Today I was cleaning up some of the trackback code for WordPress when a number of things struck me about Trackback, which I’m sure someone has thought of before but I’m surprised they haven’t been addressed in the specification.

First off, what is trackback? On movabletype.org there is a Beginner’s Guide to TrackBack that is pretty thorough. Interestingly though they mention the names of several “tools” that have implemented TrackBack (as <strong> no less) they don’t link to any of them. If you’re not familiar with Trackback go read the first section of that to get up to speed.

A commonly requested feature is the ability to send a trackback ping when editing an entry. This has been especially needed since we’ve implemented post status flags (so you can, for example, save your post as a draft and work on it later). There are a couple of logical steps to implementing this, the first of which being that we need to track what pings have and haven’t been sent yet. Then the posting code had to modified a bit to only send trackback pings when an entry was published, and to not ping a URI that had been pinged before, et cetera. Not terribly hard stuff, just a bit of code to go through and some testing to make sure everything worked right.

Now that we have a nice record of pings that have been sent, I thought it would be nice to add that data to the default template for WordPress, as Trackback suffers from the same one-way linking problem it was trying to solve. That is, if I trackback another site my ping will show up in their comments or their trackbacks, but there’s nothing on my site indicating I sent that ping.

Then I realized that this set of pinged URIs I had was close to useless. What does a URI like http://www.movabletype.org/mt/trackback/55 mean anyway? If you enter it in your browser you get an XML error back. If you append a query string to it with ?__mode=rss with some implementations you will get a RSS .91 feed of trackbacks sent from that entry, from which you could extract the actual URI of the resource that http://www.movabletype.org/mt/trackback/55 is relevant to, but what a hassle. You can sweep things like this under the rug with a convoluted “auto-discovery” functionality (which is using sloppily embedded RDF instead of <link>… why?) but these problems are easy enough to solve that they should be.

(A side note, a URI tied to a unique ID system specific to a particular software platform does very little to suggest permanence to me. Are we going to have sent ping URI link rot?)

Has it really been over a year? I can’t believe it.

An unassuming little script, called “autop” and titled New Lines to Paragraphs was one of my earliest attempts at massaging plain text into smart XHTML, and it has come a very long way since it first started. (See the legacy code.) The code is not perfect, and it may never be, but it has worked very well for an impressive number of people, and I value that.

The code has been improved significantly in the past few months as part of the WordPress codebase, and I’ve updated the code homepage to reflect these improvements. Cheers.

So your Author would be a terrible blogger if he didn’t point out that iTunes is now available for Windows. It was immediately installed, requiring a reboot (the box had not been rebooted for 32 days), and preceded to crash consistently on a seemingly random set of files. It works swimmingly with about 95% of the files, but certain albums, when played or imported, crash iTunes every single time. Winamp, Windows Media Player, and every other media player installed works fine with said files. That said, one is very impressed with many of the features and how consistent it seems with the Mac version. Except the feature where it moves files out of their meticulously chosen folder hierarchy and renames them, losing track information in the process. Every feature but that one. Yes, it is an option, however the option does not communicate the weight it carries.

Ironically, today is also the day one decided to never by a Mac because one’s PCs were significantly cheaper and of comprable quality, the Windows OS is sufficently stable, and because of the beautiful things Michael Heilemann was able to do with Windows. (Not to mention the wonderful things he does with WordPress.) Something similar will be attempted here as soon as time permits. One program, Windows FX, was bought months ago as a result of its attractive functionality.

Update: I just saw this quote and thought it was worth including:

“We’re going to fight illegal downloading by competing with it,” said Jobs. “We’re not going to sue it. We’re not going to ignore it. We’re going to compete with it.”

—Steve Jobs. No wonder people love this guy. Hat tip: Wired.

Update: Something similar, but much worse happened to Adam.

It’s an entirely pleasant, rainy day, so I thought it would be a wonderful time to get going with Noel’s PhotoStack. I grabbed the latest version available and uploaded it to the server.

Trying to be as true as to I would actually use a program like this, I didn’t read any of the documentation. Plus there’s a readme file, but it has no extension so opening it means no less than three or four dialogs in Windows XP. A .txt extension wouldn’t hurt anybody. It gave me a message that the storage directory wasn’t set up properly, which told me that I probably need to edit a configuration file of some sort. So I fire up SSH. A ls -lah (which I have aliased as ll) shows a config.php, which I guess is what I’m looking for.

I fire up the one true editor. There seems to be a little more at the top than necessary and it doesn’t say much, but that’s a personal peeve. The varible names seem logical (some camelCase going on) but the descriptions above each is not always helpful. Mostly it’s just $photosName. I’ve never used the program before, and the description “The name of your Photos section.” makes sense to me as an English sentence but I don’t quite grok its significance.

Next up is the path information, which could possibly be streamlined. First we have $dirRoot where PhotoStack seems to want the absolute path to the script. It recommends “$_SERVER[‘DOCUMENT_ROOT’].’/photos’ may work for you.” but even though that makes perfect sense I’ve dealt a lot with this in WordPress. More people have messed up DOCUMENT_ROOTs than you could ever imagine, there are a few other solutions that may be better. One I’ve had good success with is dirname(__FILE__). which works like a charm for finding the absolute path of the current directory. realpath() may also be helpful, but we use the first trick in WordPress. The next variable is the URI of where PhotoStack is located, with the instruction “no trailing slash.” This is another pet peeve, but an instruction like this should be avoided at all costs. No trailing slash there, should I have a trailing slash on $dirRoot? It didn’t say anything. It causes confusion. It’s programatically trivial to detect and remove a trailing slash on this variable, so why even bother the user? Don’t make me think.

There are a lot more configuration options, a lot. It suggests replacing “no” with “yes” or vice versa to change the value. While this is probably more intuitive than boolean values of true or false, I think spelling out “yes” or “no” several times is a little patronizing. I know, impossible to please.

Okay so I’m done with the configuration file, I reload the URI. Still doesn’t work! I’m guessing it’s time to go to the readme, probably the storage directory needs to have permissions set or something. There is no wrapping in the file, which means each paragraph stretches really far and to read it I’ll have to scroll horizontally in my editor. Wrapping at 72 characters would probably not be a bad idea. Fortunately I know a shortcut (ctrl + j) to fix this but that’s just luck. I find out the software is licensed under the Creative Commons Attribution-NoDerivs-NonCommercial license, which I suppose means I can never use this for a paying client and if I want to improve on the code and release the changes without explicit permission from Noel. If Noel fell off a cliff I suppose the code would be locked under the license and development would halt? I don’t know exactly, but that’s what goes through my mind. Generally I’m much more comfortable with more liberal licenses, be it MIT or GPL or Artistic or anything Free. Next it says:

Templates in PhotoStack are not licensed as part of PhotoStack. Therefore, they are not subject to the licensing terms of PhotoStack. I’m placing this decision in the realm of Mr. Allen… If anyone can lend some clarification that would be great.

That doesn’t inspire the greatest confidence, but I’m planning to modify the templates anyway so maybe I should worry. Finally at the end it tells me to chmod 777 the storage directory. Ah, what I needed to know. I have heard some peopl ecomplain about the liberal chmod requirement before, but it’s really only necessary because of the way most web servers are set up to execute PHP, which I suppose could change in the future. It’s no problem to me. I secure things at a much lower level.

I’m already at the command line so it’s a simple matter to modify the directory. No errors but the pictures don’t load. Whoops, I missed setting $webDir variable, probably because I was planning to talk about it but went off on a tangent. The default value of this is “http://yoursite.com/photos”, and this is splitting hairs but there are several domains expressly for this purpose and an RFC to back them up. It’s a good practice because since yoursite.com isn’t reserved, it could theorectically be taken by some unsavory character that used its ubiquity in examples in some malicious fashion. You never know.

It loads! However I click on the sample album and there’s something funky going on with the layout. Perhaps it has something to do with the size I set my thumbnails at (150×150, though I would like to just be able to say something like 150 px on its longest side and allow it to keep its proportion, or just 150 px wide all the time. I’m not crazy about every thumbnail being square). What ever it is it will have to wait until tomorrow because it is past my bedtime. Hopefully tomorrow I can start loading this thing up with photos.

“Matthew! How could you possibly be so nitpicky with this poor guy’s project? How would you like that if someone did that to your project?” Actually, I would be thankful and flattered. If I didn’t like Noel and think PhotoStack could be great I wouldn’t be spending time documenting my thoughts on it. Constructive feedback is golden to an open-minded developer.