Computer Programming

Yes, a bit specific, but I need to store some links!

Mutliple Time Sheets 6, Finally

This is a blog about the development of MTS 6, the next version of the wildly unpopular Multiple Timesheets.

It's one of those apps that just never took off. It was probably to quirky and personal, and worked a little funny compared to other solutions. Despite these problems, it helped me make money.

Lately, I've needed to track my time more closely, because work is getting overwhelming, and I'm letting it overwhelm me. I also need to get my finances in order.

Thus, the next version.

With new, exciting (yawn) features planned.

  • Uses a database!
  • Support for more than one user!
  • Track expenses!
  • Invoice for expenses *and* time!

Daylight Savings Time Misconfigurations between Computers Can Lead to Cumulative Data Errors

Symptom: my web app starting losing a day whenever I edited some data records. This app was working fine for a while, then, in March, it started losing time. Because my time was quantized to days, it looked like I was losing a day every time I saved the record.

The environment was a shared web hosting account, with PHP for the app, and a MySQL database behind it, on a separate machine.

According to a new law, starting in 2007, DST starts three weeks earlier than it has in the past.

I suspected that the problem is that one machine has the old style DST timezones, while the other machine has the new DST settings. So I created a test script to simulate the effect of multiple edits on a record.

Salary Surveys for Information Technology

2008-03-12: a report on Tech Republic. It's done by Global Knowledge

Web dev salary survey on Zeldman's A List Apart

Another popular survey is done by SAGE.

PHP List Hack: Shared Codebase

This is a trick to allow you to run one copy of the PHPList software on your server, and have separate configurations for each domain. The main advantage is that you don't have a bunch of copies of the same software all over the place. (PHPList takes up around 5 megs of disk. Using a similar technique with Drupal [which takes up 6 megs], we can install Drupal and PHPList in 260k of space, not including databases.)

At the top of index.php and admin/index.php, there's some code that looks for the config.php file. This new code snippet allowed me to create a config file named "phplist.config.php" in the user's root (or the ftp root) instead of the usual places.

Templating: A Minimalist Templating System

A few years back, my co-worker Josh and I came to the conclusion that we didn't like the Smarty templating system. Not that there's anything wrong with Smarty - it's just that we didn't like the fact it was this software system that didn't seem to do anything except behave like a subset of PHP, and required a lot of extra code.

So, we did some thinking, and thought a bit about Cold Fusion, a really nice language that gets little respect because it looks like HTML. There are a few things CF does to make life easier for HTMLers (but makes it a lousy development language for regular programmers). Some ideas bubbled to the top.

1. All variables are globals.
2. Most data is in arrays.

Object-Oriented Parser for iCalendar

Been working on a parser for ICS files, and it's done in an OO style - so that parts of the data become instantiated as objects, and the parse tree is a hierarchy of objects.

MS Access: Inserting and Deleting Contact Items With VBA

Gripe: VBA syntax is difficult. The object system is a little confusing too. It's just very hard to use. To make things even more difficult, the sample code out there is kind of *weird*. Maybe there's some good reasons for doing things their way, but, it just seems verbose, error prone, and hard to write, to me.

Here's some code that is the start of a library to work with Outlook's folders. It's based on some code samples from the web, refactored into something resembling a library.

The best feature is the function OLGetSubFolder, which returns a MAPI folder object for a given path. Totally useful.

OOXML, counter-standardization

Read this site: http://www.noooxml.org/

A site objecting to Microsoft's political promotion of their "open standard" years after the establishment of Open Document Format (ODF), a similar open standard used by the freely available OpenOffice and some other programs.

In response to the promulgation (and relative success) of the ODF formats, Microsoft is pushing OOXML, the confusingly named Office Open XML -- note the order of the two "O" words -- as an international open standard.

ODF is safer than OOXML, because the OpenOffice suite of programs is available in source code. The most popular parser for the ODF formats is always accessible to programmers, so they don't have to puzzle over the subtleties of the ODF.

Subversion Subtlety: A small error with redirects. (Error 301.)

(This isn't really DIY. It's more of a but report.)

I was getting consistent errors on one of my directories.

svn: Commit failed (details follow):
svn: OPTIONS request failed on '/images'
svn: OPTIONS of '/images': 301 Moved Permanently (http://svn.lolitics.org)

The problem was that the svn client was failing to honor the redirect request that sends requests for http://foo/bar to http://foo/bar/ with the trailing slash. I couldn't figure out why it was happening on this directory and not others.

After much research, I found only one reference to a similar problem: http://svn.haxx.se/users/archive-2005-09/0960.shtml

That thread, however, didn't provide the real solution.

The Wacky World of Software Copyright

At the bottom of the page http://www.etherboot.org/wiki/index.php there's a little story that illustrates, partly, why the more politicized internet and tech folks have an aversion to copyright. Typically, copyright is used to defend authors works from plagiarism. In this scenario, it was used to protect intellectual property that, perhaps, doesn't merit protection.

Update

Please note that some of the code for iSCSI booting of Windows has been temporarily taken out of the gPXE codebase at the request of Microsoft Corporation. One necessary part for iSCSI boot in Windows is the iBFT data structure which Microsoft claims is proprietary at this time.

Update 13 March 2007

MS Access: Printing the Range of Data on the Page on a Report

I wanted to print a report that indicated the first and last item on each page, just like a dictionary has. You know: "Azeri - Babcock", "Milk - Minder". It makes it easier to flip through printouts.

This is how to do it. It will put the range in the footer. I haven't figured out how to do one in the header, which is what I originally wanted, but found too difficult to do. (There is probably a way.)

First, take your report, and add an unbound field to your report. Rename it to "Range". See the picture below.

Then, set up event handlers for the On Print event of each section. An explanation follows the picture. Here's my code:

Option Compare Database
Option Explicit
Public FirstRow As String
Public CurrentRow As String

Future Web App Development

Things to read and research:

Adobe Flex
qooxdoo
Silverlight
OpenMocha
Backbase
Google Web Toolkit
Authenteo
WebKit

More info - Ajaxian

Not a framework - Scriptaculous which uses Prototype. (That and JQuery are in another post.)

MS Access: Logging Messages

Here's some code to help you log messages to a table. First, make a table called tblLog, with at least these columns: Timestamp, User, Computer, Message. (You don't need a primary key.)

Set the default value of Timestamp to NOW().

Copy the following code into a code module.

Also, add a reference to "Active DS Type something or other". It has the active directory functions you need to discover the username.

Function StartUp()
    Dim dummy
    dummy = LogOpen()
    DoCmd.OpenForm "frmHidden", acNormal, , , , acHidden
    StartUp = Null
End Function

Function LogOpen()
    LogMessage ("User opened database.")
End Function

Function LogClose()
    LogMessage ("User closed database.")
End Function

Function LogMessage(Mess As String)

MS Access: Application Configuration Settings in Tables

This is a relational way to store application configuration in a table. It uses two tables, so you can store multiple configurations, so that you can use the tool over and over, and still retain the old settings. One table stores configurations, and one stores a since row with the current configuration in use.

Setting values are retrieved from the configuration tables with queries like this:
(SELECT PreRegActivityID FROM Congress7_Config WHERE ID=(SELECT CurrentConfigID FROM Congress7_CurrentConfig))

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