The Razor Framework :: Part 1 :: Plugins/Extensibility

using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using System.Xml;
using Razor;
using Razor.Networking.AutoUpdate.Common;
using Razor.Networking.AutoUpdate.Common.Xml;

namespace Razor.Networking.AutoUpdate
{
	/// <summary>
	/// Summary description for UncPathAutoUpdateDownloader.
	/// </summary>
	public class UncPathAutoUpdateDownloader : AutoUpdateDownloader
	{		
		protected const string MY_TRACE_CATEGORY = @"'UncPathAutoUpdateDownloader'";

		/// <summary>
		/// Initializes a new instance of the FileCopyAutoUpdateManager class
		/// </summary>
		public UncPathAutoUpdateDownloader() : base()
		{
			
		}

		/// <summary>
		/// Instructs the AutoUpdateDownloader to query for the latest version available 
		/// </summary>
		/// <param name="progressViewer">The progress viewer by which progress should be displayed</param>
		/// <param name="options">The options that affect this downloader</param>
		/// <param name="productToUpdate">The product descriptor for the product that should be updated</param>
		/// <param name="updateAvailable">The download descriptor that describes the download that could potentially occur</param>
		/// <returns></returns>
		public override bool QueryLatestVersion(IProgressViewer progressViewer, AutoUpdateOptions options, AutoUpdateProductDescriptor productToUpdate, out AutoUpdateDownloadDescriptor updateAvailable)
		{
			updateAvailable = null;

			try
			{
				// use the web service to query for updates
				Debug.WriteLine(string.Format("Querying the 'Alternate Download Path' for the latest version of '{0}'.\n\tThe current product's version is '{1}'.\n\tThe current product's id is '{2}'.\n\tThe path is '{3}'.", productToUpdate.Name, productToUpdate.Version.ToString(), productToUpdate.Id, options.AlternatePath), MY_TRACE_CATEGORY);			
				XmlNode node = ManifestQueryEngine.QueryLatestVersionEx(options.AlternatePath, productToUpdate.Name, productToUpdate.Version.ToString(), productToUpdate.Id);
				
				// if the service returned no results, then there is no update availabe
				if (node == null)
				{
					// bail out 
					Debug.WriteLine(string.Format("No updates are available from the 'Alternate Download Path' at '{0}' for this product.", options.AlternatePath), MY_TRACE_CATEGORY);
					return false;
				}

				// otherwise create a reader and try and read the xml from the xml node returned from the web service
				XmlAutoUpdateManifestReader reader = new XmlAutoUpdateManifestReader(node);

				// using the reader we can recreate the manifeset from the xml
				AutoUpdateManifest manifest = reader.Read();	
				
				/*
				* now create a download descriptor that says, yes we have found an update.
				* we are capable of downloading it, according to these options.
				* the autoupdate manager will decide which downloader to use to download the update
				* */
				updateAvailable = new AutoUpdateDownloadDescriptor(manifest, this, options);		

				// just to let everyone know that there is a version available
				Debug.WriteLine(string.Format("Version '{0}' of '{1}' is available for download.\n\tThe download url is '{2}'.\n\tThe size of the download is {3}.", updateAvailable.Manifest.Product.Version.ToString(), updateAvailable.Manifest.Product.Name, updateAvailable.Manifest.UrlOfUpdate, this.FormatFileLengthForDisplay(updateAvailable.Manifest.SizeOfUpdate)), MY_TRACE_CATEGORY);

				return true;
			}	
			catch(ThreadAbortException)
			{

			}
			catch(Exception ex)
			{
				throw new Exception(ex.Message, ex);
			}
			return false;
		}
	}

		
}