Apple Complaint #8: Disk Images
I used to think that people who complained about Apple’s preferred software distribution mechanism for OS X—the disk image—were all just usability fundamentalists (the kind of people who think the Mac’s glory days ended with OS 9). Then I began distributing my own application, and I realized what a complete usability nightmare the .dmg file can be!
The problem, as I see it, is that most people, when they download software from the Internet, are accustomed to receiving some sort of archive (Zip, StuffIt, Tar or what have you) which decompresses into a folder on their desktop. They then drag the this folder into their Applications folder, where it lives happily.
Unfortunately, as I have discovered, many people try to use this same procedure with disk images, which is a sure recipe for frustration. Earlier today, I received a rather irate email from a customer who was complaining that PodWorks was giving him an error dialog instructing him to “insert the volume” (the understandably brusque subject of his message: “YOU insert the damn volume”).
At first, having only the user’s description of the error to go on, I was a bit befuddled. Upon seeing a screenshot that included a view of his Applications folder, though, it became evident what was going on: he had created a shortcut to the mounted PodWorks disk image and subsequently deleted the original .dmg file.
In this example, I believe the user had made perfectly understandable assumption—he had mistaken the mounted disk image for the decompressed folder or file he was used to seeing after a download. Operating under this assumption, he then dragged it to his Applications folder (an action which evidently—I didn’t realize this until today—creates an alias). After deleting the original .dmg file, he tried to click on what he thought was the PodWorks application and assumed that I was taunting him with an bewilderingly obscure error message.
Until recently, I had always thought of disk images as an elegant concept and a cool way to distribute software. But try explaining how they work (it’s a file that OS X mounts as if it was a disk—get it?) to a non-tecie, and you’re likely to meet with confused looks. In my opinion, they represent a huge usability gaffe on Apple’s part.
To be fair, Apple does seem to have developed a solution in the form of “Internet-enabled disk images” (the ones that spit out a file or folder and then simply disappear). The only problem is, they only work in OS X 10.2.3 or above (although, according to the documentation, making a .dmg Internet-enabled doesn’t interfere with its proper functioning on previous versions of OS X). Regardless, you can be sure I will be Internet-enabling my PodWorks distributions post-haste!