u0131l manuel uygulanaca\u011f\u0131na dair teknik makaleyi y\u0131llar \u00f6nce ilk kaleme alan ki\u015fi olarak diyorum ki) martinothamar\/Mediator k\u00fct\u00fcphanesinin ayn\u0131 kullan\u0131m pratikleri e\u015fli\u011finde daha elveri\u015fli bir altyap\u0131 sa\u011flad\u0131\u011f\u0131n\u0131 s\u00f6yleyebilirim.<\/p>\n \u0130lgilenenlerin faydalanmas\u0131 dile\u011fiyle… \nSonraki yaz\u0131lar\u0131mda g\u00f6r\u00fc\u015fmek \u00fczere… \n\u0130yi \u00e7al\u0131\u015fmalar…<\/p>\n Not : \u00d6rnek \u00e7al\u0131\u015fmaya a\u015fa\u011f\u0131daki GitHub adresinden eri\u015febilirsiniz. \nhttps:\/\/github.com\/gncyyldz\/CQRS_With_martinothamar_Mediator_Example<\/a><\/p>\n","protected":false},"excerpt":{"rendered":" Merhaba, Bu i\u00e7eri\u011fimizde MediatR k\u00fct\u00fcphanesine alternatif olarak de\u011ferlendirebilece\u011fimiz martinothamar\/Mediator k\u00fct\u00fcphanesini hem teorik hem de pratik olarak inceleyecek, MediatR yerine nas\u0131l konumland\u0131\u011f\u0131n\u0131 en net \u015fekilde ele al\u0131yor olaca\u011f\u0131z. martinothamar\/Mediator Nedir? martinothamar\/Mediator, .NET d\u00fcnyas\u0131nda MediatR’a bir...<\/p>\n","protected":false},"author":1,"featured_media":3223,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[5206,2739,3102],"tags":[4150,5548,5549,5550,5551,4153,1265,5552,5553],"class_list":["post-28202","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-net","category-net-core","category-asp-net-core","tag-cqrs","tag-cqrs-martinothamar-mediator","tag-cqrs-mediator","tag-martinothamar-mediator","tag-martinothamar-mediator-nedir","tag-mediatr","tag-notification","tag-pipeline-behavior","tag-streaming-messages"],"amp_enabled":true,"_links":{"self":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/28202","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/comments?post=28202"}],"version-history":[{"count":7,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/28202\/revisions"}],"predecessor-version":[{"id":28214,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/posts\/28202\/revisions\/28214"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media\/3223"}],"wp:attachment":[{"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/media?parent=28202"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/categories?post=28202"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.gencayyildiz.com\/blog\/wp-json\/wp\/v2\/tags?post=28202"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}