Resource Repositories

If you want to use a data access technology other than Entity Framework Core, you can create an implementation of IResourceRepository<TResource, TId>. If you only need minor changes you can override the methods defined in EntityFrameworkCoreRepository<TResource, TId>.

// Program.cs
builder.Services.AddScoped<IResourceRepository<Article, long>, ArticleRepository>();
builder.Services.AddScoped<IResourceReadRepository<Article, long>, ArticleRepository>();
builder.Services.AddScoped<IResourceWriteRepository<Article, long>, ArticleRepository>();

In v4.0 we introduced an extension method that you can use to register a resource repository on all of its JsonApiDotNetCore interfaces. This is helpful when you implement (a subset of) the resource interfaces and want to register them all in one go.

// Program.cs
builder.Services.AddResourceRepository<ArticleRepository>();

Tip

If you're using auto-discovery, then resource services, repositories and resource definitions will be automatically registered for you.

A sample implementation that performs authorization might look like this.

All of the methods in EntityFrameworkCoreRepository will use the GetAll() method to get the DbSet<TResource>, so this is a good method to apply filters such as user or tenant authorization.

public class ArticleRepository : EntityFrameworkCoreRepository<Article, long>
{
    private readonly IAuthenticationService _authenticationService;

    public ArticleRepository(IAuthenticationService authenticationService,
        ITargetedFields targetedFields, IDbContextResolver dbContextResolver,
        IResourceGraph resourceGraph, IResourceFactory resourceFactory,
        IEnumerable<IQueryConstraintProvider> constraintProviders,
        ILoggerFactory loggerFactory,
        IResourceDefinitionAccessor resourceDefinitionAccessor)
        : base(targetedFields, dbContextResolver, resourceGraph, resourceFactory,
            constraintProviders, loggerFactory, resourceDefinitionAccessor)
    {
        _authenticationService = authenticationService;
    }

    public override IQueryable<Article> GetAll(CancellationToken cancellationToken)
    {
        return base.GetAll(cancellationToken)
            .Where(article => article.UserId == _authenticationService.UserId);
    }
}

Multiple DbContexts

If you need to use multiple Entity Framework Core DbContexts, first create a repository for each context and inject its typed resolver. This example shows a single DbContextARepository for all entities that are members of DbContextA.

public class DbContextARepository<TResource, TId>
    : EntityFrameworkCoreRepository<TResource, TId>
    where TResource : class, IIdentifiable<TId>
{
    public DbContextARepository(ITargetedFields targetedFields,
        DbContextResolver<DbContextA> dbContextResolver,
    //  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
        IResourceGraph resourceGraph, IResourceFactory resourceFactory,
        IEnumerable<IQueryConstraintProvider> constraintProviders,
        ILoggerFactory loggerFactory, IResourceDefinitionAccessor resourceDefinitionAccessor)
        : base(targetedFields, dbContextResolver, resourceGraph, resourceFactory,
            constraintProviders, loggerFactory, resourceDefinitionAccessor)
    {
    }
}

Then register the added types and use the non-generic overload of AddJsonApi to add their resources to the graph.

// Program.cs
builder.Services.AddDbContext<DbContextA>(options => options.UseSqlite("Data Source=A.db"));
builder.Services.AddDbContext<DbContextB>(options => options.UseSqlite("Data Source=B.db"));

builder.Services.AddJsonApi(dbContextTypes: new[] { typeof(DbContextA), typeof(DbContextB) });

builder.Services.AddScoped<IResourceRepository<ResourceA>, DbContextARepository<ResourceA>>();
builder.Services.AddScoped<IResourceRepository<ResourceB>, DbContextBRepository<ResourceB>>();