Petl

A Programmable ETL (Extract, Transform, Load) Library designed around using a fluent interface to transform data from inputs to outputs.

Features

• Fluent Interface: Easy-to-use builder pattern for creating transformation pipelines
• Property Transformations: Simple type-to-type data copying between properties
• Custom Transformations: Support for custom transformation logic with callback handlers
• Pipeline Steps: Organize transformations into logical steps
• Type Safety: Full generic type support for compile-time safety

Quick Start

using Petl;

// Define your input and output models
public class InputModel
{
    public string SourceProperty { get; set; } = string.Empty;
    public int SomeProperty { get; set; }
}

public class OutputModel
{
    public string TargetProperty { get; set; } = string.Empty;
    public string SomeProperty { get; set; } = string.Empty;
}

// Create a transformation pipeline
var builder = new PipelineBuilder<InputModel, OutputModel>();

builder
    .WithStep("Simple Transform")
        .Property(
            x => x.SourceProperty,
            y => y.TargetProperty
        )
        .Transform((source, target) => {
            target.SomeProperty = source.SomeProperty.ToString();
        });

var pipeline = builder.Build();

// Execute the transformation
var myInput = new InputModel
{
    SourceProperty = "Hello World",
    SomeProperty = 42
};
var myOutput = new OutputModel();

pipeline.Exec(myInput, myOutput);

API Reference

PipelineBuilder<TSource, TTarget>

The main entry point for creating transformation pipelines.

• WithStep(string stepName): Creates a new transformation step
• Build(): Builds the pipeline

TransformationStep<TSource, TTarget>

Represents a single step in the transformation pipeline.

• Property(Expression<Func<TSource, object?>> sourceProperty, Expression<Func<TTarget, object?>> targetProperty): Maps a source property to a target property
• Transform(Action<TSource, TTarget> transformAction): Applies custom transformation logic

Pipeline<TSource, TTarget>

The executable pipeline that performs the transformations.

• Exec(TSource source, TTarget target): Executes the transformation pipeline
• StepCount: Gets the number of transformation steps
• StepNames: Gets the names of all transformation steps

License

This project is part of the Petl ETL library.