Most of the changes are concerned with making the code easier to manage. This is important because it allows me to find bugs faster or avoid them altogether. I’ve also written a bundle of automated tests that will check every change I make from now on. They are probably not complete yet, but it certainly makes me more confident that there will be no major bugs in future updates.

There were also some bugs that needed to be fixed. Most importantly the template function that ignored custom options. Obviously, I’ve also paid extra attention to avoid making my previous mistake again.

Furthermore, I decided to drop backward compatibility for PHP 4. This means that, officially speaking, the plugin only works on WP 3.2 and up (older versions allow the use of PHP 4). However, if you are using PHP 5 but (for some reason) still an older version of WordPress, the plugin might work just fine. Generally speaking, you should keep up with the latest version if possible.

Any questions can be posted here in the comments, or on the support forum. If you encounter bugs or errors, please post them to the support forum (not here).

Thanks everyone, for taking an interest in this plugin and giving feedback! Let’s hope this update goes off without a hitch.

The problem was that I accidentaly saved some whitespace outside the code (right before the first <?php) and then released it without testing. WordPress doesn’t handle this very well, so this caused some trouble for those who updated early. This was corrected almost immediately, but only by retagging 4.0 to a working revision. A few people complained about this and I understand that it can be confusing.

Does that take care of the problems? Unfortunately it seems it does not. Particularly, the template tag (the_advanced_excerpt) does not apply custom settings anymore. For this reason, people who use the plugin in their themes like this should definitely not upgrade until 4.1. There may be more stupid bugs yet, so I am currently working on testcases to figure that out.

If you haven’t upgraded already, I would recommend not upgrading at the moment. Version 4.1 should be out soon, with cleaner code and better testing to remedy the current problems.

If you have upgraded already and the plugin is causing you trouble, then first of all I’m sorry for the inconvenience. You can use the support forum to find a solution or ask about the issue you’re having. I’ll try to be around often to answer questions.

I hope this takes care of it for now. As I said, 4.1 should be out soon to help us forget this terrible tragedy.

The GUI is fairly complete, but it will remain offline for a while until I’m satisfied with the back-end code. So for now, Penumbra is a CLI application.

How to be picky about backup software

There are two types of backup software: complicated, enterprise-ready behemoths and dumbed-down, user-friendly eye-candies. Together, they offer everything I need (and more), but I can only use one for each backup. Let the nitpicking begin…

The concept of making backups is really simple. It involves copying files and that’s it. In practice, it can be a real pain to get proper copies of files: A file may be in use or locked for some other reason by the operating system; the file has special security settings that do not survive a basic copy operation; the file is a junction or symbolic link of some sort; etc.. This is usually not a problem if you’re backing up your own documents, music and downloads, but files such as application data are often a problem for basic backup methods. Active programs – most of which run in the background – often keep a lock on their application data, preventing direct access. Of course one could copy a complete disk image when the operating system isn’t running (probably using an application from bootable CD or USB), but this is not ideal for most users… including me.

Enter the shadow

Windows XP and upwards provide a way to avoid locked files and thereby solve one of the biggest issues of making a proper backup. It’s called VSS, or Volume Shadow Copy service, or just Shadow Copy. What it does is create a snapshot of the filesystem while allowing applications (i.e., the ones that implement its interface) to bring their data in a consistent state. This snapshot has no locked files; permissions still count, but that’s what the administrator account is for.

This feature hasn’t gone unnoticed with many developers of backup software, but unfortunately most implementations are part of complicated applications (enterprise software gets all the goodies first…) and/or proprietary.

Shedding a light on Penumbra

This is where Penumbra comes in to fill the gap. Penumbra wants to be powerful backup application with a simple, yet flexible, interface and an open attitude towards extensibility. Before you mistake that sentence for manager mumbo-jumbo, let me elaborate a little. By ‘powerful’ I am not aiming too high; there will be no transaction management, resuming after network errors or anything that would be vital in an enterprise environment. Coorporations have money to buy these features elsewhere, and they probably already do so there is no need to target that group. Penumbra will be ‘powerful’ in that it does one thing and does it well, namely copying the files from a home computer that are or may be important to its users and making sure that they can be restored perfectly as if they were never molten/burnt/scratched off the hard disk.

The interface will be ‘flexible’ in a way that allows users to easily customize the way backups are made. Skilled users shouldn’t feel limited and novice users shouldn’t feel intimidated. That’s why I also intend to keep Penumbra simple. I hope I don’t have to clarify ‘simple.’ Another goal that fits the keyword ‘flexible’ is that backups should be restorable even if Penumbra is somehow not available or preferred. At this moment Penumbra can’t restore backups, so it’s a good thing backups can be restored by hand (and a file archiver).

Open ended

Because I love experimenting with other APIs even more than the concept of open source, this project will have both. First of all, after careful consideration, the code is available under a GPL license. Secondly, I intend to make certain parts of the backup engine extensible and others even replaceable through a plugin system of some sorts. I first have to figure this all out for C#/.NET, but after that it will be one of the first things I do (a complete GUI is also on that todo-list, by the way).

On the cutting edge

I know you can’t wait to make your next backup with Penumbra. Unfortunately, at the moment, it will require a little effort. You can grab the code from Penumbra’s GitHub repository, fire up Visual Studio (the free Express edition might work), start building and hope I didn’t forget to commit a critical file. Alternatively, I could provide a compiled binary, but that would take away the thrill of trying development code… also, it would be irresponsible of me to encourage using it for real backup purposes. Even though you can already make good backups that are probably 100% safe, I shouldn’t recommend it.

So, some final words on using the program: Check out the sample .json file and of course, run penumbra.exe /help before anything else. Next time I will write some more on using Penumbra and its development. Thanks for reading!

But not anymore!  You see, even though I haven’t been busy writing about programming doesn’t mean I haven’t been busy doing it all this time. This means I have a few interesting projects and ideas in the works, or in other words, more material to publish on this site and blog about.

WordPress is not what it used to be

After blowing the dust off the dashboard, I realized how outdated my website had become. My theme and set of plugins for WordPress were no longer compatible or didn’t take advantage of the cool new features. It was time for a makeover! Having made some themes for newer versions of WordPress recently, I decided to put that experience to good use and start working on a new theme. It got my approval yesterday after which I locked down the site for “renovations”.

What you are currently looking at is the result of an afternoon squashing bugs and editing content. The new look is more minimalistic than any of my previous designs. There is more emphasis on typography and the presentation of content. The simplicity of the templates also made it much easier for me to integrate new WordPress features (such as threaded comments, you should give them a try!).

What’s next?

I have noticed a lot of visitors come here looking for my WordPress plugin(s). For them I have good news: I am still actively maintaining the plugin. As a matter of fact, there will be an update soon that should improve the speed and stability of the text filter. I will also start working on a new (commissioned) plugin soon, which will likely be released here as well.

Other things that I will be posting about are Syme (my attempt to write an IRC client) and a backup utility for Windows I wrote in C#.

A quick update has been released that fixes this. The new safe release is now 0.2.2, which should be available from the WordPress plugin repository shortly.

The cause for this problem is the fact that PHP 4 can have mbstring enabled, but not support all its functions. Ironically.

By the way, this would be a good time to urge your host to update PHP. The version 4 releases are all historical now.

What new features are included?

Well, most importantly, multi-byte character support. The plugin has received a lot of attention on the Asian side of the world (judging from the pingbacks), but unfortunately it fails with Chinese, Japanese and a whole host of other character sets. Betty was the first to report this problem and kindly helped me solve it. The plugin now supports multi-byte character sets.

I should point out, though, that it will only work when the mbstring PHP extension is enabled on the host. Furthermore, using UTF-8 on your blog is the safest way to make everything work.

People who don’t have the mbstring extension need not worry, the plugin will continue to work but with multi-byte character support disabled.

Another effort to internationalise the plugin includes the support for translations. The plugin now comes with a language file that can be used for translation. The only languages that are currently available are English and Dutch, but additional translations can be made using the PO file. If you want to translate, but don’t know how: stay tuned, there will be a post on that shortly.

Many people have been complaining about the problematic implementation of the Advanced Excerpt plugin in templates (using $advancedexcerpt->filter()). Admittedly, this was a confusing method and besides, the plugin FAQ was slightly incorrect. Sorry to all users who have been trying to get this work for so long.

This problem should be solved with the new release, which introduces the_advanced_excerpt() function. Using advanced excerpts in your template is now as easy as using any of WordPress’ default template tags. Usage details can be found in the plugin FAQ.

One final new addition to the feature set is the ability to ignore custom excerpts (you know, the ones you can write manually for every post you publish). The default behaviour is to always use custom excerpts, but for some reason a blogger might change his mind. One setting changes the behaviour.

Other updates include consistency of the options page with the rest of the new WordPress 2.7 admin interface as well as a compatibility check (which was by far the least work).

So, go ahead and update the plugin and enjoy the new features! Also, feel free to inform me of problems or features you would like to see in a next version in the comments section.

Thanks to a number of useful tutorials over at gotoAndLearn() I was introduced to sound spectrums, bitmap filters and creating packages/classes in AS3.0. Of course I had to test myself to see if I had actually learned something. A music visualisation was the result!

Here is what it looks like (if the SWF file is buggy, please tell me how much I suck).

[flash http://basvd.com/wp-content/uploads/2008/05/smokescreendemo.swf w=400 h=360]

What it does is actually quite simple (once you’ve completed the previously mentioned tutorials, that is). Every time a frame is rendered it computes the sound spectrum. Flash has a function that does the comlicated stuff and then returns a set of values which describe how the sound is distributed in the frequency spectrum. Basically the same thing as those ‘jumping bars’ in your media player (or stereo). The visualisation plots this data on a bitmap object, which is then blurred and scrolled up depending on the overall volume. The process repeats itself over and over, which results in a smoke effect. Variations in volume usually create nice puffs of smoke.

I thought this was quite an interesting little project, so I created an ActionScript class which makes the visualisation easy to reuse in other Flash applications. Admittedly, this is my first well-structured ActionScript code ever. Please have a look at it and then proceed to critise my attempt at programming in the comments.

If you happen to like my creation and want to put it to good use, you can download the AS3.0 package. You are free to use and modify it without any limitations, but please let me know in case it’s a public project.

The music in the demo was made by PriZm at OC ReMix. A great website by the way.

But don’t worry, the good news is that the new verification method doesn’t conflict with your webhost’s protection techniques!

To everybody who uses this plugin: it will not work in WP 2.5. If it worked for you in previous version, then you will likely not need it in WP 2.5.

The solution I offered solves the problem in most cases, but it wasn’t really good. Main reason: I provided a patch for a pluggable function! Secondly, the solution was less secure than the original.

However, I have returned to this issue to come up with a better solution. Behold, a plugin to fix the problem! No need to modify any WordPress files, just upload the plugin and activate it.

I have also improved the fix: it is now just as secure as the original one. You should check out the code if you want to know why.

You write:

function foo()
{
   global $var;
}

PHP does:

function foo()
{
   $var =& $GLOBALS['var'];
}

Why does this matter? The manual knows the answer.

On another note: I have been working on a new theme for a while now. It’s probably going to be my best one yet, but I’ll let you judge about that. I am also developing a WordPress plugin at the moment, it will be released when I launch the theme.