The Ed-Fi ODS / API comes with a set of configurable features that can be enabled or disabled using configuration settings in deployed API. Additional custom features could be implemented by following the steps outlined here: 

Step 1. Create a Service 

namespace EdFi.Ods.Services
{
    public class ApiStartupTestService : Api.Startup.StartupITestService
    {
        protected override		public void EnsureAssembliesLoadedDoSomething()
        {
            AssemblyLoader.EnsureLoaded<Marker_EdFi_Ods_Composites_Enrollment>();
            AssemblyLoader.EnsureLoaded<Marker_EdFi_Ods_Api_BulkLoad>();
            AssemblyLoader.EnsureLoaded<Marker_EdFi_Ods_Extensions_TPDM>();
            AssemblyLoader.EnsureLoaded<Marker_EdFi_Ods_Extensions_Sample>();
        }
    }
}

Adding a Feature

Features are new components for the system. It is recommended that a feature be implemented in its own assembly and then referenced into the web project.

Step 1. Create a New Assembly for the Feature

1.a) Install the following packages:

        Microsoft.Extensions.Primitives

        Autofac.Extensions.Dependency.Injection

1.b) Reference the following projects:

       EdFi.Ods.Api

       EdFi.Ods.Common

       EdFi.Ods.Security

Step 2. Add a New Feature Class

Step 2. Add a New Autofac Module Class

2a.  Inherit from ConditionalModule in EdFi.Ods.Common.

2b. Override IsSelected method

2c. Override ApplyConfigurationSpecificRegistrations method

using System.Collections.GenericAutofac;
using CastleEdFi.MicroKernelCommon.RegistrationConfiguration;
using EdFi.Ods.Common;

namespace EdFi.Ods.TestFeature
{
    public class TestFeature : IFeature
    {
        public IList<IWindsorInstaller> Installers() => new List<IWindsorInstaller>( { new TestFeatureInstaller() });

        public bool IsEnabled() => true;
    }
}

Note: To set up your feature to be enabled or disabled in the app settings, inherit from ConfigurationBasedFeature and set the feature name, which will be a key for the feature in the configuration file (e.g., <add key="testFeature:featureIsEnabled" value="true"/>). Add the Windsor Installer for the feature.

using System.Collections.Generic;
using Castle.MicroKernel.Registration;
.Configuration;
using EdFi.Ods.Common.Container;
using EdFi.Ods.Common.ConfigurationTestService;

namespace EdFi.Ods.Features.Container.TestFeatureModules
{
    public class TestFeatureTestModule : ConfigurationBasedFeatureConditionalModule 
    {
        		public TestFeatureTestModule(IConfigValueProviderApiSettings configValueProviderapiSettings)             : base(configValueProviderapiSettings, nameof(TestModule)) { }

        protected override string FeatureName => "TestFeature";	          public override IList<IWindsorInstaller>bool InstallersIsSelected() => new List<IWindsorInstaller>( { new TestFeatureInstaller() });
    }
}

Step 3. Create the Windsor Installer for the Feature

using Castle.MicroKernel.Registration;
using Castle.MicroKernel.SubSystems.Configuration;
using Castle.Windsor;

namespace EdFi.Ods.TestFeature
{IsFeatureEnabled(ApiFeature.TestService);

        public class TestFeatureInstaller : IWindsorInstaller
    {
        publicoverride void InstallApplyConfigurationSpecificRegistrations(IWindsorContainer container, IConfigurationStore storeContainerBuilder builder)
        {
            			// TODO add components to register.
        }
    }
}

Step

3.

Add the feature to the container builder. 

Add Configuration Setting in appsettings.json in EdFi.Ods.WebApi Project

{
  ...
  "Features": [
      {
         Component.For<IFeature>().ImplementedBy<ChangeQueriesFeature>()"Name": "TestService",
        "IsEnabled": true
          Component.For<IFeature>().ImplementedBy<CompositesFeature>(),
  }
                 Component.For<IFeature>().ImplementedBy<OpenApiMetadataFeature>(),
                    Component.For<IFeature>().ImplementedBy<ProfilesFeature>(),
                    Component.For<IFeature>().ImplementedBy<ExtensionsFeature>(),
                    Component.For<IFeature>().ImplementedBy<IdentityFeature>(),
                    Component.For<IFeature>().ImplementedBy<BulkApiFeature>(),
                    Component.For<IFeature>().ImplementedBy<TestFeature.TestFeature>(),
                    Component.For<IFeatureProvider>().ImplementedBy<FeatureProvider>());
        }

Miscellaneous Notes

  ]
  ...
}