Adobe 27510753 Scripting Guide - Page 22

14 Scripting Basics Adobe InDesign CS2 Scripting Guide for(myCounter = 0; myCounter < app.activeDocument.pages.item(0).pageItems.length; myCounter ++){ var myPageItem = app.activeDocument.pages.item(0).pageItems.item(myCounter); var myPageItemType = myPageItem.getElements()[0].constructor.name; alert(myPageItemType); } Operators Operators use variables or values to perform calculations (addition, subtraction, multiplication, and division) and return a value. For example: MyWidth/2 returns a value equal to half of the content of the variable myWidth. You can also use operators to perform comparisons (equal to (=), not equal to(), greater than(>), or less than( myHeight returns the value true (or 1) if myWidth is greater than myHeight, or false (0), if it isn't. All the scripting languages provide additional utility operators. In AppleScript and VBScript, the ampersand (&) concatenates (or joins) two strings: "Pride " & "and Prejudice" returns the string: "Pride and Prejudice" In JavaScript, use a plus sign (+) to join the two strings: "Pride " + "and Prejudice" //returns the string: "Pride and Prejudice" Methods Methods (sometimes called commands or events) are the verbs of scripting. They're the parts of the script that make more-complex things happen than can be achieved simply by assigning property values. The type of the object you're working with determines the quantity and type of methods that you can use to manipulate the object. In AppleScript, the make command creates new objects, while set assigns values to properties or creates object variables. In VBScript, the Add method creates new objects, the Set statement assigns InDesign objects to VBScript variables, and the equal sign (=) assigns property values (in Visual Basic.NET, you can omit the Set). In JavaScript, the add() method creates new objects, and the equal sign (=) assigns objects to a variable. If you use more than one scripting language, it's easy to get confused as you switch among them. When you're using AppleScript, remember that the equal sign is used only in logical statements (If) and that set is used for all variable assignments. When you're using VBScript or Visual Basic (versions other than VB.NET), Set is used only when you are creating an object variable. In JavaScript, the equal sign is used for assigning values to a variable; use a double equal sign (==) to compare objects. Parameters are sometimes required; for example, when you create a group, InDesign needs to know which objects to include in the new group. Other parameters are optional; for example, when you create a new document, you can specify that InDesign base the new document on a document preset, but it's not required.