Response filters¶

A response filter changes what an endpoint returns, depending on who asks, without touching the handler. Coworkee wraps Nextended.ResponseFilters for minimal APIs and MVC.

MyApp.Catalog/ResponseFilters/DashboardResponseFilter.cs

using Coworkee.ResponseFilters;
using Nextended.ResponseFilters;

internal sealed class DashboardResponseFilter : ResponseFilter<DashboardDto>
{
    public DashboardResponseFilter()
    {
        Nullify(d => d.Users).UnlessGranted(IdentityPermissions.Users.View);
        Nullify(d => d.Roles).UnlessGranted(IdentityPermissions.Roles.View);
    }
}

MyApp.Api/MyAppApiModule.cs

context.Services.AddCoworkeeResponseFilters([typeof(MyAppCatalogModule).Assembly]);

AddCoworkeeResponseFilters finds all filters in the given assemblies and applies them to every group created with MapCoworkeeApi and to MVC results.

Rules¶

Rule	Effect
`Remove(x => x.Token)`	the property disappears from the JSON
`Nullify(x => x.Salary)`	the property is sent as `null`
`Mask(x => x.Card).KeepFirst(4).KeepLast(4)`	`4111********1111`
`Hash(x => x.Email).AsSha256()`	a stable hash instead of the value

Each rule ends with a condition: .Always(), .When(...), .Unless(...), or the Coworkee shortcuts .WhenGranted(permission) and .UnlessGranted(permission).

OData

OData serializes its own results. Filters skip them; hide internal properties in the model instead (AddODataEntity<T>(set, permission, x => x.Secret)), and narrow rows with an entity filter.