DES.App 3.7.0.62

DES Overview

DES is an enterprise-grade platform for executing, tracking, and managing dynamic workflows. It provides a robust, scalable architecture for processing data exchanges with support for both real-time and scheduled operations.

You can develop DES workflows in any programming language that can host an HTTP endpoint. Demo worker apps are available for both .NET and Java.

Create a project for workflows

Workflows are C# classes that implement the IDESWorkflow interface from the DMS.App package. This class contains the logic executed when a DES request is submitted.

dotnet new web

Add the DMS.App nuget package.

This package contains all dependencies required to develop a workflow that runs in DES.

Optionally add the DES.SQL if the workflow needs access to the database.

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net8.0</TargetFramework>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="DES.App" Version="3.6.0.61" />
    <PackageReference Include="DES.SQL" Version="3.6.0.61" />
  </ItemGroup>

</Project>

Create a class implementing IDESWorkflow

The RunAsync(...) function is called each time a DES request is submitted.

using DES.Core.Interfaces.Services;
using DES.Core.Models;

namespace DES.Demo.Workflow;

public class MyWorkflow : IDESWorkflow
{
    public Task<WorkflowResult> RunAsync(ExchangeRequest request, CancellationToken cancellationToken )
    {
        //workflow logic here

       //...
    }
}

Notice the ExchangeRequest argument. This contains parameters and settings configured in the Data Exchange.

Register Worker and Workflows

The app must call RegisterWorker(...) to register the app as a worker.

Workflows must be registered as a Dependency Injection container.

using DES.App;
using DES.App.Registration;
using DES.SQL.Logger;

var builder = WebApplication.CreateBuilder(args);

//Register worker
builder.RegisterWorker(options =>
{
    options.WorkerName = "DES.EWS.MyApp";
    //override any options here
});

//Optional DBLogger
builder.Services.AddDbLogger(builder.Configuration);

//Register workflows
builder.Services.AddScoped<IDESWorkflow, MyWorkflow>();

var app = builder.Build();

//Map worker endpoints 
app.MapWorkerEndpoints();

app.UseDbLogger();

app.Run();

Workflow classes can be used with Dependency Injection containers to reduce coupling between dependencies. For example, IConfiguration can be injected in the constructor when the workflow needs to read configuration files.

Worker Design

A Worker is an app in DES has that hosts workflows. This is the process that executes the logic.

In this case ews-myapp (exchange-worker-service for my app) is contains three workflow classes.

| ews-myapp | | --------------- | ------------- | -------------- | | | | Workflow | Workflow | Workflow | | A B C... |

ProcessRequest endpoint

The worker app will expose an HTTP endpoint to process requests.

POST /ProcessRequest
Content-Type: application/json

{
    "requestID": "guid id",
    "exchangeID": 123456,
    "exchangeName": "My workflow",
    "workflowClassName": "DMS.Workflows.MyWorkflow, DMS.Workflows",
    "exchangeParameters": {
        "param1": "param1value"
    }
}

The manager sends requests to the worker /ProcessRequest endpoint above.

Health endpoint

Additionally, the worker app will expose a health endpoint.

GET /healh

The health endpoint is used to report the worker's health and discover workflows capabilities.

Publish worker app

Once the app is ready, publish it using dotnet publish just like any other ASP.NET app .

dotnet publish -o ews-myapp

This is now ready to be hosted in IIS, Azure App Service, or any other hosting platform that DES has access to.