markthiessen/pipr

A simple chain of responsibility pipeline for .NET

Pipr

A simple chain of responsibility pipeline for .NET

Installing Pipr

You should install Pipr with NuGet:

Install-Package Pipr

Or via the .NET Core command line interface:

dotnet add package Pipr

Either commands, from Package Manager Console or .NET Core CLI, will download and install Pipr and all required dependencies.

Usage

Simple

First, create some steps that implement IStep<Tin, Tout>.

public class ToStringStep : IStep<int, string>
{
    public string Execute(int input, PipelineContext context)
    {
        return input.ToString();
    }
}

public class DoublerStep : IStep<string, string>
{
    public string Execute(string input, PipelineContext context)
    {
        return input + input;
    }
}

Then configure a pipeline by adding your steps

var pipeline = new PipelineBuilder()
            .AddStep(new ToStringStep())
            .AddStep(new DoublerStep())
            .Build();

var result = pipeline.Execute(12);

// result.Value in this example should be "1212"

The in/out of the pipeline can be inferred by the type system as you add steps.

Aborting

Pipeline steps can cancel and abort further processing by calling context.Cancel():

For example

public class CancellingStep : IStep<string, string>
{
    public string Execute(string input, PipelineContext context)
    {
        context.Cancel();
        return "a value";
    }
}

If a step cancels further processing, no following steps will run, and the pipeline return value will be the default value for the return type.