If you’re developing applications on the Mac, then you’re either familiar with, or about to become familiar with Xcode, Apple’s free development environment. I have been using Xcode for about five years now, if you count the time I spent with its predecessor, Project Builder. I am more or less happy with it, though of course I have my complaints.

Among the best changes in Xcode over the past few years has been increasingly improved scriptability, which means that the minor complaints one might have can often be remedied through a bit of automation. One of the things that has always bothered me about developing applications on the Mac is making certain that, with each version change, the correct values propagate to all the required points in the project. This is one of the most tedious and error-prone “chores” that needs to be tended to on a repeated basis. It used to mean changing ‘STR#’ resources to match ‘vers’ resources, and so on and so forth. On Mac OS X and with Xcode, it’s been pretty much reduced to editing a couple Info.plist keyed values: CFBundleGetInfoString and CFBundleShortVersionString.

Two is a nice, low number. Easy to manage, but it still means that whenever anything changes, it has to change in two tediously manual steps. Wouldn’t it be nice if you could store the version string for your application in one spot and have it be guaranteed that it would automatically appear in those two Info.plist keys?

Thanks to Xcode’s build value string substitution and its AppleScript scriptability, you can not only achieve this goal, but you can do it with panache and flair! The following steps will explain one method for easily configuring your projects such that, for all eternity, you can simply and quickly change the version string to whatever you desire with the flick of the wrist or the pressing of a keyboard shortcut.

1. Define a build setting for your application’s version string.

This will serve as the “central point of change” for your application’s “logical version number.” Examples of what this value may be set to include “1.0” or “1.7b1”, or even “1.Booyeah”. It’s up to you – whatever you consider the “base” version string to be, which you would normally go in and manually type into the two Info.plist keys mentioned above, you will now set as a separate, custom build setting. I named mine “APPLICATION_VERSION” and added it to the project’s build settings for “All Configurations.” Click the Top-Level project icon in Xcode, open the “Info” inspector, and open the “Build” pane. Now click the plus-sign icon to add a new setting, and type whatever name and initial version string you desire (or leave it bogus for now to prove that the script described below is working).

2. Replace hard-coded version strings with build-setting substitution markers.

Now that you’ve given Xcode an “APPLICATION_VERSION” or otherwise named build setting to store your version information inside of, you can replace any hard-coded version strings in your Info.plist file with the appropriate variable-expansion shorthand. For example, in my FastScripts project, I include the following declarations for the two Info.plist keys mentioned above:

<key>CFBundleGetInfoString</key>
<string>FastScripts ${APPLICATION_VERSION}, ©2003-2005 Red Sweater Software</string>
<key>CFBundleShortVersionString</key>
<string>${APPLICATION_VERSION}</string>	

(Note that because of a shortcoming in Xcode, this type of variable substitution will not be performed on your InfoPlist.strings file. This is a pretty good argument for moving these keys to the Info-MyProductName.plist file, though you will lose the ability to localize these keys in the process.)

You should now be able to build and run your application, open the “About Box” and observe the version strings were correctly substituted into your Info.plist keys. Go ahead, change the APPLICATION_VERSION build setting to something else, build and run again. Wasn’t that easy? It is easy, but not quite easy enough for my tastes.

3. Automate setting the APPLICATION_VERSION build setting.

It’s less tedious, but still annoying to have to go open the project inspector, locate the APPLICATION_VERSION build setting, and change it manually every time you want to release a newly versioned edition of your product. To make this truly as easy as developing on a Mac should be, we want to take advantage of Xcode’s AppleScript support to essentially add the “Change Application Version” dialog to Xcode. The following script accomplishes this. It asks the user for a new version string, and then iterates through all build configurations that advertise an APPLICATION_VERSION setting, changing the setting to the newly specified value.

Copy and paste the script below into your Script Editor, and run it. You will be prompted for a new string which, when the script finishes, should be set as the value of the APPLICATION_VERSION setting.

tell application "Xcode"
	set targetProj to project of active project document
	
	set newVersion to text returned of (display dialog "Enter the new Application Version value:" default answer "")
	
	-- For any build configuration that has an APPLICATION_VERSION build setting, 
	-- change it to the new value.	
	repeat with thisConf in build configurations of targetProj
		try
			set thisVersSetting to build setting "APPLICATION_VERSION" of thisConf
			set value of thisVersSetting to newVersion
		end try
	end repeat
end tell

Fantastic, isn’t it? Of course, nobody wants to fire up Script Editor just to run a script that modifies a build setting in Xcode. That’s what the Script Menu (or the BMW of script menus, FastScripts) is for. From FastScripts, you can even assign an Xcode-specific keyboard shortcut, putting the functionality at your fingertips.

I’ve gotten in the habit of setting up all of my projects with an “APPLICATION_VERSION” build setting in this manner. I drop the above script into my Xcode application-specific scripts folder, and use FastScripts to configure Ctrl-V as an Xcode-specific trigger for running it. This essentially extends Xcode’s functionality for all of my projects such that changing the version on any of my projects is as easy typing Ctrl-V and typing the new string.

I will never have to worry about mismatching version strings again, and I can spit out a newly versioned edition with nary a whimper of tedium. Isn’t silence beautiful?

Update Now that you’ve got your marketing version in order, why not integrate Subversion’s revision number into your bundle version?

This entry was posted to AppleScript, FastScripts, Xcode. Comments are closed. Thanks for reading!