05_Extensions.md

Extension Methods (LINQ, EF Core, etc.)

Facet.Extensions provides a set of provider-agnostic extension methods for mapping and projecting between your domain entities and generated facet types. For async EF Core support, see the separate Facet.Extensions.EFCore package.

Key Methods (Facet.Extensions)

Method	Description
ToFacet<TSource, TTarget>()	Map a single object using the generated constructor.
SelectFacets<TSource, TTarget>()	Map an IEnumerable<TSource> to IEnumerable<TTarget>.
SelectFacet<TSource, TTarget>()	Project an IQueryable<TSource> to IQueryable<TTarget>.

Key Methods (Facet.Extensions.EFCore)

Method	Description
ToFacetsAsync<TSource, TTarget>()	Async projection to List<TTarget> (EF Core).
FirstFacetAsync<TSource, TTarget>()	Async projection to first or default (EF Core).
SingleFacetAsync<TSource, TTarget>()	Async projection to single (EF Core).

Usage Examples

Extensions

dotnet add package Facet.Extensions

using Facet.Extensions;

// provider-agnostic
// Single object
var dto = person.ToFacet<Person, PersonDto>();

// Enumerable
var dtos = people.SelectFacets<Person, PersonDto>();

EF Core Extensions

dotnet add package Facet.Extensions.EFCore

// IQueryable (LINQ/EF Core)

using Facet.Extensions.EFCore; 

var query = dbContext.People.SelectFacet<Person, PersonDto>();

// Async (EF Core)
var dtosAsync = await dbContext.People.ToFacetsAsync<Person, PersonDto>();
var firstDto = await dbContext.People.FirstFacetAsync<Person, PersonDto>();
var singleDto = await dbContext.People.SingleFacetAsync<Person, PersonDto>();

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See Quick Start for setup and Facet.Extensions.EFCore for async EF Core support.