SampleActivator.cs

/*==============================================================================================================================
| Author        Ignia, LLC
| Client        Ignia, LLC
| Project       Sample OnTopic Site
\=============================================================================================================================*/
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Controllers;
using Microsoft.AspNetCore.Mvc.ViewComponents;
using OnTopic.Data.Caching;
using OnTopic.Data.Sql;
using OnTopic.Editor.AspNetCore.Attributes;
using OnTopic.Editor.AspNetCore.Controllers;
using OnTopic.Editor.AspNetCore.Infrastructure;
using OnTopic.Internal.Diagnostics;
using OnTopic.Lookup;
using OnTopic.Mapping;
using OnTopic.Repositories;

namespace OnTopicTest {

  /*============================================================================================================================
  | CLASS: SAMPLE ACTIVATOR
  \---------------------------------------------------------------------------------------------------------------------------*/
  /// <summary>
  ///   Responsible for creating instances of factories in response to web requests. Represents the Composition Root for
  ///   Dependency Injection.
  /// </summary>
  public class SampleActivator : IControllerActivator, IViewComponentActivator {

    /*==========================================================================================================================
    | PRIVATE INSTANCES
    \-------------------------------------------------------------------------------------------------------------------------*/
    private readonly            ITypeLookupService              _typeLookupService;
    private readonly            ITopicMappingService            _topicMappingService;
    private readonly            ITopicRepository                _topicRepository;
    private readonly            IWebHostEnvironment             _webHostEnvironment;
    private readonly            StandardEditorComposer          _standardEditorComposer;

    /*==========================================================================================================================
    | CONSTRUCTOR
    \-------------------------------------------------------------------------------------------------------------------------*/
    /// <summary>
    ///   Establishes a new instance of the <see cref="SampleActivator"/>, including any shared dependencies to be used across
    ///   instances of controllers.
    /// </summary>
    /// <remarks>
    ///   The constructor is responsible for establishing dependencies with the singleton lifestyle so that they are available
    ///   to all requests.
    /// </remarks>
    public SampleActivator(string connectionString, IWebHostEnvironment webHostEnvironment) {

      /*------------------------------------------------------------------------------------------------------------------------
      | Verify dependencies
      \-----------------------------------------------------------------------------------------------------------------------*/
      Contract.Requires(connectionString, nameof(connectionString));
      Contract.Requires(webHostEnvironment, nameof(webHostEnvironment));

      /*------------------------------------------------------------------------------------------------------------------------
      | Initialize Topic Repository
      \-----------------------------------------------------------------------------------------------------------------------*/
      var sqlTopicRepository    = new SqlTopicRepository(connectionString);
      var cachedTopicRepository = new CachedTopicRepository(sqlTopicRepository);

      /*------------------------------------------------------------------------------------------------------------------------
      | Preload repository
      \-----------------------------------------------------------------------------------------------------------------------*/
      _topicRepository          = cachedTopicRepository;
      _typeLookupService        = new EditorViewModelLookupService();
      _topicMappingService      = new TopicMappingService(_topicRepository, _typeLookupService);
      _                         = _topicRepository.Load();

      /*------------------------------------------------------------------------------------------------------------------------
      | Establish standard editor composer
      \-----------------------------------------------------------------------------------------------------------------------*/
      _webHostEnvironment       = webHostEnvironment;
      _standardEditorComposer   = new StandardEditorComposer(_topicRepository, _webHostEnvironment);

    }

    /*==========================================================================================================================
    | METHOD: CREATE
    \-------------------------------------------------------------------------------------------------------------------------*/
    /// <summary>
    ///   Registers dependencies, and injects them into new instances of controllers in response to each request.
    /// </summary>
    /// <returns>A concrete instance of an <see cref="Controller"/>.</returns>
    public object Create(ControllerContext context) {

      /*------------------------------------------------------------------------------------------------------------------------
      | Validate parameters
      \-----------------------------------------------------------------------------------------------------------------------*/
      Contract.Requires(context, nameof(context));

      /*------------------------------------------------------------------------------------------------------------------------
      | Determine controller type
      \-----------------------------------------------------------------------------------------------------------------------*/
      var type = context.ActionDescriptor.ControllerTypeInfo.AsType();

      /*------------------------------------------------------------------------------------------------------------------------
      | Configure and return appropriate controller
      \-----------------------------------------------------------------------------------------------------------------------*/
      if (type == typeof(EditorController)) {
        return new EditorController(_topicRepository, _topicMappingService);
      }
      else {
        throw new InvalidOperationException($"Unknown controller {type.Name}");
      }

    }

    /// <summary>
    ///   Registers dependencies, and injects them into new instances of view components in response to each request.
    /// </summary>
    /// <returns>A concrete instance of an <see cref="Controller"/>.</returns>
    public object Create(ViewComponentContext context) {

      /*------------------------------------------------------------------------------------------------------------------------
      | Validate parameters
      \-----------------------------------------------------------------------------------------------------------------------*/
      Contract.Requires(context, nameof(context));

      /*------------------------------------------------------------------------------------------------------------------------
      | Determine view component type
      \-----------------------------------------------------------------------------------------------------------------------*/
      var type = context.ViewComponentDescriptor.TypeInfo.AsType();

      /*------------------------------------------------------------------------------------------------------------------------
      | Configure and return appropriate view component
      \-----------------------------------------------------------------------------------------------------------------------*/
      if (StandardEditorComposer.IsEditorComponent(type)) {
        return _standardEditorComposer.ActivateEditorComponent(type, _topicRepository);
      }

      throw new InvalidOperationException($"Unknown view component {type.Name}");

    }

    /*==========================================================================================================================
    | METHOD: RELEASE
    \-------------------------------------------------------------------------------------------------------------------------*/
    /// <summary>
    ///   Responds to a request to release resources associated with a particular controller.
    /// </summary>
    public void Release(ControllerContext context, object controller) { }

    /// <summary>
    ///   Responds to a request to release resources associated with a particular view component.
    /// </summary>
    public void Release(ViewComponentContext context, object viewComponent) { }

  } //Class
} //Namespace