02_QuickStart

Quick Start Guide

This guide will help you get up and running with Facet in just a few steps.

1. Install the NuGet Package

dotnet add package Facet

For LINQ helpers:

dotnet add package Facet.Extensions

2. Define Your Source Model

public class Person
{
    public string Name { get; set; }
    public string Email { get; set; }
    public int Age { get; set; }
}

3. Create a Facet (DTO/Projection)

using Facet;

// Class
[Facet(typeof(Person), exclude: nameof(Person.Email))]
public partial class PersonDto { }

// Record (inferred from 'record' keyword)
[Facet(typeof(Person))]
public partial record PersonDto { }

// Struct (inferred from 'struct' keyword)
[Facet(typeof(Person))]
public partial struct PersonDto { }

4. Use the Generated Type

var person = new Person { Name = "Alice", Email = "a@b.com", Age = 30 };

var dto = new PersonDto(person); // Uses generated constructor

5. LINQ Integration

var query = dbContext.People.Select(PersonDto.Projection).ToList();

Or with Facet.Extensions:

using Facet.Extensions;

var dto = person.ToFacet<PersonDto>();

var dtos = personList.SelectFacets<PersonDto>();

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See the Attribute Reference and Extension Methods for more details.