A Fluent Way of Exception Handling

Mon, 09 Dec 2013 00:00:00 +0000

While doing some filesystem work I encountered alot of AccessViolationExceptions because a file is being opened to write multiple times. Even after closing the file explicitly a short timeframe exists in which the file could not be opened again. The simplest approach for me was to retry openening the file until it worked. To allow a more easy and more general way to handle exceptions I developed a small extensible try-repeat-framework which allows me to configure waiting and repeating strategies and also to only react to specific exceptions. I have written it with a fluent interface which allows easy usage:

Parsing Web Asset Files

Wed, 04 Dec 2013 00:00:00 +0000

To parse versioned web asset filenames ala jquery-1.4.min.js I wrote a simple class

/// <summary>
/// simple class for describing a file library like 
/// jquery-1.4.min.js
/// bootstrap.min.css
/// libname-1.0.0.0.tag1.tag2.tag3.extension
/// ... etc
/// contains methods for parsing these kind of filenames
/// </summary>
public class FileLib
{
 /// <summary>
 /// regular expression for parsing the filename
 /// </summary>
 public static readonly string libRegex = @"((?<libname>[^.-]*)-?)((?<major>d+))?(.(?<minor>d+)(.(?<revision>d+)(.(?<build>d+))?)?)?(.(?<tags>.+))*";
 /// <summary>
 /// parses a path as a lib
 /// </summary>
 /// <param name="path"></param>
 /// <returns></returns>
 public static FileLib ParsePath(string path)
 {
 var filename = Path.GetFileName(path);
 return Parse(filename);
 }
 /// <summary>
 /// parses a filename as a file lib 
 /// </summary>
 /// <param name="filename"></param>
 /// <returns></returns>
 public static FileLib Parse(string filename)
 {
 var match = Regex.Match(filename, libRegex);
 match.NextMatch();
 var lib = match.Groups["libname"].Value ?? "";
 var major = match.Groups["major"].Value ?? "";
 var minor = match.Groups["minor"].Value ?? "";
 var revision = match.Groups["revision"].Value ?? "";
 var build = match.Groups["build"].Value ?? "";
 var tags = match.Groups["tags"].Value.Split('.');
 var extension = tags.LastOrDefault() ?? "";
 tags = tags.Reverse().Skip(1).Reverse().ToArray();
 var result = new FileLib()
 {
 Extension = extension,
 LibName = lib,
 Major = major,
 Minor = minor,
 Revision = revision,
 Build = build,
 Tags = tags

 };
 return result;
 }
 /// <summary>
 /// Major version number
 /// </summary>
 public string Major { get; set; }
 /// <summary>
 /// Minor version number
 /// </summary>
 public string Minor { get; set; }
 /// <summary>
 /// Revision Number
 /// </summary>
 public string Revision { get; set; }

 /// <summary>
 /// Build number
 /// </summary>
 public string Build { get; set; }

 /// <summary>
 /// Creates a version object for the Filelib. returns null if this is not possible
 /// </summary>
 /// <returns></returns>
 public Version GetVersion()
 {

 Version parsedVersion = null;
 try
 {
 var version = Major + "." + Minor + "." + Revision + "." + Build;
 while (version.EndsWith(".")) version = version.Substring(0, version.Length - 1);
 if (version == "") return parsedVersion;
 parsedVersion = new Version(version);
 }
 catch (Exception exception) { }
 return parsedVersion;

 }
 /// <summary>
 /// the name of the lib
 /// </summary>
 public string LibName { get; set; }
 /// <summary>
 /// the tags of the lib. e.g. min, intellisense, etc
 /// </summary>
 public IEnumerable<string> Tags { get; set; }
 /// <summary>
 /// the extension of the lib
 /// </summary>
 public string Extension { get; set; }
}

C# on toeb / notes

A Fluent Way of Exception Handling

Parsing Web Asset Files