Webhook – connect Web APIs and SaaS services – .net / Java

I have been working in SAAS solutions for many years now and it is interesting to see how technologies are evolving & applications / web APIs are connecting to each other to get seamless & quick end to end integration between systems & organizations.

Webhook – A lightweight HTTP pattern providing a simple pub/sub model for wiring together Web APIs and SaaS services. It’s been an year that this new concept been introduced in my product (thanks to our great Architect) and I see lot of benefits with it.

• Now our product can send notifications to the subscribed customers for the predefined events that happens in the product.
• It’s also used to show the changes between two major statuses in our workflow system
• We also thought about using it to build reporting data warehouse instead of building warehouse using the typical approach of ETL/batch jobs.

So there may be many such usecases that one can think about to see whether this can fit. The first use case i.e. sending notification with data on an event is a very natural usecase that many products can use this. More examples …

• File has changed in Dropbox
• Code change has been committed in GitHub
• Payment has been initiated in PayPal
• Card has been created in Trello
• Post P1 bug to a slack group

References

• .NET – https://blogs.msdn.microsoft.com/webdev/2015/09/04/introducing-microsoft-asp-net-webhooks-preview/
• https://www.codeproject.com/Articles/576278/Webhooks-webhook-URLs-and-a-sample-implementation
• JAva sample – https://github.com/IntuitDeveloper/SampleApp-Webhooks-Java
• https://github.com/ashwanthkumar/slack-java-webhook

Testing it

• https://webhook.site/#/7da1fedf-2256-468b-b3a3-13236ad4dfff
• https://requestb.in/ (from https://mandrill.zendesk.com/hc/en-us/articles/205583247-How-to-Test-and-Debug-Webhooks)

 

Managing Entity Framework ObjectContext lifespan, ObjectStateManager,Tracing & Caching – Links

http://dotnetslackers.com/articles/ado_net/Managing-Entity-Framework-ObjectContext-lifespan-and-scope-in-n-layered-ASP-NET-applications.aspx

http://code.msdn.microsoft.com/EFProviderWrappers-c0b88f32

http://msdn.microsoft.com/en-us/library/system.data.objects.objectstatemanager.aspx

On setting the lazy loading attribute to true (Lazy loading property is on edmx file’s context object) helps to provide lazy loading of related entities data instead of loading them on the same time when the main entity is accessed.

Domain Oriented (Domain Driven Design) NLayered Architecture

http://microsoftnlayerapp.codeplex.com/

http://msdn.microsoft.com/es-es/architecture/en/

Browser to ASP.NET to Browser

I came across a nice article on what happens with web request from Browser to ASP.NET (IIS Server) to Browser …

http://www.west-wind.com/presentations/howaspnetworks/howaspnetworks.asp

Summary of event sequence …

•  IIS gets the request
• Looks up a script map extension and maps to aspnet_isapi.dll
• Code hits the worker process (aspnet_wp.exe in IIS5 or w3wp.exe in IIS6)
• .NET runtime is loaded
• IsapiRuntime.ProcessRequest() called by non-managed code
• IsapiWorkerRequest created once per request
• HttpRuntime.ProcessRequest() called with Worker Request
• HttpContext Object created by passing Worker Request as input
• HttpApplication.GetApplicationInstance() called with Context to retrieve instance from pool
• HttpApplication.Init() called to start pipeline event sequence and hook up modules and handlers
• HttpApplicaton.ProcessRequest called to start processing
• Pipeline events fire
• Handlers are called and ProcessRequest method are fired
• Control returns to pipeline and post request events fire