4.5 Script Text File

The Script Editor offers the option to save a script as text (or "script text," depending what version of the Script Editor you're using). A script text file is simply a text file, such as can be opened by any word processor. No bytecode is saved into the file. (But the Script Editor does also try to compile the script even when you save it as text, which seems unnecessary.)

A script text file consists of ordinary text in the default system encoding (usually MacRoman). It has file extension .applescript on Mac OS X and is of type 'TEXT' on Mac OS 9 and earlier. The Script Editor saves such a file with both features, and it can be opened on both platforms.

A script text file can be opened with a dedicated editor such as the Script Editor. The situation is then exactly as if you had just typed the code into the Script Editor: if the code is valid and all external referents can be found, the code can be compiled and run.

A script text file cannot generally be run from a script runner application, such as the Script Menu, because the script is not compiled and the application is not prepared to do the compilation for you.

Since a compiled script file can be decompiled and edited further, as well as executed directly, what's the good of a script text file? Apple's documentation implies that it isn't much good, and calls it a "last resort" format; Apple's advice would seem to be that a compiled script file is the standard and most readily usable and communicable format, the format you would use when sending a script to someone else to be run on another machine.

However, I'm not so sure that a compiled script is so very communicable, or that it is better for such purposes than a script text file. There are various formats of compiled script file, and the new ones aren't backward-compatible: a compiled script file saved by the current version of the Script Editor can't be opened by some older versions of the Script Editor, and a compiled script bundle isn't backward-compatible to any system before Mac OS X 10.3 ("Panther"). Plus, as mentioned in the previous section, it is possible for a compiled script to face difficulties with regard to external referents that it can't locate; if these external referents can't be located at all, the script can't even be opened for editing, let alone executed. By contrast, a text file can always be opened under any system and on any machine; AppleScript and the Script Editor are present on every machine, so it is always possible, with valid code, to compile the script afresh.

Not infrequently I have seen AppleScript utterly confused about a reference to an application when a compiled script is moved to a different computer. For example, recently I downloaded from the Internet a compiled script that, when I tried to run it, generated a mysterious error message and didn't work, so I opened it and found references in it to an application that wasn't an application at all (it was just some file buried deep in /usr/share/emacs). Clearly what had happened was that the compiled script had lost track of the application it was supposed to be pointing at, but it was so confused that it didn't even realize this, and instead of asking me for the application's location, had substituted for the name of this application the name of a completely different file. The really devilish part of this situation was that there was no way for me to learn the name of the application the script was really supposed to be pointing to (since the name had been changed in the course of decompilation). Had this script been text, there would have been no difficulty at all, because the name of the application in the text would have been preserved, and I would have been able to compile, save, and execute the script on my own machine without any problem.

(In this regard, a valuable feature of Late Night Software's Script Debugger is that when it saves a compiled script file it also saves the original text into the file, as a TEXT resource. In a pinch, therefore, the text can be recovered and used to help fix problems with external referents.)