RequestLifeCycleHandler.cs :  » Content-Management-Systems-CMS » N2 » N2 » Web » C# / CSharp Open Source

using System;
using System.Web;
using N2.Engine;
using System.Diagnostics;
using N2.Configuration;
using N2.Installation;
using N2.Web.UI;
using N2.Plugin;
using N2.Edit.Installation;

namespace N2.Web{
  /// <summary>
  /// Handles the request life cycle for N2 by invoking url rewriting, 
  /// authorizing and closing NHibernate session.
  /// </summary>
  [Service(typeof(IRequestLifeCycleHandler))]
  public class RequestLifeCycleHandler : IRequestLifeCycleHandler
  {
    readonly IErrorHandler errors;
    readonly IWebContext webContext;
    readonly EventBroker broker;
    readonly InstallationManager installer;
    readonly RequestPathProvider dispatcher;
    readonly IContentAdapterProvider adapters;

    protected bool initialized = false;
    protected bool checkInstallation = false;
    protected RewriteMethod rewriteMethod = RewriteMethod.RewriteRequest;
    protected string installerUrl = "~/N2/Installation/Begin/Default.aspx";

    /// <summary>Creates a new instance of the RequestLifeCycleHandler class.</summary>
    /// <param name="webContext">The web context wrapper.</param>
    /// <param name="broker"></param>
    /// <param name="installer"></param>
    /// <param name="dispatcher"></param>
    /// <param name="errors"></param>
    /// <param name="editConfig"></param>
    /// <param name="hostConfig"></param>
    public RequestLifeCycleHandler(IWebContext webContext, EventBroker broker, InstallationManager installer, RequestPathProvider dispatcher, IContentAdapterProvider adapters, IErrorHandler errors, EditSection editConfig, HostSection hostConfig)
        {
      checkInstallation = editConfig.Installer.CheckInstallationStatus;
            installerUrl = editConfig.Installer.InstallUrl;
      rewriteMethod = hostConfig.Web.Rewrite;
      this.webContext = webContext;
      this.broker = broker;
      this.adapters = adapters;
      this.errors = errors;
      this.installer = installer;
      this.dispatcher = dispatcher;
    }

    protected virtual void Application_BeginRequest(object sender, EventArgs e)
    {
      if (!initialized)
      {
        // we need to have reached begin request before we can do certain 
        // things in IIS7. concurrency isn't crucial here.
        initialized = true;
        if (webContext.IsWeb)
        {
          if (Url.ServerUrl == null)
            Url.ServerUrl = webContext.Url.HostUrl;
          if (checkInstallation)
            CheckInstallation();
        }
      }

      var data = dispatcher.GetCurrentPath();
      webContext.CurrentPath = data;
      if (data != null && !data.IsEmpty())
      {
        RequestAdapter adapter = adapters.ResolveAdapter<RequestAdapter>(data.CurrentPage.GetType());
        adapter.RewriteRequest(data, rewriteMethod);
      }
    }
    
    protected virtual void Application_AuthorizeRequest(object sender, EventArgs e)
    {
      if (webContext.CurrentPath != null && !webContext.CurrentPath.IsEmpty())
      {
        RequestAdapter adapter = adapters.ResolveAdapter<RequestAdapter>(webContext.CurrentPage.GetType());
        adapter.AuthorizeRequest(webContext.CurrentPath, webContext.User);
      }
    }

    /// <summary>Infuses the http handler (usually an aspx page) with the content page associated with the url if it implements the <see cref="IContentTemplate"/> interface.</summary>
    protected virtual void Application_AcquireRequestState(object sender, EventArgs e)
    {
      if (webContext.CurrentPath == null || webContext.CurrentPath.IsEmpty()) return;

      RequestAdapter adapter = adapters.ResolveAdapter<RequestAdapter>(webContext.CurrentPage.GetType());
      adapter.InjectCurrentPage(webContext.CurrentPath, webContext.Handler);
    }

        protected virtual void Application_Error(object sender, EventArgs e)
        {
            HttpApplication application = sender as HttpApplication;
            if(application != null)
            {
              Exception ex = application.Server.GetLastError();
        if(ex != null)
        {
          errors.Notify(ex);
        }
            }
    }

    protected virtual void Application_EndRequest(object sender, EventArgs e)
    {
      webContext.Close();
    }

    private void CheckInstallation()
    {
      bool isEditing = webContext.ToAppRelative(webContext.Url.LocalUrl).StartsWith("~/N2/", StringComparison.InvariantCultureIgnoreCase);
      if (!isEditing && !installer.GetStatus().IsInstalled)
      {
        webContext.Response.Redirect(installerUrl);
      }
    }

    #region IRequestLifeCycleHandler Members

    public void Initialize()
    {
      broker.BeginRequest += Application_BeginRequest;
      broker.AuthorizeRequest += Application_AuthorizeRequest;
      broker.AcquireRequestState += Application_AcquireRequestState;
      broker.Error += Application_Error;
      broker.EndRequest += Application_EndRequest;
    }

    #endregion
  }
}