{"id":931,"date":"2009-11-27T10:38:54","date_gmt":"2009-11-27T09:38:54","guid":{"rendered":"http:\/\/www.navision-blog.de\/2009\/11\/27\/observing-the-filesystem\/"},"modified":"2009-11-27T10:41:38","modified_gmt":"2009-11-27T09:41:38","slug":"observing-the-filesystem","status":"publish","type":"post","link":"http:\/\/www.navision-blog.de\/blog\/2009\/11\/27\/observing-the-filesystem\/","title":{"rendered":"Observing the FileSystem"},"content":{"rendered":"

The following class is a wrapper for the System.IO.FileSystemWatcher and converts the FileSystem events into observables. You need to download and reference the Reactive Extensions for .NET (Rx)<\/a> to use this code:<\/p>\n

\n

public<\/span> class<\/span> FileSystemObservable<\/span><\/p>\n

{<\/p>\n

  private<\/span> readonly<\/span> FileSystemWatcher<\/span> _fileSystemWatcher;<\/p>\n

 <\/p>\n

 <\/p>\n

  public<\/span> FileSystemObservable(string<\/span> directory, <\/p>\n

    string<\/span> filter, bool<\/span> includeSubdirectories)<\/p>\n

  {<\/p>\n

    _fileSystemWatcher =<\/p>\n

      new<\/span> FileSystemWatcher<\/span>(directory, filter)<\/p>\n

        {<\/p>\n

          EnableRaisingEvents = true<\/span>,<\/p>\n

          IncludeSubdirectories = includeSubdirectories<\/p>\n

        };<\/p>\n

 <\/p>\n

 <\/p>\n

    ChangedFiles = <\/p>\n

      Observable<\/span>.FromEvent<FileSystemEventHandler<\/span>, <\/span><\/p>\n

                             FileSystemEventArgs<\/span>><\/p>\n

      (h => h.Invoke,<\/p>\n

       h => _fileSystemWatcher.Changed += h,<\/p>\n

       h => _fileSystemWatcher.Changed -= h)<\/p>\n

      .Select(x => x.EventArgs);<\/p>\n

 <\/p>\n

    CreatedFiles = <\/p>\n

      Observable<\/span>.FromEvent<FileSystemEventHandler<\/span>,<\/p>\n

                             FileSystemEventArgs<\/span>><\/p>\n

      (h => h.Invoke,<\/p>\n

       h => _fileSystemWatcher.Created += h,<\/p>\n

       h => _fileSystemWatcher.Created -= h)<\/p>\n

      .Select(x => x.EventArgs);<\/p>\n

 <\/p>\n

    DeletedFiles = <\/p>\n

      Observable<\/span>.FromEvent<FileSystemEventHandler<\/span>, <\/p>\n

                             FileSystemEventArgs<\/span>><\/p>\n

      (h => h.Invoke,<\/p>\n

       h => _fileSystemWatcher.Deleted += h,<\/p>\n

       h => _fileSystemWatcher.Deleted -= h)<\/p>\n

      .Select(x => x.EventArgs);<\/p>\n

 <\/p>\n

    RenamedFiles = <\/p>\n

      Observable<\/span>.FromEvent<RenamedEventHandler<\/span>, <\/span><\/p>\n

                             RenamedEventArgs<\/span>><\/p>\n

      (h => h.Invoke,<\/p>\n

       h => _fileSystemWatcher.Renamed += h,<\/p>\n

       h => _fileSystemWatcher.Renamed -= h)<\/p>\n

      .Select(x => x.EventArgs);<\/p>\n

 <\/p>\n

    Errors = <\/p>\n

      Observable<\/span>.FromEvent<ErrorEventHandler<\/span>, ErrorEventArgs<\/span>><\/p>\n

      (h => h.Invoke,<\/p>\n

       h => _fileSystemWatcher.Error += h,<\/p>\n

       h => _fileSystemWatcher.Error -= h)<\/p>\n

      .Select(x => x.EventArgs);<\/p>\n

  }<\/p>\n

 <\/p>\n

  \/\/\/<\/span> <\/span><summary><\/span><\/p>\n

  \/\/\/<\/span> Gets or sets the errors.<\/span><\/p>\n

  \/\/\/<\/span> <\/span><\/summary><\/span><\/p>\n

  \/\/\/<\/span> <\/span><value><\/span>The errors.<\/span><\/value><\/span><\/p>\n

  public<\/span> IObservable<\/span><ErrorEventArgs<\/span>> Errors <\/p>\n

           { get<\/span>; private<\/span> set<\/span>; }<\/p>\n

 <\/p>\n

  \/\/\/<\/span> <\/span><summary><\/span><\/p>\n

  \/\/\/<\/span> Gets the changed files.<\/span><\/p>\n

  \/\/\/<\/span> <\/span><\/summary><\/span><\/p>\n

  \/\/\/<\/span> <\/span><value><\/span>The changed files.<\/span><\/value><\/span><\/p>\n

  public<\/span> IObservable<\/span><FileSystemEventArgs<\/span>> ChangedFiles <\/p>\n

           { get<\/span>; private<\/span> set<\/span>; }<\/p>\n

 <\/p>\n

  \/\/\/<\/span> <\/span><summary><\/span><\/p>\n

  \/\/\/<\/span> Gets the created files.<\/span><\/p>\n

  \/\/\/<\/span> <\/span><\/summary><\/span><\/p>\n

  \/\/\/<\/span> <\/span><value><\/span>The created files.<\/span><\/value><\/span><\/p>\n

  public<\/span> IObservable<\/span><FileSystemEventArgs<\/span>> CreatedFiles <\/p>\n

           { get<\/span>; private<\/span> set<\/span>; }<\/p>\n

 <\/p>\n

  \/\/\/<\/span> <\/span><summary><\/span><\/p>\n

  \/\/\/<\/span> Gets the deleted files.<\/span><\/p>\n

  \/\/\/<\/span> <\/span><\/summary><\/span><\/p>\n

  \/\/\/<\/span> <\/span><value><\/span>The deleted files.<\/span><\/value><\/span><\/p>\n

  public<\/span> IObservable<\/span><FileSystemEventArgs<\/span>> DeletedFiles <\/p>\n

           { get<\/span>; private<\/span> set<\/span>; }<\/p>\n

 <\/p>\n

  \/\/\/<\/span> <\/span><summary><\/span><\/p>\n

  \/\/\/<\/span> Gets the renamed files.<\/span><\/p>\n

  \/\/\/<\/span> <\/span><\/summary><\/span><\/p>\n

  \/\/\/<\/span> <\/span><value><\/span>The renamed files.<\/span><\/value><\/span><\/p>\n

  public<\/span> IObservable<\/span><RenamedEventArgs<\/span>> RenamedFiles <\/p>\n

           { get<\/span>; private<\/span> set<\/span>; }<\/p>\n

}<\/p>\n<\/p><\/div>\n

Now we can use the observable and can easily create meta-events:<\/p>\n

\n

IDisposable<\/span> writer =<\/p>\n

    new<\/span> FileSystemObservable<\/span>(@"d:\\Test\\"<\/span>, "*.*"<\/span>, false<\/span>)<\/p>\n

        .CreatedFiles<\/p>\n

        .Where(x => (new<\/span> FileInfo<\/span>(x.FullPath)).Length > 0)<\/p>\n

          \/\/ … you can do much more with the combinators<\/span><\/p>\n

        .Select(x => x.Name)<\/p>\n

        .Subscribe(Console<\/span>.WriteLine);<\/p>\n<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

The following class is a wrapper for the System.IO.FileSystemWatcher and converts the FileSystem events into observables. You need to download and reference the Reactive Extensions for .NET (Rx) to use this code: public class FileSystemObservable {   private readonly FileSystemWatcher _fileSystemWatcher;       public FileSystemObservable(string directory,     string filter, bool includeSubdirectories)   {     […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[579,578],"_links":{"self":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts\/931"}],"collection":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/comments?post=931"}],"version-history":[{"count":1,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts\/931\/revisions"}],"predecessor-version":[{"id":932,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/posts\/931\/revisions\/932"}],"wp:attachment":[{"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/media?parent=931"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/categories?post=931"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.navision-blog.de\/blog\/wp-json\/wp\/v2\/tags?post=931"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}