This takes the CFBundleVersion from the project’s Info.plist, adds a period and the subversion revision number, and injects that into the Info.plist of the built product.

When I made the move to Mercurial, I couldn’t quite do this anymore.  While subversion revision numbers are monotone increasing and consistent everywhere (they are the unique identifiers of a particular version), Mercurial’s “revision numbers” are local to a particular instance of the repository and may not match up from one instance to another.  Mercurial uses a hash as the unique identifier of a particular version, and these hexadecimal hashes are not monotone, making them unsuitable for use in CFBundleVersion.

Though it took some time, I’ve finally come to a system with Mercurial that I think is workable:

This calculates the number of minutes between the most recent tagged ancestor of the tip and the tip itself and adds that to the CFBundleVersion.  Because it’s time-based, it is guaranteed to be monotone increasing, consistent, and unique (well, provided multiple commits don’t happen within a 1-minute span, which is safe for me).

A little over a month ago, I went back and played with Mercurial some more, and it just clicked.  I think it had something to do with reading the Mercurial guide, but I couldn’t really put my finger on it.  That is, until a few days ago, when I read Distributed Version Control is here to stay, baby.  Joel’s explanation of his transition to DVCS really hit on the shift in thinking that took place for me in moving to Mercurial.  Plus, it has one of the best lines I’ve ever read in a blog post:

If the price is even remotely reasonable when the final version is available, I think I’ll be sticking with it.

At the moment, I’m just starting to dig into one of the larger web projects I’ve done, migrating a large, data-driven site from PHP4 to PHP5, moving it from a commercial host to my own hosting, and rewriting large swaths of code—all at once.  The previous webmaster, who wrote the original code, said he’d used subversion to deal with making revisions and having the ability to roll back when things broke, so I decided to look into subversion.

While most of the documentation made it seem really complex, once I’d settled on https access (apache mod_dav_svn), in the context of an existing SSL site I had, things were very easy–just a few svnadmin commands to set up the directories and a few lines of tweaking in an apache config file.  About 10 minutes into playing with the repository, having imported the existing site and set up a working copy on my local machine, I wondered if there weren’t some nice GUI way to deal with checkout/checkin/status/etc.  Enter svnX.

Now I’ve got working copies on my desktop and laptop as well as a copy checked out to the new production server and I can easily edit locally, even searching all files (that makes it a lot easier to fix all the instances of some incompatibility with PHP5 or some assumption about the directory structure or other oddity).  Once I’ve edited, I can easily check what’s been revised (status) and save the changes to the repository (checkin/commit) using svnX.  A quick “svn up” on the server and everything’s live.

This setup is so wonderfully easy that I’m annoyed I didn’t know to do it sooner.

Version 2.5.1 of WordPress is now available. It includes a number of bug fixes, performance enhancements, and one very important security fix. We recommend everyone update immediately, particularly if your blog has open registration. The vulnerability is not public but it will be shortly.

The notice also mentioned the SECRET_KEY thing that I talked about yesterday and gave a link to auto-generate the line for wp-config.php:

Since 2.5 your wp-config.php file allows a new constant called SECRET_KEY which basically is meant to introduce a little permanent randomness into the cryptographic functions used for cookies in WordPress. You can visit this link we set up to get a unique secret key for your config file. (It’s unique and random on every page load.) Having this line in your config file helps secure your blog.

Upgrading took me about 15 seconds (as usual), mostly to find the svn command in the codex again and then a few seconds to run it and a few seconds in hitting the “database upgrade” page on the site before things were all done.

Upgrade your blog to the latest WP. This shouldn’t be hard. There are plugins for it, if you’re techy use Subversion, there is the standard FTP method, and finally Media Temple, Dreamhost, and Bluehost (through SimpleScripts) all have been pretty good about having their one-click upgrade systems ready with new versions within a day or two of a release.

I’m techy, sure, but I don’t know much about subversion other than it seems to have replaced CVS and I didn’t know much of anything about CVS other than that people working on big OSS projects seemed to use it.  (Okay, I know a little more about what subversion and CVS are supposed to do, but I’ve never actually used a check-in/check-out/versioning system.)  I literally just installed subversion with the package manager on my system, then used the commands given in the WP Codex.  Not very techy-like.  Done.