Here's the code:
controller:
//POST api/substances
[HttpPost]
[ServiceFilter(typeof(ValidateNameExistsAttribute<Substance>))]
public ActionResult<SubstanceReadDto> CreateSubstance([FromBody]SubstanceSaveDto dto)
{
var substanceModel = _mapper.Map<Substance>(dto);
_repository.CreateSubstance(substanceModel);
_repository.SaveChanges();
var substanceReadDto = _mapper.Map<SubstanceReadDto>(substanceModel);
return CreatedAtRoute(nameof(GetSubstanceById), new {substanceReadDto.Id}, substanceReadDto);
}
Filter
using System.Linq;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Filters;
using Pharmacy.Data;
using Pharmacy.Models;
namespace Pharmacy.Filters
{
public class ValidateNameExistsAttribute<T> : IActionFilter where T : class, INameEntity
{
private readonly PharmacyContext _context;
public ValidateNameExistsAttribute(PharmacyContext context)
{
_context = context;
}
public void OnActionExecuted(ActionExecutedContext context)
{
}
public void OnActionExecuting(ActionExecutingContext context)
{
if (context.ActionArguments.ContainsKey("dto"))
{
var entity = new object();
var dto = context.ActionArguments["dto"] as INameDto;
if (dto == null)
{
context.Result = new BadRequestObjectResult("Invalid request body");
return;
}
if (context.ActionArguments.ContainsKey("id"))
{
var id = (int) context.ActionArguments["id"];
entity = _context.Set<T>().SingleOrDefault(it => String.Equals(it.Name, dto.Name, StringComparison.OrdinalIgnoreCase) && it.Id != id);
}
else
{
entity = _context.Set<T>().SingleOrDefault(it => String.Equals(it.Name, dto.Name, StringComparison.OrdinalIgnoreCase));
}
if (entity != null)
{
var problemDetails = new ProblemDetails
{
Title = "Duplicate resource",
Detail = $"A record with provided name {dto.Name} already exists",
Instance = context.HttpContext.Request.Path
};
context.Result = new ObjectResult(problemDetails)
{
StatusCode = 409
};
}
}
}
}
}
and here's the error message: What's wrong with code?
{
"type": "https://tools.ietf.org/html/rfc7231#section-6.6.1",
"title": "The LINQ expression 'DbSet\r\n .Where(s => string.Equals(\r\n a: s.Name, \r\n b: __dto_Name_0, \r\n comparisonType: OrdinalIgnoreCase))' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to either AsEnumerable(), AsAsyncEnumerable(), ToList(), or ToListAsync(). See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.",
"status": 500,
"detail": " at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.g__CheckTranslated|8_0(ShapedQueryExpression translated, <>c__DisplayClass8_0& )\r\n at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)\r\n at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)\r\n at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)\r\n at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)\r\n at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)\r\n at Microsoft.EntityFrameworkCore.Storage.Database.CompileQuery[TResult](Expression query, Boolean async)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.CompileQueryCore[TResult](IDatabase database, Expression query, IModel model, Boolean async)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass9_01.<Execute>b__0()\r\n at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQueryCore[TFunc](Object cacheKey, Func1 compiler)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func1 compiler)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.Execute[TResult](Expression query)\r\n at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.Execute[TResult](Expression expression)\r\n at System.Linq.Queryable.SingleOrDefault[TSource](IQueryable1 source, Expression1 predicate)\r\n at Pharmacy.Filters.ValidateNameExistsAttribute1.OnActionExecuting(ActionExecutingContext context) in D:\.Pharmac Project\pharmac\Filters\ValidateNameExistsAttribute.cs:line 43\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeNextActionFilterAsync()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()\r\n--- End of stack trace from previous location where exception was thrown ---\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\r\n at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)\r\n at Microsoft.AspNetCore.Routing.EndpointMiddleware.g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)\r\n at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)\r\n at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)\r\n at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)\r\n at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)\r\n at Serilog.AspNetCore.RequestLoggingMiddleware.Invoke(HttpContext httpContext)\r\n at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)",
"traceId": "|9542c43b-43548354a97cc054."
}
Related
I currently have a problem with EF6 and Fluent API. When inserting into database where model have one to many relationship, I'm getting this error. I've checked some related topics, but I want to keep autoincrement. Model without one to many relationship works perfectly.
Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while saving the entity changes. See the inner exception for details.
---> Microsoft.Data.SqlClient.SqlException (0x80131904): Cannot insert explicit value for identity column in table 'Roles' when IDENTITY_INSERT is set to OFF.
at Microsoft.Data.SqlClient.SqlCommand.<>c.<ExecuteDbDataReaderAsync>b__188_0(Task`1 result)
at System.Threading.Tasks.ContinuationResultTaskFromResultTask`2.InnerInvoke()
at System.Threading.Tasks.Task.<>c.<.cctor>b__272_0(Object obj)
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
--- End of stack trace from previous location ---
at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread)
--- End of stack trace from previous location ---
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
ClientConnectionId:501a6880-e298-43d5-be69-fcbebacdb15e
Error Number:544,State:1,Class:16
--- End of inner exception stack trace ---
at Microsoft.EntityFrameworkCore.Update.ReaderModificationCommandBatch.ExecuteAsync(IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Update.Internal.BatchExecutor.ExecuteAsync(IEnumerable`1 commandBatches, IRelationalConnection connection, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(IList`1 entriesToSave, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.ChangeTracking.Internal.StateManager.SaveChangesAsync(StateManager stateManager, Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.DbContext.SaveChangesAsync(Boolean acceptAllChangesOnSuccess, CancellationToken cancellationToken)
at WorkIT_Backend.Services.UserService.Create(String username, String password, String role) in C:\Users\Ondřej\Desktop\škola\2022 PRF\WS\OPR3\WorkIT_Backend\WorkIT_Backend\WorkIT_Backend\Services\UserService.cs:line 54
at WorkIT_Backend.Controllers.UsersController.CreateUser(UserDto user) in C:\Users\Ondřej\Desktop\škola\2022 PRF\WS\OPR3\WorkIT_Backend\WorkIT_Backend\WorkIT_Backend\Controllers\UsersController.cs:line 57
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|20_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)
at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
Model classes
public sealed class Role
{
public long RoleId { get; set; }
public string? Name { get; set; }
public ICollection<User> Users { get; set; }
public Role()
{
Users = new HashSet<User>();
}
}
public class User
{
public long UserId { get; set; }
public string? UserName { get; set; }
public string? PasswordHash { get; set; }
public long RoleId { get; set; }
public virtual Role Role { get; set; }
public User()
{
}
}
OnModelCreating in dbcontext
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
modelBuilder.Entity<Role>(entity =>
{
entity.HasKey(q => q.RoleId);
entity.Property(q => q.RoleId)
.ValueGeneratedOnAdd();
entity.Property(q => q.Name)
.IsRequired();
entity.HasIndex(q => q.Name)
.IsUnique();
});
modelBuilder.Entity<User>(entity =>
{
entity.HasKey(q => q.UserId);
entity.Property(q => q.UserId)
.ValueGeneratedOnAdd();
entity.Property(q => q.UserName)
.IsRequired();
entity.Property(q => q.PasswordHash)
.IsRequired();
entity.HasOne(u => u.Role)
.WithMany(r => r.Users)
.HasForeignKey(u => u.RoleId)
.OnDelete(DeleteBehavior.ClientSetNull);
});
}
Method in service which is adding the user
public async Task<User> Create(string username, string password, string role)
{
EnsureNotNull(username, nameof(username));
EnsureNotNull(password, nameof(password));
EnsureNotNull(role, nameof(role));
username = username.ToLower();
if (_context.Users.Any(q => q.UserName == username))
throw CreateException($"User {username} already exists.", null);
var hash = _securityService.HashPassword(password);
var userRole = await _roleService.GetRole(role);
var ret = new User {UserName = username, PasswordHash = hash, Role = userRole};
_context.Users.Add(ret);
await _context.SaveChangesAsync();
return ret;
}
This method for adding roles works perfectly
public class RoleService
{
private readonly WorkItDbContext _context;
private readonly SecurityService _securityService;
public RoleService(WorkItDbContext context, SecurityService securityService)
{
_context = context;
_securityService = securityService;
}
public async Task<Role> Create(string name)
{
EnsureNotNull(name, nameof(name));
name = name.ToLower();
if (_context.Roles.Any(q => q.Name == name))
throw CreateException($"Role {name} already exists.", null);
var ret = new Role {Name = name};
_context.Add(ret);
await _context.SaveChangesAsync();
return ret;
}
public async Task<List<Role>> GetRoles()
{
var roles = await _context.Roles.ToListAsync();
return roles;
}
public async Task<Role> GetRole(string name)
{
var role = await _context.Roles.FirstAsync(q => q.Name == name) ??
throw CreateException($"Role {name} does not exist.");
return role;
}
}
Program.cs
var builder = WebApplication.CreateBuilder(args);
builder.Services.AddSingleton<IConfiguration>(builder.Configuration);
SecurityService securityService = new(builder.Configuration);
builder.Services.AddTransient<WorkItDbContext>();
builder.Services.AddSingleton<SecurityService>();
builder.Services.AddTransient<UserService>();
builder.Services.AddTransient<RoleService>();
I've different combination of dbcontext methods. I tried auto increment through anotation - identity. I've checked SQL server and autoincrement is alright.
Change
builder.Services.AddTransient<WorkItDbContext>();
to
builder.Services.AddDbContext<WorkItDbContext>();
and then your UserService and RoleService will share a WorkItDbContext, because it will be added as a Scoped service. See DbContext in dependency injection for ASP.NET Core
I'm getting myself familiar with Automapper. I'm using this project template as a starting point and always run into problem with Automapper.
public class GetMealsToBeServedListDto : IMapFrom<SubOrder>
{
public int SubOrderId { get; set; }
public int SubOrderNumber { get; set; }
public ICollection<GetMealsToBeServedListOrderedMealDto>? GetMealsToBeServedListOrderedMealDtos { get; set; }
public void Mapping(Profile profile)
{
profile.CreateMap<SubOrder, GetMealsToBeServedListDto>()
.ForMember(d => d.SubOrderId, opt => opt.MapFrom(s => s.Id))
.ForMember(d => d.SubOrderNumber, opt => opt.MapFrom(s => s.SubOrderNumber))
// This is the problematic where statement.
.ForMember(d => d.GetMealsToBeServedListOrderedMealDtos, opt => opt.MapFrom(s => s.OrderedMeals != null ? s.OrderedMeals.Where(p => p.CompletedOn.HasValue && p.CompletedOn != DateTime.MinValue) :
null));
}
}
public class GetMealsToBeServedListOrderedMealDto : IMapFrom<OrderedMeal>
{
public int Quantity { get; set; }
public DateTime CompletedOn { get; set; }
public void Mapping(Profile profile)
{
profile.CreateMap<OrderedMeal, GetMealsToBeServedListOrderedMealDto>()
.ForMember(d => d.Quantity, opt => opt.MapFrom(s => s.Quantity))
.ForMember(d => d.CompletedOn, opt => opt.MapFrom(s => s.CompletedOn));
}
}
The following is my query.
return new GetMealsToBeServedListVm
{
GetMealsToBeServedListDtos = await _context.SubOrders
.AsNoTracking()
.Where(x => x.OrderedMeals != null && x.OrderedMeals.Any(p => p.CompletedOn.HasValue && p.CompletedOn != DateTime.MinValue))
.ProjectTo<GetMealsToBeServedListDto>(_mapper.ConfigurationProvider)
.OrderByDescending(t => t.SubOrderNumber)
.ToListAsync(cancellationToken)
};
When I try to execute the query, I receive following error. I spent hours on trying to solve the following issue in vain. I tried different methods like Automapper Condition, PreCondition, etc... none did work so far. could anyone please shad a right here?
> System.InvalidOperationException: The LINQ expression 'dtoOrderedMeal => new GetMealsToBeServedListOrderedMealDto{
CompletedOn = dtoOrderedMeal.CompletedOn ?? 01/01/0001 00:00:00,
Quantity = dtoOrderedMeal.Quantity
}
' could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'. See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.
at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.VisitLambda[T](Expression`1 lambdaExpression)
at System.Linq.Expressions.Expression`1.Accept(ExpressionVisitor visitor)
at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
at Microsoft.EntityFrameworkCore.Query.RelationalSqlTranslatingExpressionVisitor.TranslateInternal(Expression expression)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMemberAssignment(MemberAssignment memberAssignment)
at System.Linq.Expressions.ExpressionVisitor.VisitMemberBinding(MemberBinding node)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.VisitMemberInit(MemberInitExpression memberInitExpression)
at System.Linq.Expressions.MemberInitExpression.Accept(ExpressionVisitor visitor)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Visit(Expression expression)
at Microsoft.EntityFrameworkCore.Query.Internal.RelationalProjectionBindingExpressionVisitor.Translate(SelectExpression selectExpression, Expression expression)
at Microsoft.EntityFrameworkCore.Query.RelationalQueryableMethodTranslatingExpressionVisitor.TranslateSelect(ShapedQueryExpression source, LambdaExpression selector)
at Microsoft.EntityFrameworkCore.Query.QueryableMethodTranslatingExpressionVisitor.VisitMethodCall(MethodCallExpression methodCallExpression)
at System.Linq.Expressions.MethodCallExpression.Accept(ExpressionVisitor visitor)
at System.Linq.Expressions.ExpressionVisitor.Visit(Expression node)
at Microsoft.EntityFrameworkCore.Query.QueryCompilationContext.CreateQueryExecutor[TResult](Expression query)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.<>c__DisplayClass12_0`1.<ExecuteAsync>b__0()
at Microsoft.EntityFrameworkCore.Query.Internal.CompiledQueryCache.GetOrAddQuery[TResult](Object cacheKey, Func`1 compiler)
at Microsoft.EntityFrameworkCore.Query.Internal.QueryCompiler.ExecuteAsync[TResult](Expression query, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryProvider.ExecuteAsync[TResult](Expression expression, CancellationToken cancellationToken)
at Microsoft.EntityFrameworkCore.Query.Internal.EntityQueryable`1.GetAsyncEnumerator(CancellationToken cancellationToken)
at System.Runtime.CompilerServices.ConfiguredCancelableAsyncEnumerable`1.GetAsyncEnumerator()
at Microsoft.EntityFrameworkCore.EntityFrameworkQueryableExtensions.ToListAsync[TSource](IQueryable`1 source, CancellationToken cancellationToken)
at test.Application.Orders.Queries.GetMealsToBeServedList.GetOrderPageListQueryHander.Handle(GetMealsToBeServedListQuery request, CancellationToken cancellationToken) in E:\Dev\test\backend\src\Application\Orders\Queries\GetMealsToBeServedList\GetMealsToBeServedListQuery.cs:line 44
at test.Application.Common.Behaviours.PerformanceBehaviour`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next) in E:\Dev\test\backend\src\Application\Common\Behaviours\PerformanceBehaviour.cs:line 31
at test.Application.Common.Behaviours.ValidationBehaviour`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next) in E:\Dev\test\backend\src\Application\Common\Behaviours\ValidationBehaviour.cs:line 35
at test.Application.Common.Behaviours.AuthorizationBehaviour`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next) in E:\Dev\test\backend\src\Application\Common\Behaviours\AuthorizationBehaviour.cs:line 78
at test.Application.Common.Behaviours.UnhandledExceptionBehaviour`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next) in E:\Dev\test\backend\src\Application\Common\Behaviours\UnhandledExceptionBehaviour.cs:line 19
at MediatR.Pipeline.RequestExceptionProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
at MediatR.Pipeline.RequestExceptionProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
at MediatR.Pipeline.RequestExceptionActionProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
at MediatR.Pipeline.RequestExceptionActionProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
at MediatR.Pipeline.RequestPostProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
at MediatR.Pipeline.RequestPreProcessorBehavior`2.Handle(TRequest request, CancellationToken cancellationToken, RequestHandlerDelegate`1 next)
at test.WebUI.Controllers.OrderController.MealToBeServedList(GetMealsToBeServedListQuery query) in E:\Dev\test\backend\src\WebUI\Controllers\OrderController.cs:line 59
at lambda_method253(Closure , Object )
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.AwaitableObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextExceptionFilterAsync>g__Awaited|26_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ExceptionContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
See the AutoMapper documentation for Queryable Extensions.
It states that ProjectTo must be the last call in the chain, any filtering and sorting must be done on the entities first, before the projection to DTOs. If not you'll get the exception you are received because Linq to SQL does not know how to deal with your DTO type.
Swapping the call to OrderByDescending with ProjectTo should fix the issue, but you'll need to rewrite your lambda inside OrderByDescending to use the entity property instead of the DTO.
I ended up moving the filter away from Automapper. But I still would like to know what the best a way forward on this is.
return new GetMealsToBeServedListVm
{
GetMealsToBeServedListDtos = await _context.SubOrders
.AsNoTracking()
.Where(x => x.OrderedMeals != null && x.OrderedMeals.Any(p => p.CompletedOn.HasValue && p.CompletedOn != DateTime.MinValue))
.Select(s => new SubOrder
{
Id = s.Id,
SubOrderNumber = s.SubOrderNumber,
OrderedMeals = s.OrderedMeals.Where(x => x.CompletedOn.HasValue && x.CompletedOn != DateTime.MinValue).ToList(),
}
).ProjectTo<GetMealsToBeServedListDto>(_mapper.ConfigurationProvider)
.ToListAsync(cancellationToken)
};
I am coding a dynamic website, everything works but I noticed an error in the terminal.
Error:
fail: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware[1]
An unhandled exception has occurred while executing the request.
Microsoft.CSharp.RuntimeBinder.RuntimeBinderException: Cannot perform runtime binding on a null reference
at CallSite.Target(Closure , CallSite , Object )
at AspNetCore.Views_Content_CategoryContent.ExecuteAsync() in C:\Users\lenovo\Desktop\Projeler\Wutemp\Views\Content\CategoryContent.cshtml:line 2
at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, Boolean invokeViewStarts)
at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, String contentType, Nullable`1 statusCode)
at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, String contentType, Nullable`1 statusCode)
at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ActionContext actionContext, IView view, ViewDataDictionary viewData, ITempDataDictionary tempData, String contentType, Nullable`1 statusCode)
at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewResultExecutor.ExecuteAsync(ActionContext context, ViewResult result)
at Microsoft.AspNetCore.Mvc.ViewResult.ExecuteResultAsync(ActionContext context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|29_0[TFilter,TFilterAsync](ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
Controller (Edit: I accidentally deleted the ViewBag part):
[Route("Content/{url}/{id}")]
public IActionResult Index(int id)
{
var content = repoContents.TGet(id);
//If content has a category, go to CategoryContent
if(content.ContentCategory != null && content.ContentCategory != 0){
return RedirectToAction("CategoryContent", new
{
category = repoContentCategories.TGet((int)content.ContentCategory).Title,
url = content.URL,
id = content.ID
});
}
else{
ViewBag.Content = content;
return View();
}
}
What is the problem, and how can I solve it?
I solved the problem.
I used model instead of ViewBag mentioned in comments it didn't work I kept getting the same error
I think the problem is due to the similarity of the route parts of the 2 Views.
Index:
[Route("Content/{url}/{id}")]
public IActionResult Index(int id)
{
var content = repoContents.TGet(id);
//If content has a category, go to CategoryContent
if(content.ContentCategory != null && content.ContentCategory != 0){
return RedirectToAction("CategoryContent", new
{
category = repoContentCategories.TGet((int)content.ContentCategory).Title,
url = content.URL,
id = content.ID
});
}
else{
ViewBag.Content = content;
return View();
}
}
CategoryContent:
[Route("Content/{category}/{url}/{id}")]
public IActionResult CategoryContent(int id)
{
ViewBag.Content = repoContents.TGet(id);
return View();
}
I solved the problem by changing the Route part of the ContentCategory page
[Route("Content/{category}/{url}/{id}")]
|
V
[Route("Category-Content/{category}/{url}/{id}")]
I am new to blazor, and ef core.
I need a parameter passed into a function on my DbContext, I have created a service that has an 'int' field, but I am struggling to inject this into the context... I'm not sure what I need to do here, everything I've tried still results in an error. Some help would be great...
I'm trying to inject the "_cookieRepo" into the code, but I cannot pass an additional parameter into the constructor, when i do i get the "Cannot resolve scoped services" error.
Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.AddRazorPages();
services.AddServerSideBlazor();
services.AddDbContextFactory<OlqtContext>(options =>
options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection"))
.LogTo(log => Debug.WriteLine(log),
new[] { DbLoggerCategory.Database.Command.Name },
Microsoft.Extensions.Logging.LogLevel.Information)
.EnableSensitiveDataLogging());
services.AddScoped<ICookieRepository, CookieRepository.CookieRepository>();
}
DbContext:
public partial class OlqtContext : DbContext
{
private readonly ICookieRepository _cookieRepository;
public OlqtContext(DbContextOptions<OlqtContext> options, ICookieRepository cookieRepository)
: base(options)
{
ChangeTracker.QueryTrackingBehavior = QueryTrackingBehavior.NoTracking;
_cookieRepository = cookieRepository;
}
}
public override Task<int> SaveChangesAsync(CancellationToken cancellationToken = default)
{
var loginId = _cookieRepository.LoginId;
var dateTimeNow = DateTime.Now;
ChangeTracker.DetectChanges();
var modified = ChangeTracker.Entries().Where(x => x.State == EntityState.Added || x.State == EntityState.Modified || x.State == EntityState.Deleted);
foreach (var item in modified)
{
if (item.Entity is IAuditable entity)
{
if (item.State == EntityState.Added)
{
item.CurrentValues[nameof(IAuditable.CreatedByUserId)] = loginId;
item.CurrentValues[nameof(IAuditable.CreatedDate)] = dateTimeNow;
}
item.CurrentValues[nameof(IAuditable.LastModifiedByUserId)] = loginId;
item.CurrentValues[nameof(IAuditable.LastModifiedDate)] = dateTimeNow;
}
}
return base.SaveChangesAsync(cancellationToken);
}
Interface/Repo:
*Interface**
using System;
using System.Collections.Generic;
using System.Text;
namespace Olqt.CookieRepository
{
public interface ICookieRepository
{
public int LoginId { get; set; }
}
}
**Repo:**
using System;
using System.Collections.Generic;
using System.Text;
namespace Olqt.CookieRepository
{
public class CookieRepository : ICookieRepository
{
public int LoginId { get; set; }
}
}
The login ID is set here, in the loginrepo I created.
public partial class LoginRepository : GenericRepository<Login, LoginDto>, ILoginRepository
{
private readonly ICookieRepository _cookieRepository;
public LoginRepository(IDbContextFactory<OlqtContext> dbFactory, IMapper mapper, ICookieRepository cookieRepository) : base(dbFactory, mapper, cookieRepository)
{
_cookieRepository = cookieRepository;
}
public async Task<LoginDto> VerifyLoginAsync(string username, string password)
{
using var _context = GetOlqtContext();
LoginDto retval = null;
var login = await _context.Logins.Where(x => x.UserName == username && x.Password == password).FirstOrDefaultAsync();
if (login != null)
{
var ReturnLogin = new LoginDto
{
UserName = login.UserName,
Password = login.Password,
CreatedByUserId = login.LoginId
};
retval = ReturnLogin;
_cookieRepository.LoginId = login.LoginId;
}
return retval;
}
}
This is the error i receive:
An unhandled exception occurred while processing the request.
InvalidOperationException: Cannot resolve scoped service 'Olqt.CookieRepository.ICookieRepository' from root provider.
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope)
InvalidOperationException: Cannot resolve scoped service 'Olqt.CookieRepository.ICookieRepository' from root provider.
Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteValidator.ValidateResolution(Type serviceType, IServiceScope scope, IServiceScope rootScope)
Microsoft.Extensions.DependencyInjection.ServiceProvider.Microsoft.Extensions.DependencyInjection.ServiceLookup.IServiceProviderEngineCallback.OnResolve(Type serviceType, IServiceScope scope)
Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope)
Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType)
Microsoft.Extensions.DependencyInjection.ActivatorUtilities.GetService(IServiceProvider sp, Type type, Type requiredBy, bool isDefaultParameterRequired)
lambda_method63(Closure , IServiceProvider , object[] )
Microsoft.EntityFrameworkCore.Internal.DbContextFactorySource<TContext>+<>c__DisplayClass4_0.<CreateActivator>b__1(IServiceProvider p, DbContextOptions<TContext> _)
Microsoft.EntityFrameworkCore.Internal.DbContextFactory<TContext>.CreateDbContext()
Olqt.Repository.Services.GenericRepository<T, T1>.GetOlqtContext() in GenericRepository.cs
return _dbFactory.CreateDbContext();
Olqt.Repository.Services.GenericRepository<T, T1>.GetAllAsync() in GenericRepository.cs
using var _context = GetOlqtContext();
Olqt.Server.Pages.Quote.Quote.OnInitializedAsync() in Quote.cs
Quotes = (await QuoteRepository.GetAllAsync())
Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
Microsoft.AspNetCore.Components.Rendering.HtmlRenderer.HandleException(Exception exception)
Microsoft.AspNetCore.Components.RenderTree.Renderer.AddToPendingTasks(Task task)
Microsoft.AspNetCore.Components.Rendering.ComponentState.SetDirectParameters(ParameterView parameters)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InitializeNewComponentFrame(ref DiffContext diffContext, int frameIndex)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InitializeNewSubtree(ref DiffContext diffContext, int frameIndex)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InsertNewFrame(ref DiffContext diffContext, int newFrameIndex)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InsertNewFrame(ref DiffContext diffContext, int newFrameIndex)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.InsertNewFrame(ref DiffContext diffContext, int newFrameIndex)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.AppendDiffEntriesForRange(ref DiffContext diffContext, int oldStartIndex, int oldEndIndexExcl, int newStartIndex, int newEndIndexExcl)
Microsoft.AspNetCore.Components.RenderTree.RenderTreeDiffBuilder.ComputeDiff(Renderer renderer, RenderBatchBuilder batchBuilder, int componentId, ArrayRange<RenderTreeFrame> oldTree, ArrayRange<RenderTreeFrame> newTree)
Microsoft.AspNetCore.Components.Rendering.ComponentState.RenderIntoBatch(RenderBatchBuilder batchBuilder, RenderFragment renderFragment)
Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderInExistingBatch(RenderQueueEntry renderQueueEntry)
Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
Microsoft.AspNetCore.Components.Rendering.HtmlRenderer.HandleException(Exception exception)
Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessRenderQueue()
Microsoft.AspNetCore.Components.RenderTree.Renderer.ProcessPendingRender()
Microsoft.AspNetCore.Components.RenderTree.Renderer.AddToRenderQueue(int componentId, RenderFragment renderFragment)
Microsoft.AspNetCore.Components.ComponentBase.StateHasChanged()
Microsoft.AspNetCore.Components.ComponentBase.CallOnParametersSetAsync()
Microsoft.AspNetCore.Components.ComponentBase.RunInitAndSetParametersAsync()
Microsoft.AspNetCore.Components.Rendering.HtmlRenderer.HandleException(Exception exception)
Microsoft.AspNetCore.Components.RenderTree.Renderer.AddToPendingTasks(Task task)
Microsoft.AspNetCore.Components.Rendering.ComponentState.SetDirectParameters(ParameterView parameters)
Microsoft.AspNetCore.Components.RenderTree.Renderer.RenderRootComponentAsync(int componentId, ParameterView initialParameters)
Microsoft.AspNetCore.Components.Rendering.HtmlRenderer.CreateInitialRenderAsync(Type componentType, ParameterView initialParameters)
Microsoft.AspNetCore.Components.Rendering.HtmlRenderer.RenderComponentAsync(Type componentType, ParameterView initialParameters)
Microsoft.AspNetCore.Components.Rendering.RendererSynchronizationContext+<>c__11<TResult>+<<InvokeAsync>b__11_0>d.MoveNext()
Microsoft.AspNetCore.Mvc.ViewFeatures.StaticComponentRenderer.PrerenderComponentAsync(ParameterView parameters, HttpContext httpContext, Type componentType)
Microsoft.AspNetCore.Mvc.ViewFeatures.ComponentRenderer.PrerenderedServerComponentAsync(HttpContext context, ServerComponentInvocationSequence invocationId, Type type, ParameterView parametersCollection)
Microsoft.AspNetCore.Mvc.ViewFeatures.ComponentRenderer.RenderComponentAsync(ViewContext viewContext, Type componentType, RenderMode renderMode, object parameters)
Microsoft.AspNetCore.Mvc.TagHelpers.ComponentTagHelper.ProcessAsync(TagHelperContext context, TagHelperOutput output)
Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperRunner.<RunAsync>g__Awaited|0_0(Task task, TagHelperExecutionContext executionContext, int i, int count)
Olqt.Server.Pages.Pages__Host.<ExecuteAsync>b__35_1() in _Host.cshtml
<component type="typeof(App)" render-mode="ServerPrerendered" param-InitialState="initialTokenState" />
Microsoft.AspNetCore.Razor.Runtime.TagHelpers.TagHelperExecutionContext.SetOutputContentAsync()
Olqt.Server.Pages.Pages__Host.ExecuteAsync() in _Host.cshtml
Layout = null;
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, bool invokeViewStarts)
Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, string contentType, Nullable<int> statusCode)
Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, string contentType, Nullable<int> statusCode)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|29_0<TFilter, TFilterAsync>(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext<TFilter, TFilterAsync>(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, object state, bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(ref State next, ref Scope scope, ref object state, ref bool isCompleted)
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
I'm trying to use IViewComponentHelper in a multi threaded manner. But it's throwing :( (see full exception at bottom of post)
System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.AspNetCore.Http.DefaultHttpContext.get_Items()
I have no idea why.
Here's my setup: (simplified for brevity)
Controller:
public async Task<IActionResult> Get()
{
var pdfStream = await _pdfService.GenerateAsync();
return File(pdfStream, "application/pdf");
}
PdfService:
public class PdfService
{
private readonly PdfSDK _pdfSDK;
public constructor(PdfSDK pdfSDK)
{
_pdfSDK = pdfSDK;
}
public async Task<Stream> GenerateAsync()
{
List<Task<PdfDocument>> tasks = await _context.Foos.Select(x => DoWorkAsync(x));
var pdfs = await Task.WhenAll(tasks);
var mergedPdf = _pdfSDK.MergePdfs(pdfs);
return mergedPdf.Stream;
}
private async Task<PdfDocument> DoWorkAsync(Foo foo)
{
var html = await _renderViewComponentService.RenderViewComponentAsStringAsync<MyViewComponent>(foo);
var document = await _pdfSDK.HtmlToDocumentAsync(html);
return document;
}
}
PdfSDK:
public class PdfSDK
{
public async Task<PdfDocument> HtmlToDocumentAsync(string html)
{
using var pdfEngine = new PdfEngine();
var pdf = await pdfEngine.HtmlAsPdfAsync(html);
return pdf;
}
public PdfDocument MergePdfs(params PdfDocument[] pdfs)
{
var pdf = PdfDocument.Merge(pdfs);
return pdf;
}
}
MyViewComponent:
public class MyViewComponent : ViewComponent
{
public IViewComponentResult Invoke(Foo args)
{
return View(args);
}
}
Default.cshtml
#model Foo
<h1>Hello from #Foo.Id<h1>
RenderViewComponentService:
public class RenderViewComponentService
{
private readonly IServiceProvider _serviceProvider;
private readonly ITempDataProvider _tempDataProvider;
private readonly IViewComponentHelper _viewComponentHelper;
public RenderViewComponentService(
IServiceProvider serviceProvider,
ITempDataProvider tempDataProvider,
IViewComponentHelper viewComponentHelper
)
{
_serviceProvider = serviceProvider;
_tempDataProvider = tempDataProvider;
_viewComponentHelper = viewComponentHelper;
}
public async Task<string> RenderViewComponentAsStringAsync<TViewComponent>(object args)
where TViewComponent : ViewComponent
{
var viewContext = GetFakeViewContext();
(_viewComponentHelper as IViewContextAware).Contextualize(viewContext);
// this appears to call InvokeAsync in TViewComponent, but it'll also call Invoke (synchronously) if it's implemented
// see https://learn.microsoft.com/en-us/aspnet/core/mvc/views/view-components?view=aspnetcore-3.1#perform-synchronous-work
var htmlContent = await _viewComponentHelper.InvokeAsync<TViewComponent>(args); // exception is thrown here!
using var stringWriter = new StringWriter();
htmlContent.WriteTo(stringWriter, HtmlEncoder.Default);
var html = stringWriter.ToString();
return html;
}
private ViewContext GetFakeViewContext(ActionContext actionContext = null, TextWriter writer = null)
{
actionContext ??= GetFakeActionContext();
var viewData = new ViewDataDictionary(new EmptyModelMetadataProvider(), new ModelStateDictionary());
var tempData = new TempDataDictionary(actionContext.HttpContext, _tempDataProvider);
var viewContext = new ViewContext(
actionContext,
NullView.Instance,
viewData,
tempData,
writer ?? TextWriter.Null,
new HtmlHelperOptions());
return viewContext;
}
private ActionContext GetFakeActionContext()
{
var httpContext = new DefaultHttpContext
{
RequestServices = _serviceProvider,
};
var routeData = new RouteData();
var actionDescriptor = new ActionDescriptor();
return new ActionContext(httpContext, routeData, actionDescriptor);
}
private class NullView : IView
{
public static readonly NullView Instance = new NullView();
public string Path => string.Empty;
public Task RenderAsync(ViewContext context)
{
if (context == null) { throw new ArgumentNullException(nameof(context)); }
return Task.CompletedTask;
}
}
}
Exception:
fail: Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware[1]
An unhandled exception has occurred while executing the request.
System.NullReferenceException: Object reference not set to an instance of an object.
at Microsoft.AspNetCore.Http.DefaultHttpContext.get_Items()
at Microsoft.AspNetCore.Mvc.Routing.UrlHelperFactory.GetUrlHelper(ActionContext context)
at Microsoft.AspNetCore.Mvc.Razor.RazorPageActivator.<>c__DisplayClass4_0.<.ctor>b__0(ViewContext context)
at Microsoft.Extensions.Internal.PropertyActivator`1.Activate(Object instance, TContext context)
at Microsoft.AspNetCore.Mvc.Razor.RazorPagePropertyActivator.Activate(Object page, ViewContext context)
at Microsoft.AspNetCore.Mvc.Razor.RazorPageActivator.Activate(IRazorPage page, ViewContext context)
at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, Boolean invokeViewStarts)
at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
at Microsoft.AspNetCore.Mvc.ViewComponents.ViewViewComponentResult.ExecuteAsync(ViewComponentContext context)
at Microsoft.AspNetCore.Mvc.ViewComponents.DefaultViewComponentInvoker.InvokeAsync(ViewComponentContext context)
at Microsoft.AspNetCore.Mvc.ViewComponents.DefaultViewComponentHelper.InvokeCoreAsync(ViewComponentDescriptor descriptor, Object arguments)
at MyProject.Services.RenderViewComponentService.RenderViewComponentToStringAsync[TViewComponent](Object args) in MyProject\Services\RenderViewComponentService.cs:line ??
at MyProject.Services.PdfService.DoWorkAsync(Foo foo) in MyProject\Services\PdfService.cs:line ??
at MyProject.Services.PdfService.GenerateAsync() in MyProject\Services\PdfService.cs:line ??
at MyProject.Controllers.MyController.Get() in MyProject\Controllers\MyController.cs:line ??
at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Awaited|12_0(ControllerActionInvoker invoker, ValueTask`1 actionResultValueTask)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeInnerFilterAsync>g__Awaited|13_0(ControllerActionInvoker
invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task
lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.HeaderPropagation.HeaderPropagationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)
I think the problem is how I Contextualize the IViewComponentHelper. But I'm at a loss on how else to do it.
Can you spot anything I'm doing wrong?