numProperties

The number of indexed properties in this group.For layers, this method returns a value of 3, corresponding to the mask, effect, and motion tracker groups, w

onError

The name of a callback function that is called when an error occurs. By creating a function and assigning it to this attribute, you can respond to errors sy

machineName

The name of the computer on which After Effects is running.String; read-only.

addComp()

Creates a new composition. Creates and returns a new CompItem object and adds it to this collection.If the ItemCollection belongs to the project or the root

replace()

Changes the source of this FootageItem to the specified file. In addition to loading the file, the method creates a new FileSource object for the file and s

parentFolder

The FolderItem object for the folder that contains this item. If this item is at the top level of the project, this is the project’s root folder app.project

addProperty()

Creates and returns a PropertyBase object with the specified name, and adds it to this group.In general, you can only add properties to an indexed group a p

open()

Opens a project.file Optional. An ExtendScript File object for the project file to open. If not supplied, the method prompts the user to select a project fi

osName

The name of the operating system on which After Effects is running.NOTE: As of Windows 7, this attribute returns a blank value. Use $.os instead.String; rea

cuePointName

The Flash Video cue point name, as shown in the Marker dialogbox.String; read/write.