AppleScript_ The Definitive Guide - Matt Neuburg [148]
Applications are free to extend AppleScript's vocabulary by implementing constants of their own. For example, GraphicConverter can save an image file in many formats, and it needs a way to let you specify a format; it does this with some four dozen constants, such as PICT, TIFF, GIF, BMP, and JPEG. An application's dictionary will show you the constants that can be used in any connection with a given command. See "Enumerations" in Chapter 20.
Name
true, false
Description
Boolean values. See "Boolean" in Chapter 13 and "Boolean Operators" in Chapter 15.
Example
open for access f write permission true
Name
yes, no, ask
Description
Options when saving a file. For a description of some typical behavior in response to these options, see "Compiled Script Files as Script Objects" in Chapter 8.
Example
store script s in f replacing yes
Name
missing value
Description
This is actually a class, but it has no values; all you'll ever see is the class itself, so it works as if it were a constant. It seems to be a way for an application to return a value while signaling a nonvalue; it isn't an error, and it isn't a failure to return any value at all.
Example
tell application "Finder" to get description of folder 1 -- missing value
Name
null
Description
Like missing value, this is implemented as a class with no values. I've never found a use for it in communicating with a scriptable application, nor have I ever seen an application return it as a result. But I do sometimes use it in my own scripts, as a way of giving a variable or record item a value that signifies "No value has been assigned yet" without its being undefined. Examples have appeared in "The Run Handler" in Chapter 9 and "Record" in Chapter 13.
Example
set aPerson to {name:null, age:null, town:null}
Name
plain, bold, italic, outline, shadow, underline, superscript, subscript, strikethrough, small caps, all caps, all lowercase, condensed, expanded, hidden
Description
Text styles, for applications that wish to speak of such things. The example here shows Tex-Edit Plus returning a text style record. (See "Records" in Chapter 20.) This is a record consisting of two lists, the on styles (those that are applied to a piece of text) and the off styles (those that are not applied to a piece of text). The items of each list are text styles. The piece of text we're asking about here is underlined.
Example
tell application "Tex-Edit Plus"
set tsr to style of word 4 of document 1
on styles of tsr -- {underline}
end tell
Name
case, diacriticals, white space, hyphens, expansion, punctuation, numeric strings
Description
String considerations ; see "Considering/Ignoring" in Chapter 19.
Example
considering case
"heyho" contains "H" -- false
end considering
Name
application responses
Description
See "Considering/Ignoring" in Chapter 19.
Example
ignoring application responses
tell application "GraphicConverter" to quit
end ignoring
Name
current application
Description
The top-level object. See "The Implicit Parent Chain" in Chapter 8.
Example
name of
current application -- Script Editor
Name
Sunday, Monday, Tuesday, Wednesday, Thursday, Friday, Saturday
Description
Days of the week; see "Date Properties" in Chapter 13. These terms are actually implemented as class names (I don't know why).
Example
weekday of (current date) -- Wednesday
Name
January, February, March, April, May, June, July, August, September, October, November, December
Description
Names of months; see "Date Properties" in Chapter 13. These terms are actually implemented as class names (I don't know why).
Example
month of (current date) -- May
Chapter 18. Commands
A command is basically a verb. Technically, a command is called an event (because it really is an Apple event, as discussed in Chapter