What we were left with was a pretty simple method, but I think it could be made even more readable with a few tweaks. Here’s the code as it is after my changes:
private static void BuildCatalog()
{OnIndexBuilding();
bool commentsEnabled = BlogSettings.Instance.EnableCommentSearch;lock (_SyncRoot){_Catalog.Clear();
foreach (Post post in Post.PublishedPosts)
{AddItem(post);
if (commentsEnabled){foreach (Comment comment in post.ApprovedComments)
{AddItem(comment);
}
}
}
foreach (Page page in Page.PublishedPages)
{AddItem(page);
}
}
OnIndexBuild();
}
There are a three foreach() blocks working on List<> objects, and within each block there’s a single line of code. That kind of code is just begging to be made a bit more elegant.
The .NET Framework 2.0 added the List.ForEach() method, which allowed for something like:
post.ApprovedComments.ForEach(delegate(Comment comment){AddItem(comment);
}
Using a delegate, this syntax isn’t substantially better nor easier to read. However, toss in a lambda expression instead (introduced by .NET Framework 3.0), and ForEach() suddenly becomes juicily delicious:
post.ApprovedComments.ForEach(comment => AddItem(comment));
Yummy. All that blocky wordiness condensed to a simple, readable, one-line statement. Once we sprinkle those into our BuildCatalog() method, we may end up with something like:
private static void BuildCatalog()
{OnIndexBuilding();
lock (_SyncRoot){_Catalog.Clear();
if (BlogSettings.Instance.EnableCommentSearch){Post.PublishedPosts.ForEach(post => AddPostAndComments(post));
}
else{Post.PublishedPosts.ForEach(post => AddItem(post));
}
Page.PublishedPages.ForEach(page => AddItem(page));
}
OnIndexBuild();
}
Much cleaner code, I think. My final version of the Catalog class, after extracting it from the Search.cs file and adding a few more refactorings (like an extension method or two), looks like this:
public static class Catalog
{private static List<Entry> entries = new List<Entry>();
private readonly static object syncRoot = new object();
internal static List<Entry> Entries
{get { return entries; }}
internal static void AddItem(IPublishable item)
{item.AddToCatalog();
}
internal static void Build()
{OnIndexBuilding();
lock (syncRoot){entries.Clear();
Page.PublishedPages.ForEach(page => page.AddToCatalog());
if (BlogSettings.Instance.EnableCommentSearch){Post.PublishedPosts.ForEach(post => post.AddSelfAndCommentsToCatalog());
}
else{Post.PublishedPosts.ForEach(post => post.AddToCatalog());
}
}
OnIndexBuilt();
}
private static void AddSelfAndCommentsToCatalog(this Post post)
{post.AddToCatalog();
post.ApprovedComments.ForEach(c => c.AddToCatalog());
}
private static void AddToCatalog(this IPublishable item)
{var entry = new Entry{Item = item,
Title = TextAgent.CleanContent(item.Title, false),Content = HttpUtility.HtmlDecode(TextAgent.CleanContent(item.Content, true))};
if (item is Comment)
{entry.Content += HttpUtility.HtmlDecode(TextAgent.CleanContent(item.Author, false));}
entries.Add(entry);
}
public static event EventHandler<EventArgs> IndexBuilding;
private static void OnIndexBuilding()
{if (IndexBuilding != null)
{IndexBuilding(null, EventArgs.Empty);}
}
public static event EventHandler<EventArgs> IndexBuilt;
private static void OnIndexBuilt()
{if (IndexBuilt != null)
{IndexBuilt(null, EventArgs.Empty);}
}
}