Elsa Console Application

Elsa Workflows can be seamlessly integrated into console applications, offering a lightweight approach to run workflows. This guide will walk you through setting up Elsa in a console application and running a simple workflow.

Initial Setup

1. Create a New Console Application

Start by creating a new console application targeting .NET 8.0:

dotnet new console -n "ElsaConsole" -f net8.0

Navigate to your newly created project's root directory:

cd ElsaConsole

2. Install Elsa NuGet Package

To integrate Elsa into your console application, add the Elsa NuGet package:

dotnet add package Elsa

Configuring Elsa

1. Update Program.cs

Open Program.cs and replace its contents with the following code to set up Elsa:

using Elsa.Extensions;
using Elsa.Workflows.Activities;
using Elsa.Workflows.Contracts;
using Microsoft.Extensions.DependencyInjection;

// Setup service container.
var services = new ServiceCollection();

// Add Elsa services to the container.
services.AddElsa();

// Build the service container.
var serviceProvider = services.BuildServiceProvider();

This code sets up a service container and adds Elsa services to it. The serviceProvider will allow us to resolve Elsa services and run workflows.

2. Define and Run a Workflow

To test Elsa in action, append the following code to Program.cs:

// Define a simple workflow that writes a message to the console.
var workflow = new WriteLine("Hello world!");

// Resolve a workflow runner to execute the workflow.
var workflowRunner = serviceProvider.GetRequiredService<IWorkflowRunner>();

// Execute the workflow.
await workflowRunner.RunAsync(workflow);

Running the program should display:

Hello world!

3. Experimenting with Workflows

Elsa's flexibility allows you to define more complex workflows. For instance, replace the workflow variable with the following sequence of activities:

var workflow = new Sequence
{
    Activities =
    {
        new WriteLine("Hello World!"), 
        new WriteLine("Goodbye cruel world...")
    }
};

Executing the program now should produce:

Hello World!
Goodbye cruel world...

This example demonstrates how you can chain multiple activities in a sequence. As you delve deeper into Elsa, you'll discover a plethora of activities and configurations to tailor workflows to your needs.