Zack Owens

Cache Abstraction

zowens — Mon, 04 Aug 2008 21:08:04 GMT

I'm in the middle of a project and I wrote my own Cache logic that melds nicely to my project's needs. But how do I test it? I can't mock the System.Web.Caching.Cache class. So I looked in the Abstractions that ship with ASP.NET MVC. What do you know, they're not there!

So I created my own base class and wrapper. Here's the code. Enjoy.

using System;
using System.Collections;
using System.Web.Caching;

namespace WebCommon.Abstractions
{
    public abstract class CacheBase : IEnumerable
    {
        public abstract int Count { get; }
        public abstract long EffectivePercentagePhysicalMemoryLimit { get; }
        public abstract long EffectivePrivateBytesLimit { get; }
        public abstract object this[string key] { get; set; }
        public abstract object Add(string key, object value, CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, CacheItemRemovedCallback onRemoveCallback);
        public abstract object Get(string key);
        public abstract IDictionaryEnumerator GetEnumerator();
        public abstract void Insert(string key, object value);
        public abstract void Insert(string key, object value, CacheDependency dependencies);
        public abstract void Insert(string key, object value, CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration);
        public abstract void Insert(string key, object value, CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, CacheItemRemovedCallback onRemoveCallback);
        public abstract object Remove(string key);

        IEnumerator IEnumerable.GetEnumerator()
        {
            return this.GetEnumerator();
        }
    }
}

using System;
using System.Collections;
using System.Web.Caching;

namespace WebCommon.Abstractions
{
    public class CacheWrapper : CacheBase
    {
        private Cache _cache;

        public CacheWrapper(Cache cache)
        {
            _cache = cache;
        }

        public override int Count
        {
            get { return _cache.Count; }
        }

        public override long EffectivePercentagePhysicalMemoryLimit
        {
            get { return _cache.EffectivePercentagePhysicalMemoryLimit; }
        }

        public override long EffectivePrivateBytesLimit
        {
            get { return _cache.EffectivePrivateBytesLimit; }
        }

        public override object this[string key]
        {
            get
            {
                return _cache[key];
            }
            set
            {
                _cache[key] = value;
            }
        }

        public override object Add(string key, object value, CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, CacheItemRemovedCallback onRemoveCallback)
        {
            return _cache.Add(key, value, dependencies, absoluteExpiration, slidingExpiration, priority, onRemoveCallback);
        }

        public override object Get(string key)
        {
            return _cache.Get(key);
        }

        public override IDictionaryEnumerator GetEnumerator()
        {
            return _cache.GetEnumerator();
        }

        public override void Insert(string key, object value)
        {
            _cache.Insert(key, value);
        }

        public override void Insert(string key, object value, CacheDependency dependencies)
        {
            _cache.Insert(key, value, dependencies);
        }

        public override void Insert(string key, object value, CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration)
        {
            _cache.Insert(key, value, dependencies, absoluteExpiration, slidingExpiration);
        }

        public override void Insert(string key, object value, CacheDependency dependencies, DateTime absoluteExpiration, TimeSpan slidingExpiration, CacheItemPriority priority, CacheItemRemovedCallback onRemoveCallback)
        {
            _cache.Insert(key, value, dependencies, absoluteExpiration, slidingExpiration, priority, onRemoveCallback);
        }

        public override object Remove(string key)
        {
            return _cache.Remove(key);
        }
    }
}

ClubStarterKit - where do we go?

zowens — Wed, 30 Jul 2008 01:40:28 GMT

Wow, what a year. Not exactly what I'd expected. Before I dive into where we are now, let me preface this post by saying I have NOT forgotten ClubStarterKit! Although I was not the original author, I feel like it's my baby. I can't just forget about it. Not going to happen.

You might be quick to point out that I have done virtually nothing since the v3 beta 1 release. This, my friends, was a big mistake. Not v3 beta 1, which I will discuss later in this post, but the fact that I was not clear in what I hope to get out of the project. I do take the blame on the lack of development. I'm not going to sit here and tell you I have neglected to look at the code in a while. This is partially due to my work life (I have to make some money.. know that I have 2 jobs) and my personal endeavors (as I am a high school student with more to do than dedicate all my time to ClubStarterKit). No one is perfect. But I do sincerely apologize to the ClubStarterKit community for my lack of communication.

My hopes from the project

When I started the project, I knew that there was a void. ClubStarterKit v1 was an obvious success because of the idea of sample-driven learning. It did a lot of things that people needed. Now, I really wanted to bring CSK to the level of open source. With this, I opened up the door for contributors. This is an area that I found fairly problematic. We did get some amazing contributions, such as the CMS and the RSVP system. Without these core contributions, I would have spent more time building the features rather than tracking down bugs or expanding other CSK features. Trust me, building out a feature for CSK is not easy.

Essentially I had hoped for the ClubStarterKit to be a community effort where there would be multiple core developers. In my idea of "core developer", I seem to be the only one. To me, CSK seems more like a sample that goes through active development.

It is my hope to not be a nag about this, but come on CSK community. You guys do some amazing stuff. Then you demand something out of CSK without contributing? I just don't see how this whole thing can work out like this. I'm not a free contractor. I don't even ask for donations!

I have been asked by one member of the community to forget my role in CSK and pass it along to another developer. Guess what, no one stepped up. Interesting. Guess it looks like I'm still in, win or lose.

What's the deal with the inactivity?

Like I said, there are many factors to this. Mostly, I am starting to regret hard-coding SubSonic into CSK. I now know, after completely hard-coding this stuff in, that I should have allowed external DALs that people wanted. Not everybody like SubSonic and it's query tool. Some people like NHibernate, LINQtoSQL, XML, whatever. I seriously screwed up. My fault, guys. I've learned, let's move on.

A big reason for inactivity was time. I just couldn't devote a lot of time on CSK like I used to. Luckily, this is about to change for me. Just know that I'm going to have more time to work on CSK. Period.

What's next?

I hate to say it, but v3 beta 1 was kind of bad. I really wanted something fresh. That just wasn't what we got with v3 beta 1. The ideas were there, just the delivery was poor. So this is what I plan on doing. What I want to do, and I would LOVE to hear feedback from you on this, is to completely scrap the current codebase and move over to the ASP.NET MVC framework. I am seriously in love with ASP.NET MVC. Honestly, it will move development, deployment, and testability along. I am in the preliminary planning stages. Also, for development, I would like to use C# and convert the C# code over to VB. The fact that the original kit was released in both languages made it all the more appealing. With a refreshed codebase, we can make this process much easier on the person converting (probably me :) ).

Also, we will have an extensive service layer that can be extended to use a custom DAL or any form of data storage.

Lastly, the features listed in my last post will go in.

So, what do you think? I would LOVE to hear your feedback AS LONG AS IT IS PRODUCTIVE AND WILL BENEFIT THE PROJECT.

THANKS FOR YOUR CONTINUED UNDERSTADING CLUBSTARTERKIT COMMUNITY!

One-Line C# #1 : Remove Whitespace from a string

zowens — Fri, 27 Jun 2008 18:37:43 GMT

Thought I'd post a quick extension method that I made today. Hope it helps someone.

public static string RemoveWhitespace(this string str){    try    {        return new Regex(@"\s*").Replace(str, string.Empty);    }    catch (Exception)    {        return str;    }}

Misuse of Delegates???

zowens — Mon, 26 May 2008 23:39:00 GMT

In the evolution of the ideas presented in Java, C# has provided the idea of method delegation and delegates, which I'm sure you are well aware of. In C# 3.0 with the introduction of the LINQ, Lambdas were born. With Lambdas, we are able to provide an easy and elegant way to declare delegates. With great power, however, comes great responsibility. Is there a way to overuse Lambdas and Delegates? Here is a sample of code I've written:

/// <summary>/// If GZIP or DEFLATE compression is accepted/// by the user's browser, we will go ahead/// and compress the file upon the controller action/// </summary>/// <param name="controller">Controller to invoke Compression</param>public static void Compress(this Controller controller){    string gzip = "gzip";    string deflate = "deflate";     //DELEGATES    Func<string, bool> isAccepted = (encoding) => controller.Request.Headers["Accept-encoding"] != null && controller.Request.Headers["Accept-encoding"].Contains(encoding);    Action<string> setEncoding = (encoding) => controller.Response.AppendHeader("Content-encoding", encoding);     if (isAccepted.Invoke(gzip))    {        controller.Response.Filter = new GZipStream(controller.Response.Filter, CompressionMode.Compress);        setEncoding.Invoke(gzip);    }    else if (isAccepted.Invoke(deflate))    {        controller.Response.Filter = new DeflateStream(controller.Response.Filter, CompressionMode.Compress);        setEncoding.Invoke(deflate);    }}

As you can see from the code, I use the .NET built-in delegates of Action and Func to do the setting of the encoding and the determination of the encoding, respectively.

So here is my question: Is this a misuse of delegates? Should I be putting the code into a separate private method? What are your thoughts?

ASP.NET MVC CSS Sprite

zowens — Sun, 27 Apr 2008 04:24:00 GMT

A month ago, I wrote about my technique to output a CSS sprite for ASP.NET. Granted, I made a big mistake. I put WAY too much bloat into the post. Not a K.I.S.S. moment.

I have reworked my CSS sprite technique to be unique to MVC. I've used the most recent build of the MVC framework, which can be downloaded on Codeplex, to take advantage of ActionResult. What the ActionResult does is makes your controllers more testable and makes the execution of the controller more specific. Instead of a void, controllers now return an ActionResult (see Scott Guthrie's post on the interim release).

I have a download, see the bottom of the post, that includes a sample application and a class library that you can distribute with any MVC application. The sample pulls 2 images off the Internet, plugs them into a sprite through the Sprite controller.

What you get when you execute the Sprite controller is a sprite that looks like so:

What you do in your CSS file is reference the sprite URL and specify the background-position, width, and height.

Then with the following HTML:

you get the images separate from the sprite.

What you get is an easy-to-use API for sprite generation and faster-loading website (less HTTP requests per page) using sprites instead of multiple images. If you want all of the CSS editing to happen at runtime, see my original post of CSS Sprites for that code.

DOWNLOAD SAMPLE APPLICATION AND CODE

Source Code conversion as part of a Build Process

zowens — Sat, 12 Apr 2008 04:10:20 GMT

If you're like me, you want a particular piece of code in your particular language. For example, a lot of people want the Club Starter Kit 2.0, 3.0 in C# since it has been written in VB. Me being the lazy open source developer that doesn't get paid :), I keep delaying the CSK conversion to C# because of my personal stuff. Then I was thinking, what if it were a part of the build process? Then I wouldn't have to go through the arbitrary process of converting a whole application to another language for a release that I will most likely be changing.

Before I go ahead and implement this myself, I was wondering if anyone out in the community has done this sort of thing before? I'm sure it wouldn't be that hard, what with the CruiseControl.NET API being what it is. I have already scoped out some ideas of how to implement. But I was wondering if anyone has ever built this plugin.

PLEASE leave a comment on the blog or email me (zowens2009 at gmail dot com)

THANKS COMMUNITY! I will make you proud if this isn't out there ;)

High Interface diet

zowens — Tue, 11 Mar 2008 01:54:25 GMT

As long as I'm on the coding conventions track (as many of users have commented on my last post), I'll talk about a small coding convention I am trying to do.

I feel more compelled to push an interface into a property, method, or any declaration rather than an object type. Why push around List<string> when you can push around IList<string>? It seems like a much better design decision. It also seems that there is more flexibility as far as future extensions are concerned.

Come on, let's hear those thoughts :)

Coding Pet Peeves

zowens — Sun, 09 Mar 2008 19:32:40 GMT

Any experienced coder has pet peeves when it comes to reading other people's code or writing code. It might be that you don't like regions or that every method should have comments. But here are my two biggest pet peeves when it comes to C#.

Var abuse

WAY too many people are using var instead of a type. This might save your hand, but it doesn't do much for readability of your code. Don't get me wrong, it is VERY usefully at times. But only about 10% of var use is actually productive. The rest is just abuse!

Angle Bracket Abuse

Yes, we all know that C# has angle brackets, get over it :). If you have one statement inside of an if, while, do, for, foreach, or using, you DON'T NEED ANGLE BRACKETS! Take the following code sample I found in a starter kit for example:

lock (SyncLock){    if (_cancelRequested == false)    {        _cancelRequested = true;        if (_uploads != null)        {            foreach (FileUpload upload in _uploads)            {                upload.UploadAsyncCancel();            }        }    }                }

That same thing can be accomplished through this:

lock (SyncLock){    if (_cancelRequested == false)    {        _cancelRequested = true;        if (_uploads != null)            foreach (FileUpload upload in _uploads)                upload.UploadAsyncCancel();    }                }

Isn't the second better to read? Plus this saves lines. For those of you who get paid by line, go ahead and put those in there, fine, but for those of you who don't, make your code more readable!