I'm having some difficulties getting a custom action filter to work in ASP.NET Core 3.1 Web API. I've followed this SO, as well as the Microsoft docs, but it's not working. I've created a simple filter (note: I need Dependency Injection);
public class LogFilterAttribute : ActionFilterAttribute, IFilterMetadata
{
private readonly ILogger<LogFilterAttribute> _logger;
public LogFilterAttribute(ILogger<LogFilterAttribute> logger)
{
_logger = logger;
}
public override void OnActionExecuting(HttpActionContext actionContext)
{
_logger.LogWarning("test");
base.OnActionExecuting(actionContext);
}
}
Notes:
ActionFilterAttribute is from System.Web.Http.Filters namespace.
I implemented IFilterMetadata (which is just a marker interface) as this seems to be required by ServiceFilter and TypeFilter.
I'm registering this in ConfigureServices of Startup.cs as follows:
services.AddScoped<LogFilterAttribute>();
services.AddMvc().SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
and then applying this in my Web API controller as follows:
[ApiVersion("1.0")]
[ApiController]
[Route("v{version:apiVersion}/resources/{id}")]
public class ResourceController : ControllerBase
{
private readonly ILogger<ResourceController> _logger;
public ResourceController(ILogger<ResourceController> logger)
{
_logger = logger;
}
[HttpGet]
[ServiceFilter(typeof(LogFilterAttribute))]
public async Task<IActionResult> Get([FromRoute(Name = "id")] string id)
{
_logger.LogInformation($"{typeof(ResourceController)}.{nameof(Get)}");
return Ok();
}
}
I've tried with both ServiceFilter and TypeFilter, but to no avail - it just skips the break-point in filter and goes straight to my route logic. What am I doing wrong?
Try implementing IActionFilter in place of ActionFilterAttribute
In the end I solved the issue by implementing IAsyncActionFilter and inheriting from Attribute as follows:
public class LogFilterActionFilterAttribute : Attribute, IAsyncActionFilter
{
public LogFilterActionFilterAttribute(...)
{
...
}
public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
{
...
}
}
I also override TypeFilterAttribute as follows:
public class LogFilterAttribute : TypeFilterAttribute
{
public LogFilterAttribute (...) : base(typeof(LogFilterActionFilterAttribute))
{
Arguments = new object[] { ... };
}
}
So that I can decorate on controllers/routes as follows:
[ApiVersion("1.0")]
[ApiController]
[Route("v{version:apiVersion}/resources/{id}")]
public class ResourceController : ControllerBase
{
private readonly ILogger<ResourceController> _logger;
public ResourceController(ILogger<ResourceController> logger)
{
_logger = logger;
}
[HttpGet]
[LogFilter(...)]
public async Task<IActionResult> Get([FromRoute(Name = "id")] string id)
{
_logger.LogInformation($"{typeof(ResourceController)}.{nameof(Get)}");
return Ok();
}
}
In StartUp.cs, Add the filter in MVC pipeline.
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc(options =>
{
options.Filters.Add(typeof(LogFilterAttribute));
});
}
You need to use this on the controller/method as you're using a type filter, isn't the logger already scoped within the configuration? if so you need a type filter
[TypeFilter(typeof(LogFilterAttribute))]
For my use, I don't need to add IFilterMetadata
Related
I am working on an ASP.NET Core Web API application. My API will accept a country name as one of the input parameter from request body.
Due to nature of the application, we have country wise database with same schema. I have created DbContext for one of the databases and want to initialize the DbContext by the passing the connection string based on input request parameter value.
I have created factory method to return the needed database context based on the parameter passed to the factory method. However, the challenge I am facing is, while initializing the factory class as DI from controller, object of factory class is instantiated before the controller action is called. Hence, parameter value in factory method is empty.
How can I pass a parameter in runtime to initialize an object using dependency injection?
Here is the code...
public class Student
{
public int Id { get; set; }
public string Name { get; set; }
}
public class MyDBContext : DbContext
{
public MyDBContext(DbContextOptions<MyDBContext> options)
: base(options)
{
}
public virtual DbSet<Student> Students { get; set; }
}
public interface IDbContextFactory
{
public MyDBContext GetDbContext(string
connectionString);
}
public class DbContextFactory : IDbContextFactory
{
public MyDBContext GetDbContext(string connectionString)
{
MyDBContext context = null;
if (!string.IsNullOrWhiteSpace(connectionString))
{
DbContextOptionsBuilder<MyDBContext> _dbContextOptionsBuilder = new DbContextOptionsBuilder<MyDBContext>().UseSqlServer(connectionString);
context = new MyDBContext(_dbContextOptionsBuilder.Options);
}
return context;
}
}
public interface IRepository
{
Student GetData();
}
public class Repository : IRepository
{
private MyDBContext _context;
public Repository(IDbContextFactory dbContextFactory)
{
// Here I need connection string based on input parameter (country) from request to dynamically generate country specific connection string
string connectionString = string.Empty;
_context = dbContextFactory.GetDbContext(connectionString);
}
public Student GetData()
{
return _context.Students.FirstOrDefault();
}
}
public interface IServiceAgent
{
Student GetData();
}
public class ServiceAgent : IServiceAgent
{
IRepository _repository;
public ServiceAgent(IRepository repository)
{
_repository = repository;
}
public Student GetData()
{
return _repository.GetData();
}
}
[ApiController]
[Route("[controller]")]
public class HomeController : ControllerBase
{
private readonly IServiceAgent _serviceAgent;
public HomeController(IServiceAgent serviceAgent)
{
_serviceAgent = serviceAgent;
}
[HttpGet]
public Student Get(string country)
{
return _serviceAgent.GetData();
}
}
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.AddScoped<IServiceAgent, ServiceAgent>();
services.AddScoped<IRepository, Repository>();
services.AddScoped<IDbContextFactory, DbContextFactory>();
services.AddScoped<DetermineCountryFilter>();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
app.UseHttpsRedirection();
app.UseRouting();
app.UseAuthorization();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
I create a Web Api in asp.net core this the content of Api:
[Route("api/[controller]")]
public class BlogController : Controller
{
public IContext _context { get; set; }
public BlogController(IContext ctx)
{
_context = ctx;
}
[HttpGet]
[Route("api/Blog/GetAllBlog")]
public List<Blog> GetAllBlog()
{
return _context.Blogs.ToList();
}
}
as i know in ASp.net Core (WebApi Template) we don't need any configuration like registration Route, which we need in Asp.net Mvc 5.3 and older.
So when i try to call the GetAllBlog by browser or Postman, by this url http://localhost:14742/api/Blog/GetAllBlog , it gets me 404 error, what is problem?
You have already included the api/[controller] route at the top of the controller class so you don't need to include it again while defining route for accessing method.
In essence, change the Route to api/Blog/GetAllBlog to GetAllBlog. Your code should look like this:
[Route("api/[controller]")]
public class BlogController : Controller
{
public IContext _context { get; set; }
public BlogController(IContext ctx)
{
_context = ctx;
}
[HttpGet]
[Route("GetAllBlog")]
public List<Blog> GetAllBlog()
{
return _context.Blogs.ToList();
}
[HttpGet]
[Route("GetOldBlogs")]
public List<Blog> GetOldBlogs()
{
return _context.Blogs.Where(x => x.CreationDate <= DateTime.Now.AddYears(-2)).ToList();
}
}
You also need to have different route names for methods.
Hope this helps.
I created a ASP.net Web API controller like that:
public class UsersController : ApiController
{
//...
public void Put([FromBody]User_API user, long UpdateTicks)
{
user.UpdateTicks = UpdateTicks;
//...
}
}
The "user" parameter will be null if the client does not provide correct arguments. Can I make a global filter to check every parameter like this, and will return a 400 message if any error occurs.
Finally, I got the solution:
public class ModelValidateFilterAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(HttpActionContext actionContext)
{
if (actionContext.ActionArguments.Any(v => v.Value==null))
{
actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.BadRequest);
}
}
}
And...
//In Application_Start()
GlobalConfiguration.Configuration.Filters.Add(new ModelValidateFilterAttribute());
I'm trying to set a property on an System.Web.Http.ApiController to a value of a resolved IServerPackageRepository. The controller runs in a HttpSelfHostServer and the DependencyResolver has been set to AutofacWebApiDependencyResolver. Here is the code from the Autofac.Module.Load method
...
builder.RegisterType<ServerPackageRepository>()
.As<IServerPackageRepository>()
.SingleInstance()
.WithParameter("path", this.StoragePath);
builder.RegisterApiControllers(Assembly.GetExecutingAssembly())
.PropertiesAutowired();
The ApiController controller itself has a property of type
public IServerPackageRepository Repository { get; set; }
but is never resolved.
I am trying to do it this way because ApiController won't take nothing but default constructors. Any suggestions on how to do this the correct way using Autofac?
If the ApiController is only using the default constructor is sounds like the dependency resolver is not being called and may not be registered with Web API correctly. Here is a working example of self-hosting with constructor injection.
The dependency (in this case a simple logger):
public interface ILogger
{
void Log(string text);
}
public class Logger : ILogger
{
public void Log(string text)
{
Debug.WriteLine(text);
}
}
A simple controller with a dependency on the logger:
public class ValuesController : ApiController
{
readonly ILogger _logger;
public ValuesController(ILogger logger)
{
_logger = logger;
}
// GET api/values
public IEnumerable<string> Get()
{
_logger.Log("GET api/values");
return new string[] { "value1", "value2" };
}
}
The console application:
class Program
{
static void Main(string[] args)
{
var configuration = new HttpSelfHostConfiguration("http://localhost:8080");
configuration.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
var builder = new ContainerBuilder();
// Register API controllers using assembly scanning.
builder.RegisterApiControllers(Assembly.GetExecutingAssembly());
// Register API controller dependencies.
builder.Register<ILogger>(c => new Logger()).SingleInstance();
var container = builder.Build();
// Set the dependency resolver implementation.
var resolver = new AutofacWebApiDependencyResolver(container);
configuration.DependencyResolver = resolver;
// Open the HTTP server and listen for requests.
using (var server = new HttpSelfHostServer(configuration))
{
server.OpenAsync().Wait();
Console.WriteLine("Hosting at http://localhost:8080/{controller}");
Console.ReadLine();
}
}
}
Hit the controller action using:
http://localhost:8080/api/values
Please test this out and let me know if you have any problems.
Not sure if this is what you want but you can create your own base controller and inject the IServerPackageRepository into it.
public class MyApiController : ApiController {
public IServerPackageRepository ServerPackageRepository { get; set; }
public MyApiController(IServerPackageRepository serverPackageRepository) {
ServerPackageRepository = serverPackageRepository;
}
}
Then, use this as your base controller:
public class ProductsController : MyApiController {
public ProductsController(IServerPackageRepository serverPackageRepository)
: base(serverPackageRepository) {
}
public IEnumerable<Product> Get() {
ServerPackageRepository.DoWork();
//...
}
}
An alternative would be to directly wire your dependency to the property like so:
var repo = new ServerPackageRepository(path: this.StoragePath);
builder.RegisterInstance(repo)
.SingleInstance();
builder.RegisterApiControllers(Assembly.GetExecutingAssembly())
.WithProperty("Repository", repo)
.PropertiesAutowired();
I am new to MVC, repository concept and dependency injection.
My repository and DAL looks like
public interface IRepository<TEntity> where TEntity : class
{
List<TEntity> FetchAll();
IQueryable<TEntity> Query { get; }
void Add(TEntity entity);
void Delete(TEntity entity);
void Save();
}
public class Repository<T> : IRepository<T> where T : class
{
private readonly DataContext _db;
public Repository(DataContext db)
{
_db = db;
}
#region IRepository<T> Members
public IQueryable<T> Query
{
get { return _db.GetTable<T>(); }
}
public List<T> FetchAll()
{
return Query.ToList();
}
public void Add(T entity)
{
_db.GetTable<T>().InsertOnSubmit(entity);
}
public void Delete(T entity)
{
_db.GetTable<T>().DeleteOnSubmit(entity);
}
public void Save()
{
_db.SubmitChanges();
}
#endregion
}
In Global.asax file I have
private void RegisterDependencyResolver()
{
var kernel = new StandardKernel();
kernel.
Bind(typeof(IRepository<>)).
To(typeof(Repository<>))
.WithConstructorArgument("db", new DataContext(ConfigurationManager.ConnectionStrings["ConnectionString"].ToString()));
DependencyResolver.SetResolver(new NinjectDependencyResolver(kernel));
}
but when I am trying to access repository I get "Object reference not set to an instance of an object". Do I understand correctly how Repository and Injection should work?
public class AdminController : Controller
{
private readonly IRepository<User> _userRepository;
public ActionResult Index()
{
var a = _userRepository.FetchAll(); //I get exception here
return View();
}
}
You get nullref because you don't set _userRepository. Set it in the AdminControllers constructor and Niject will inject it happily:
public class AdminController : Controller
{
private readonly IRepository<User> _userRepository;
public AdminController(IRepository<User> userRepository)
{
_userRepository = userRepository;
}
//...
}
You can read here more about the injection patterns with Ninject and how injection works.
In the web config file
<appSettings>
<add key="RepoSetting" value="Solution.DAL.OrderRepository"/>
</appSettings>
In the ninject web common class
private static void RegisterServices(Ikernel Kernel)
{
//kernl.Bind<Irepo>().To<CustRepo>();
string name = WebConfigurationManager.AppSettings["RepoSetting"];
Type repoToInject = Assembly.GetExecutingAssembly().GetType(name);
kernel.Bind<ICustomerRepository>().To(repoToInject
}