AppleScript

AppleScript is a scripting language created by Apple Inc. that facilitates automated control over scriptable Mac applications. First introduced in System 7, it is currently included in all versions of macOS as part of a package of system automation tools. The term "AppleScript" may refer to the language itself, to an individual script written in the language, or, informally, to the macOS Open Scripting Architecture that underlies the language.

Overview

AppleScript is primarily a scripting language developed by Apple to do inter-application communication (IAC) using Apple events. AppleScript is related to, but different from, Apple events. Apple events are designed to exchange data between and control other applications in order to automate repetitive tasks.

AppleScript has some processing abilities of its own, in addition to sending and receiving Apple events to applications. AppleScript can do basic calculations and text processing, and is extensible, allowing the use of scripting additions that add new functions to the language. Mainly, however, AppleScript relies on the functionality of applications and processes to handle complex tasks. As a structured command language, AppleScript can be compared to Unix shells, the Microsoft Windows Script Host, or IBM REXX but it is distinct from all three. Essential to its functionality is the fact that Macintosh applications publish "dictionaries" of addressable objects and operations.

AppleScript has some elements of procedural programming, object-oriented programming (particularly in the construction of script objects), and natural language programming tendencies in its syntax, but does not strictly conform to any of these programming paradigms.

History

In the late 1980s Apple considered using HyperCard's HyperTalk scripting language as the standard language for end-user development across the company and within its classic Mac OS operating system, and for interprocess communication between Apple and non-Apple products. HyperTalk could be used by novices to program a HyperCard stack. Apple engineers recognized that a similar, but more object-oriented scripting language could be designed to be used with any application, and the AppleScript project was born as a spin-off of a research effort to modernize the Macintosh as a whole and finally became part of System 7.

AppleScript was released in October 1993 as part of System 7.1.1 (System 7 Pro, the first major upgrade to System 7). QuarkXPress (ver. 3.2) was one of the first major software applications that supported AppleScript. This in turn led to AppleScript being widely adopted within the publishing and prepress world, often tying together complex workflows. This was a key factor in retaining the Macintosh's dominant position in publishing and prepress, even after QuarkXpress and other publishing applications were ported to Microsoft Windows.

After some uncertainty about the future of AppleScript on Apple's next generation OS, the move to Mac OS X (around 2002) and its Cocoa frameworks greatly increased the usefulness and flexibility of AppleScript. Cocoa applications allow application developers to implement basic scriptability for their apps with minimal effort, broadening the number of applications that are directly scriptable. At the same time, the shift to the Unix underpinnings and AppleScript's ability to run Unix commands directly, with the do shell script command, allowed AppleScripts much greater control over the operating system itself. AppleScript Studio, released with Mac OS X 10.2 as part of Xcode, and later AppleScriptObjC framework, released in Mac OS X 10.6, allowed users to build Cocoa applications using AppleScript.

In a 2006 article, '' Macworld'' included AppleScript among its rankings of Apple's 30 most significant products to date, placing it at #17.

In a 2013 article for ''Macworld'', veteran Mac software developer and commentator John Gruber concluded his reflection on "the unlikely persistence of AppleScript" by noting: "In theory, AppleScript could be much better; in practice, though, it's the best thing we have that works. It exemplifies the Mac's advantages over iOS for tinkerers and advanced users."

In October 2016, longtime AppleScript product manager and automation evangelist Sal Soghoian left Apple when his position was eliminated "for business reasons". Veterans in the Mac community such as John Gruber and Andy Ihnatko generally responded with concern, questioning Apple's commitment to the developer community and pro users. Apple senior vice president of software engineering Craig Federighi responded in an email saying that "We have every intent to continue our support for the great automation technologies in macOS!", though Jeff Gamet at ''The Mac Observer'' opined that it did little to assuage his doubt about the future of Apple automation in general and AppleScript in particular. For the time being, AppleScript remains one component of macOS automation technologies, along with Automator, Shortcuts, Services, and shell scripting.

Basic concepts

AppleScript was designed to be used as an accessible end-user scripting language, offering users an intelligent mechanism to control applications, and to access and modify data and documents. AppleScript uses Apple events, a set of standardized data formats that the Macintosh operating system uses to send information to applications, roughly analogous to sending XPath queries over XML-RPC in the world of web services. Apple events allow a script to work with multiple applications simultaneously, passing data between them so that complex tasks can be accomplished without human interaction. For example, an AppleScript to create a simple web gallery might do the following:
# Open a photo in a photo-editing application (by sending that application an ''Open File'' Apple event).
# Tell the photo-editing application to manipulate the image (e.g. reduce its resolution, add a border, add a photo credit)
# Tell the photo-editing application to save the changed image in a file in some different folder (by sending that application a ''Save'' and/or ''Close'' Apple event).
# Send the new file path (via another Apple event) to a text editor or web editor application
# Tell that editor application to write a link for the photo into an HTML file.
# Repeat the above steps for an entire folder of images (hundreds or even thousands of photos).
# Upload the HTML file and folder of revised photos to a website, by sending Apple events to a graphical FTP client, by using built-in AppleScript commands, or by sending Apple events to Unix FTP utilities.
For the user, hundreds or thousands of steps in multiple applications have been reduced to the single act of running the script, and the task is accomplished in much less time and with no possibility of random human error. A large complex script could be developed to run only once, while other scripts are used again and again.

An application's scriptable elements are visible in the application's Scripting Dictionary (distributed as part of the application), which can be viewed in any script editor. Elements are generally grouped into ''suites,'' according to loose functional relationships between them. There are two basic kinds of elements present in any suite: classes and commands.
* ''Classes'' are scriptable objects—for example, a text editing application will almost certainly have classes for windows, documents, and texts—and these classes will have properties that can be changed (window size, document background color, text font size, etc.), and may contain other classes (a window will contain one or more documents, a document will contain text, a text object will contain paragraphs and words and characters).
* ''Commands'', by contrast, are instructions that can be given to scriptable objects. The general format for a block of AppleScript is to ''tell'' a scriptable object to run a command.

All scriptable applications share a few basic commands and objects, usually called the Standard Suite—commands to open, close or save a file, to print something, to quit, to set data to variables—as well as a basic ''application'' object that gives the scriptable properties of the application itself. Many applications have numerous suites capable of performing any task the application itself can perform. In exceptional cases, applications may support plugins which include their own scripting dictionaries.

AppleScript was designed with the ability to build scripts intuitively by recording user actions. Such AppleScript recordability has to be engineered into the app—the app must support Apple events and AppleScript recording; as Finder supports AppleScript recording, it can be useful for reference. When AppleScript Editor (Script Editor) is open and the Record button clicked, user actions for recordable apps are converted to their equivalent AppleScript commands and output to the Script Editor window. The resulting script can be saved and re-run to duplicate the original actions, or modified to be more generally useful.

Comments

Comments can be made multiple ways. A one-line comment can begin with 2 hyphens (). In AppleScript 2.0, first released in Mac OS X Leopard, it may also begin with a number sign (#). This permits a self-contained AppleScript script to be stored as an executable text file beginning with the shebang line #!/usr/bin/osascript
Example:

--This is a one line comment
# So is this! (in Mac OS X Leopard or later)

For comments that take up multiple lines, AppleScript uses parentheses with asterisks inside.
Example:

(* This is a
multiple
line
comment *)

Hello, world!

In AppleScript, the traditional