I have added a filter to get "grouping" value either from query params or from body, but breakpoint on filter is only hit when I have passed query params to method, else not

FilterCode:

public class GroupingCodeFilter : IAsyncActionFilter
    {
        public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
        {
            var httpContext = context.HttpContext;
            var request = httpContext.Request;

            if (request.Query.TryGetValue("grouping", out var groupingFromQuery))
            {
                httpContext.Items["grouping"] = groupingFromQuery.ToString();
            }
 
            else if (context.ActionArguments.TryGetValue("model", out var value) &&
                     value is GridParamsModel gridModel &&
                     gridModel.ParameterDictionary != null &&
                     gridModel.ParameterDictionary.TryGetValue("groupingCode", out var groupingCodeObj))
            {
                var groupingCode = groupingCodeObj?.ToString();
                if (!string.IsNullOrEmpty(groupingCode))
                {
                    httpContext.Items["grouping"] = groupingCode;
                }
            }

            await next();
        }
    }

Method on which filter works :

[HttpPost("AddRecord")] 
[GroupingCodeFilter]
[DynamicTask(typeof(TaxCalendarAPIService.Controllers.GridServiceControllers.MaintainPaymentTypesController), "GetDynamicAaddRecordTaskAttributeID", "grouping")] 
public async Task<IActionResult> AddRecord([FromQuery] string grouping, [FromBody] CodeListDTO model) {} 

Method on which filter does not work :

[HttpPost("GetContent")]
[GroupingCodeFilter]
[DynamicTask(typeof(...), "GetDynamicTaskAttributeID", "grouping")]
public async Task<IActionResult> GetContent([FromBody] GridParamsModel model)
{}

On GetContent Method filter works if I pass queryparams or if I comment DynamicTaskAttribute

I have even tried to register filter in startup and then use it as but nothing worked

[ServiceFilter(typeof(GroupingCodeFilter))]

GetMethod shows error that The given key 'grouping' was not present in the dictionary

Somebody please help. I am just tired of this

I have added a filter to get "grouping" value either from query params or from body, but breakpoint on filter is only hit when I have passed query params to method, else not

FilterCode:

public class GroupingCodeFilter : IAsyncActionFilter
    {
        public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
        {
            var httpContext = context.HttpContext;
            var request = httpContext.Request;

            if (request.Query.TryGetValue("grouping", out var groupingFromQuery))
            {
                httpContext.Items["grouping"] = groupingFromQuery.ToString();
            }
 
            else if (context.ActionArguments.TryGetValue("model", out var value) &&
                     value is GridParamsModel gridModel &&
                     gridModel.ParameterDictionary != null &&
                     gridModel.ParameterDictionary.TryGetValue("groupingCode", out var groupingCodeObj))
            {
                var groupingCode = groupingCodeObj?.ToString();
                if (!string.IsNullOrEmpty(groupingCode))
                {
                    httpContext.Items["grouping"] = groupingCode;
                }
            }

            await next();
        }
    }

Method on which filter works :

[HttpPost("AddRecord")] 
[GroupingCodeFilter]
[DynamicTask(typeof(TaxCalendarAPIService.Controllers.GridServiceControllers.MaintainPaymentTypesController), "GetDynamicAaddRecordTaskAttributeID", "grouping")] 
public async Task<IActionResult> AddRecord([FromQuery] string grouping, [FromBody] CodeListDTO model) {} 

Method on which filter does not work :

[HttpPost("GetContent")]
[GroupingCodeFilter]
[DynamicTask(typeof(...), "GetDynamicTaskAttributeID", "grouping")]
public async Task<IActionResult> GetContent([FromBody] GridParamsModel model)
{}

On GetContent Method filter works if I pass queryparams or if I comment DynamicTaskAttribute

I have even tried to register filter in startup and then use it as but nothing worked

[ServiceFilter(typeof(GroupingCodeFilter))]

GetMethod shows error that The given key 'grouping' was not present in the dictionary

Somebody please help. I am just tired of this

• c#
• -core
• asp-core-webapi
• action-filter

• May I know what feature does DynamicTask attribute provide? You mentioned taht comment this attribute could solve the issue. – Tiny Wang Commented Mar 27 at 6:57

1 Answer 1

Accordting to the symptom, the exception is due to DynamicTask is trying to get grouping but failed. Since you didn't share what DynamicTask does in your question, I could only try to mock the exception.

Firstly, I make DynamicTask to implement IActionFilter like

public class DynamicTaskAttribute : Attribute, IAsyncActionFilter
{
    private readonly Type _controllerType;
    private readonly string _methodName;
    private readonly string _key;

    public DynamicTaskAttribute(Type controllerType, string methodName, string key)
    {
        _controllerType = controllerType;
        _methodName = methodName;
        _key = key;
    }

    public async Task OnActionExecutionAsync(ActionExecutingContext context, ActionExecutionDelegate next)
    {
        var httpContext = context.HttpContext;
        if (!httpContext.Items.TryGetValue(_key, out var value))
        {
            throw new KeyNotFoundException($"The given key '{_key}' was not present in the dictionary.");
        }
        var groupingValue = value?.ToString();
        await next();
    }
}

but I find that GroupingCodeFilter will execute before DynamicTaskAttribute because you have [GroupingCodeFilter] above [DynamicTask]. And because of the execution order, even if I don't have /GetContent?grouping=asdf in the url, my code still worked because GroupingCodeFilter already get value from GridParamsModel model and set it to httpContext.Items["grouping"]. Therefore, I'm sure DynamicTask is not an action filter but something else executed before Action Filter, for example, it's a resource filter/authorization filter/custom middleware.

Anyway, to fix this issue, we need to make sure there's an existing grouping key inside the Dictionary or make grouping key nullable. To ensure an existing grouping key, if we can adjust the execution order, then enforce GroupingCodeFilter to run before DynamicTask. If not, maybe we can adjust the input parameter in frontend codes, like getting the groupingCode from request content and append it to the url.