source: trunk/sources/HeuristicLab.Services.WebApp/3.3/Controllers/WebAppControllerSelector.cs @ 12428

using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using System.Linq;
using System.Net.Http;
using System.Reflection;
using System.Web.Http;
using System.Web.Http.Controllers;
using System.Web.Http.Dispatcher;

namespace HeuristicLab.Services.WebApp.Controllers {
  public class WebAppHttpControllerSelector : DefaultHttpControllerSelector {
    private readonly HttpConfiguration configuration;
    private readonly IDictionary<string, HttpControllerDescriptor> controllers;
    private readonly PluginManager pluginManager = PluginManager.Instance;

    public WebAppHttpControllerSelector(HttpConfiguration configuration)
      : base(configuration) {
      this.configuration = configuration;
      pluginManager.Configuration = configuration;
      controllers = new ConcurrentDictionary<string, HttpControllerDescriptor>();
      LoadAppControllers();
    }

    private void LoadAppControllers() {
      var assembly = Assembly.GetExecutingAssembly();
      var assemblyTypes = assembly.GetTypes();
      var apiControllers = assemblyTypes.Where(c => typeof(ApiController).IsAssignableFrom(c)).ToList();
      foreach (var apiController in apiControllers) {
        var apiControllerName = apiController.Name.Remove(apiController.Name.Length - 10).ToLower();
        controllers.Add(apiControllerName, new HttpControllerDescriptor(configuration, apiControllerName, apiController));
      }
    }

    public override HttpControllerDescriptor SelectController(HttpRequestMessage request) {
      if (request == null) {
        throw new ArgumentNullException("request");
      }
      var parts = request.RequestUri.AbsolutePath.Split('/');
      int startIndex = parts.TakeWhile(part => part.ToLower() != "api").Count();
      if (parts.Length < startIndex + 2) {
        throw new ArgumentException("invalid request path");
      }
      string pluginName = parts[startIndex + 1].ToLower();
      string controllerName = parts[startIndex + 2].ToLower();
      // load controller
      if (pluginName == "app") {
        // from main app
        HttpControllerDescriptor controller;
        controllers.TryGetValue(controllerName, out controller);
        return controller;
      }
      // from plugin
      var plugin = pluginManager.GetPlugin(pluginName);
      if (plugin == null) {
        throw new ArgumentException(string.Format("invalid plugin '{0}'", pluginName));
      }
      return plugin.GetController(controllerName);
    }
  }
}