Patch does not update the data

Patch does not update the data

We are building an API in AspNetCore (without a mapping for the entities). While using the JsonApiController, the Get, Post en Delete work fine. However, the Patch does not work.

I have override the PatchAsync, and the application get into that breakpoint, but the entity remains empty and the AttributesToUpdate remains an empty list.

I seems as if this code should work (even without the overriding method in the controller). What am I missing, or what could I test?

------ see (parts of) the code below. ------

Key	Value
Type	PATCH
URL	http://localhost:62596/patchtable/2
Content-Type	application/vnd.api+json
Body	{“data”: {“type”: “patchtable”,“id”: 2,“attributes”: {“text”: “A new value”}}}

The code inside the PatchtableController.cs. In comments I’ve added some of the findings I’ve made when trying to debug what was going on.

    public class PatchtableController : JsonApiController<Patchtable>
    {
        private IJsonApiContext _jsonApiContext;

        public PatchtableController(
            IJsonApiContext jsonApiContext, 
            IResourceService<Patchtable, int> resourceService) :
            base(jsonApiContext, resourceService)
        {
            _jsonApiContext = jsonApiContext;
        }

        [HttpPatch("{id}")]
        public override async Task<IActionResult> PatchAsync(int id, [FromBody] Patchtable entity)
        {
            //  _jsonApiContext.AttributesToUpdate.Count -> 0;
            //  Patchtable entity -> null

            return await base.PatchAsync(id, entity);
        }
    }

The test-model is just a simple without any relations. See the Patchtable .cs, the PatchtableTypeConfiguration below and part of our ApplicationDbContext.cs below.

    public class Patchtable : Identifiable
    {
        [Attr("text")]
        [Required]
        public string Text { get; set; }
    }

    public class PatchtableTypeConfiguration : IEntityTypeConfiguration<Patchtable>
    {
        public void Configure(EntityTypeBuilder<Patchtable> builder)
        {
            builder.HasKey(x => x.Id);

            builder.Property(x => x.Text)
                .IsRequired();
        }
    }

    public class ApplicationDbContext : DbContext
    {
        public ApplicationDbContext(DbContextOptions options) : base(options) { }

        public DbSet<...> ...{ get; set; }
        public DbSet<Patchtable> Patchtables { get; set; }

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.ApplyConfiguration(new ...TypeConfiguration());
            modelBuilder.ApplyConfiguration(new PatchtableTypeConfiguration());
        }
    }

See the Startup.cs below. I’ve tested the application with adding the option options.EnableOperations = true, without result.

    public void ConfigureServices(IServiceCollection services)
    {
        string connection = Configuration["ConnectionStrings:DefaultConnection"];
        string assemblyName = Assembly.GetAssembly(typeof(ApplicationDbContext)).FullName;
        services.AddDbContext<ApplicationDbContext>(options =>
            options.UseSqlServer(
                connection,
                sqlServerOption => sqlServerOption.MigrationsAssembly(assemblyName)));
        services.AddJsonApi<ApplicationDbContext>();
        services.AddOpenApiDocument(settings =>
            settings.SchemaType = SchemaType.OpenApi3);
        services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_2_2);
    }

…

Environment

• JsonApiDotNetCore version: 3.1.0
• Microsoft.AspNetCore.App version: 2.2.0
• Microsoft.EntityFrameworkCore.SqlServer version: 2.2.4
• Microsoft.NETCore.App version: 2.2.0

[incomudro]

Thanks for the feedback, it helped me in the right direction 😃

Although the name of controller seems to have little consequences, apart from the URL.

I’ve updated my test-project and will leave it there for a while. Feel free to pick anything from it should you wish to add another example to your list of example-projects. In the readme I’ve added two lessons-learned, the things we probably did wrong while trying to figure out why Patch did not work. https://github.com/incomudro/ApiTestProject

Lesson 1: Case-sensitivity For PATCH, the attribute is case-sensitive and should be the same as defined in the model. As the attribute is not case-sensitive for POST, this mistake was probably overlooked once or twice.

Lesson 2: Type The type defined in the PATCH, should be the same as the name for the DbSet<T>. Thus when the DbSet<Fruit> is ‘Fruits’, the type provided in the body of the PATCH should be ‘fruits’ as well.

Know that the type is not case-sensitive and both "type": "fruits" and "type": "Fruits" will work.

[milosloub]

@incomudro Hi, be carefull with your naming convention - your Context use Patchables and your type is “patchable”. The problem with this line services.AddJsonApi<ApplicationDbContext>(); is, that your application must use same convention in controller layer as you use in your ApplicationDbContext. And there is another hidden convention with this - your controller name defines “type” (BlogController => type=“blog”, BlogsController => type=“blogs”)

First approach to fix- pluralize

1. Change your PatchtableController -> PatchtablesController
2. Change your url to: http://localhost:62596/patchtables/2
3. Change your type in body from “patchable” to “patchables”

Second approach to fix - singularize

1. Change your DbSet<Patchtable> Patchtables -> DbSet<Patchtable> Patchtable