Web Caching, Part 1: Explicit Content Expiration

InformIT.com has published Reap the Benefits of Web Caching, Part 1: Explicit Content Expiration; the first article in my three-part series covering usage of web caching mechanisms in dynamic web pages.

Flash and Search Engines

This article gives you an excellent idea how to use Flash in your web sites while still having them completely visible to the search engines.

Detect included libraries in ASP

My ASP applications rely a lot on included libraries. As I usually end up with a complex hierarchy of libraries, it's not always possible to include the required modules in the dependent library. This makes debugging a bit more interesting, as you cannot be sure all the prerequisites have been included in the main .asp page unless you test all code paths.

To work around this problem, I wrote a small routine that checks for existence of prerequisite functions and throws an exception documenting what went wrong.

'
' CheckIncludedLibrary - checks if the incRoutine is available, 
'   otherwise throws an exception documenting that srcLibrary 
'   needs incLibrary
'
Sub CheckIncludedLibrary(incRoutine,srcLibrary,incLibrary)
  Dim routineRef
  
  On Error Resume Next
  Set routineRef = GetRef(incRoutine)
  If Err.Number <> 0 Then On Error Goto 0 : _
    Err.Raise vbObjectError+1,srcLibrary, _
    "You have to include " & incLibrary
End Sub

You would use this routine in a way similar to the example below:

'
' This library requires inclusion of /forms/xmlLibrary.asp, 
' /forms/lib/editLibrary.asp and /asp/incPostingPreview.asp
'

CheckIncludedLibrary "NewXMLTextElement", _
  "listRoutesLibrary","/forms/xmlLibrary"
CheckIncludedLibrary "EnrichElementText", _
  "listRoutesLibrary","/forms/lib/editLibrary"
CheckIncludedLibrary "PostToPreview", _
  "listRoutesLibrary","/asp/incPostingPreview"

“You've asked for it” series

Analyzing Google query strings that brought visitors to my blog (StatCounter is an excellent free tool to do this job), I usually find interesting (oft repeating) queries that are not yet answered in my blog. Obviously there are not too many good answers on other web sites, otherwise Google users would probably not click on a hit on the second or third page (where my blog usually appears for more generic queries).

So, to help my fellow programmers, I've started a series of “You've asked for it” posts answering the questions that brought many of you to my site in the first place (and, don't forget, you can always send me an interesting question with the Send a message link on my bio page.