// change the position X of all layers with random number

var myComp = app.project.activeItem;
var x = 0;

for (var i = 1; i <= myComp.numLayers; i++) {
  // If you use Math.random(), this does not work
  // x = 400 * (Math.random()) – 200;
  // use new generateRandomNumber() instead

  x = 400 * generateRandomNumber() – 200;
  var currentPos = myComp.layer(i).property("Position").value;
  myComp.layer(i).property("Position").setValue([currentPos[0] + x, currentPos[1]]);
}

var layer = app.project.activeItem.layer(1); // assume layer has three masks
alert(isValid(layer)); // displays "true"
var mask1 = layer.mask(1);
var mask2 = layer.mask(2);
var mask3 = layer.mask(3);
mask3.moveTo(1); // move the third mask to the top of the mask stack
alert(isValid(mask1)); // displays "false"; mask2 and mask3 do as well

write("This text appears in Info panel ");
write("with more on same line.");

writeLn("This text appears on first line");
writeLn("This text appears on second line");

Application object
app
Description
Provides access to objects and application settings within the After Effects application. The single global object is always available by its name, app.
Attributes of the Application object provide access to specific objects within After Effects. Methods of the Application object can create a project, open an existing project, control Watch Folder mode, purge memory, and quit the After Effects application. When the After Effects application quits, it closes the open project, prompting the user to save or discard changes as necessary, and creates a project file as necessary.

Attributes
app.activeViewer
app.activeViewer
Description
The Viewer object for the currently focused or active-focused viewer (Composition, Layer, or Footage) panel. Returns null if no viewers are open.
Type
Viewer object; read-only.

app.availableGPUAccelTypes
app.availableGPUAccelTypes

Note
This functionality was added in After Effects 14.0 (CC 2017)

Description
The Viewer object for the currently focused or active-focused viewer (Composition, Layer, or Footage) panel.
Use this in conjunction with app.project.gpuAccelType to set the value for Project Settings > Video Rendering and Effects > Use.
Type
Array of GpuAccelType enums, or null if no viewers are open; read-only. One of:


CUDA


Metal


OPENCL


SOFTWARE


Example The following sample code checks the current computer’s available GPU acceleration types, and sets it to Metal if available.


// app.availableGPUAccelTypes returns GPU acceleration types available on the current system.
// You can use this to check before setting the GPU acceleration type.
var newType = GpuAccelType.METAL;

// Before trying to set, check which GPU acceleration types are available on the current system.
var canSet = false;
var currentOptions = app.availableGPUAccelTypes;
for (var op in currentOptions) {
    if (currentOptions[op] === newType) {
        canSet = true;
    }
}

if (canSet) {
    // Set the GPU acceleration type.
    app.project.gpuAccelType = newType;
} else {
    alert("Metal is not available on this OS.");
}




app.buildName
app.buildName
Description
The name of the build of After Effects being run, used internally by Adobe for testing and troubleshooting.
Type
String; read-only.

app.buildNumber
app.buildNumber
Description
The number of the build of After Effects being run, used internally by Adobe for testing and troubleshooting.
Type
Integer; read-only.

app.disableRendering
app.disableRendering

Note
This functionality was added in After Effects 16.0 (CC 2019)

Description
When false (the default), rendering proceeds as normal. Set to true to disable rendering as if Caps Lock were turned on.
Type
Boolean; read/write.

app.effects
app.effects
Description
The effects available in the application.
Type
Array, with each element containing the following properties; read-only:


 



displayName


String representing the localized display name of the effect as seen in the Effect menu.




category


String representing the localized category label as seen in the Effect menu. This can be “” for synthetic effects that aren’t normally shown to the user.




matchName


String representing the internal unique name for the effect. This name does not change between versions of After Effects. Use this value to apply the effect.




version


Effect’s internal version string. This value might be different than the version number the plug-in vendor decides to show in the effect’s about box.





Example


var effectName = app.effects[12].displayName;




app.exitAfterLaunchAndEval
app.exitAfterLaunchAndEval
Description
This attribute is used only when executing a script from a command line on Windows. When the application is launched from the command line, the –r or –s command line flag causes the application to run a script (from a file or from a string, respectively). If this attribute is set to true, After Effects will exit after the script is run; if it is false, the application will remain open. This attribute only has an effect when After Effects is run from the Windows command line. It has no effect in Mac OS.
Type
Boolean; read/write.

app.exitCode
app.exitCode
Description
A numeric status code used when executing a script externally (that is, from a command line or AppleScript).


In Windows, the value is returned on the command line when After Effects was launched on the command line (using the afterfx or afterfx –m command), and a script was specified with the –r or –s option.


in Mac OS, the value is returned as the AppleScript DoScript result for each script.


In both Mac OS and Windows, the value is set to 0 (EXIT_SUCCESS) at the beginning of each script evaluation. In the event of an error while the script is running, the script can set this to a positive integer that indicates what error occurred.
Type
Integer; read/write.
Example


app.exitCode = 2; // on quit, if value is 2, an error has occurred




app.isoLanguage
app.isoLanguage
Description
A string indicating the locale (language and regional designations) After Effects is running.

Note
$.locale returns the operating system language, not the language of the After Effects application.

Type
String; read-only. Some common values include:


en_US for English (United States)


de_DE for German (Germany)


es_ES for Spanish (Spain)


fr_FR for French (France)


it_IT for Italian (Italy)


ja_JP for Japanese (Japan)


ko_KR for Korean (Korea)


Example


var lang = app.isoLanguage;
if (lang === "en_US") {
  alert("After Effects is running in English.");
} else if (lang === "fr_FR") {
  alert("After Effects is running in French.");
} else {
  alert("After Effects is running not in English or French.");
}




app.isRenderEngine
app.isRenderEngine
Description
True if After Effects is running as a render engine.
Type
Boolean; read-only.

app.isWatchFolder
app.isWatchFolder
Description
True if the Watch Folder dialog box is currently displayed and the application is currently watching a folder for rendering.
Type
Boolean; read-only.

app.memoryInUse
app.memoryInUse
Description
The number of bytes of memory currently used by this application.
Type
Number; read-only.

app.onError
app.onError
Description
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 systematically; for example, you can close and restart the application, noting the error in a log file if it occurred during rendering. See RenderQueue.render(). The callback function is passed the error string and a severity string. It should not return any value.
Type
A function name string, or null if no function is assigned; read/write.
Example


function err(errString) {
  alert(errString) ;
}
app.onError = err;




app.preferences
app.preferences
Description
The currently loaded AE app preferences. See Preferences object.
Type
Preferences object; read-only.

app.project
app.project
Description
The project that is currently loaded. See Project object.
Type
Project object; read-only.

app.saveProjectOnCrash
app.saveProjectOnCrash
Description
When true (the default), After Effects attempts to display a dialog box that allows you to save the current project if an error causes the application to quit unexpectedly. Set to false to suppress this dialog box and quit without saving.
Type
Boolean; read/write.

app.settings
app.settings
Description
The currently loaded settings. See Settings object.
Type
Settings object; read-only.

app.version
app.version

Note
This functionality was added in After Effects 12.0 (CC)

Description
An alphanumeric string indicating which version of After Effects is running.
Type
String; read-only.
Example


var ver = app.version;
alert("This machine is running version " + ver + " of AfterEffects.");




Methods
app.activate()
app.activate()
Description
Opens the application main window if it is minimized or iconified, and brings it to the front of the desktop.
Parameters
None.
Returns
Nothing.

app.beginSuppressDialogs()
app.beginSuppressDialogs()
Description
Begins suppression of script error dialog boxes in the user interface. Use app.endSuppressDialogs() to resume the display of error dialogs.
Parameters
None.
Returns
Nothing.

app.beginUndoGroup()
app.beginUndoGroup(undoString)
Description
Marks the beginning of an undo group, which allows a script to logically group all of its actions as a single undoable action (for use with the Edit > Undo/Redo menu items). Use the app.endUndoGroup() method to mark the end of the group.
beginUndoGroup() and endUndoGroup() pairs can be nested. Groups within groups become part of the larger group, and will undo correctly. In this case, the names of inner groups are ignored.
Parameters


 



undoString


The text that will appear for the Undo command in the Edit menu (that is, “Undo “)





Returns
Nothing.

app.cancelTask()
app.cancelTask(taskID)
Description
Removes the specified task from the queue of tasks scheduled for delayed execution.
Parameters


 



taskID


An integer that identifies the task, as returned by app.scheduleTask().





Returns
Nothing.

app.endSuppressDialogs()
app.endSuppressDialogs(alert)
Description
Ends the suppression of script error dialog boxes in the user interface. Error dialogs are displayed by default;call this method only if app.beginSuppressDialogs() has previously been called.
Parameters


 



alert


Boolean;


when true, errors that have occurred following the call to beginSuppressDialogs() are displayed in adialog box.





Returns
Nothing.

app.endUndoGroup()
app.endUndoGroup()
Description
Marks the end of an undo group begun with the app.beginUndoGroup() method. You can use this method to place an end to an undo group in the middle of a script, should you wish to use more than one undo group for a single script. If you are using only a single undo group for a given script, you do not need to use this method; in its absence at the end of a script, the system will close the undo group automatically. Calling this method without having set a beginUndoGroup() method yields an error.
Parameters
None.
Returns
Nothing.

app.endWatchFolder()
app.endWatchFolder()
Description
Ends Watch Folder mode.
Parameters
None.
Returns
Nothing.
See also


app.watchFolder()


app.parseSwatchFile()


app.isWatchFolder



app.executeCommand()
app.executeCommand(id)
Description
Menu Commands in the GUI application have an individual ID number, which can be used as the parameter for this method. For some functions not included in the API this is the only way to access them.
The app.findMenuCommandId() method can be used to find the ID number for a command.
These web sites have more information and lists of the known numbers:


https://www.provideocoalition.com/after-effects-menu-command-ids/


https://hyperbrew.co/blog/after-effects-command-ids/


Parameters


 



id


The ID number of the command.





Returns
None.
Example


// calls the Convert to Bezier Path command
app.executeCommand(4162);




app.findMenuCommandId()
app.findMenuCommandId(Command)
Description
Menu Commands in the GUI application have an individual ID number, which can be used as a parameter for the app.executeCommand() command. For some functions not included in the API this is the only way to access them.
It should be noted that this method is not reliable across different language packages of AE, so you’ll likely want to find the command ID number during development and then call it directly using the number in production.
These web sites have more information and lists of the known numbers:


https://www.provideocoalition.com/after-effects-menu-command-ids/


https://hyperbrew.co/blog/after-effects-command-ids/


Parameters


 



Command


The text of the menu command, exactly as it is shown in the UI.





Returns
Integer, the ID number of the menu command.
Example


app.findMenuCommandId("Convert To Bezier Path")




app.newProject()
app.newProject()
Description
Creates a new project in After Effects, replicating the File > New > New Project menu command. If the current project has been edited, the user is prompted to save it. If the user cancels out of the Save dialog box, the new project is not created and the method returns null. Use app.project.close(CloseOptions.DO_NOT_SAVE_CHANGES) to close the current project before opening a new one. See Project.close()
Parameters
None.
Returns
A new Project object, or null if no new project is created.
Example


app.project.close(CloseOptions.DO_NOT_SAVE_CHANGES);
app.newProject();




app.open()

app.open()
app.open(file)

Description
Opens a project.
Parameters


 



file


Optional


An Extendscript File object for the project file to open. If not supplied, the method prompts the user to select a project file.





Returns
A new Project object for the specified project, or null if the user cancels the Open dialog box.
Example


var my_file = new File("../my_folder/my_test.aep");
if (my_file.exists) {
  var new_project = app.open(my_file);
  if (new_project) {
    alert(new_project.file.name);
  }
}




app.parseSwatchFile()
app.parseSwatchFile(file)
Description
Loads color swatch data from an Adobe Swatch Exchange (ASE) file.
Parameters


 



file


The file specification, an Extendscript File object.





Returns
The swatch data, in this format:


 



data.majorVersion data.minorVersion


The ASE version number.




data.values


An array of Swatch Value.




SwatchValue.type


One of “RGB”, “CMYK”, “LAB”, “Gray”




SwatchValue.r
SwatchValue.g SwatchValue.b


When type = "RGB", the color values in the range [0.0..1.0]. 0, 0, 0 is Black.




SwatchValue.c
SwatchValue.m SwatchValue.y SwatchValue.k


When type = “CMYK”, the color values in the range [0.0..1.0]. 0, 0, 0, 0 is White.




SwatchValue.L SwatchValue.a
SwatchValue.b SwatchValue.value


When type = "LAB", the color values. L is in the range [0.0..1.0]. a and b are in the range [-128.0..+128.0] 0, 0, 0 is Black. When type = "Gray", the value range is [0.0..1.0]. 0.0 is Black.






app.pauseWatchFolder()
app.pauseWatchFolder(pause)
Description
Pauses or resumes the search of the target watch folder for items to render.
Parameters


 



pause


True to pause, false to resume.





Returns
Nothing.
See also


app.isWatchFolder


app.watchFolder()


app.endWatchFolder()



app.purge()
app.purge(target)
Description
Purges unused data of the specified types from memory. Replicates the Purge options in the Edit menu.
Parameters


 



target


The type of elements to purge from memory; a PurgeTarget enumerated value, one of:


PurgeTarget.ALL_CACHES: Purges all data that After Effects has cached to physical memory.


PurgeTarget.UNDO_CACHES: Purges all data saved in the undo cache.


PurgeTarget.SNAPSHOT_CACHES: Purges all data cached as composition/layer snapshots.


PurgeTarget.IMAGE_CACHES : Purges all saved image data.







Returns
Nothing.

app.quit()
app.quit()
Description
Quits the After Effects application.
Parameters
None.
Returns
Nothing.

app.scheduleTask()
app.scheduleTask(stringToExecute, delay, repeat)
Description
Schedules the specified JavaScript for delayed execution.
Parameters


 



stringToExecute


A string containing JavaScript to be executed.




delay


A number of milliseconds to wait before executing the JavaScript. A floating-point value.




repeat


When true, execute the script repeatedly, with the specified delay between each execution. When false the script is executed only once.





Returns
Integer, a unique identifier for this task, which can be used to cancel it with app.cancelTask().

app.setMemoryUsageLimits()
app.setMemoryUsageLimits(imageCachePercentage, maximumMemoryPercentage)
Description
Sets memory usage limits as in the Memory & Cache preferences area. For both values, if installed RAM is less than a given amount (n gigabytes), the value is a percentage of the installed RAM, and is otherwise a percentage of n. The value of n is: 2 GB for 32-bit Windows, 4 GB for 64-bit Windows, 3.5 GB for Mac OS.
Parameters


 



imageCachePercentage


Floating-point value, the percentage of memory assigned to image cache.




maximumMemoryPercentage


Floating-point value, the maximum usable percentage of memory.





Returns
Nothing.

app.setMultiFrameRenderingConfig()
app.setMultiFrameRenderingConfig(mfr_on, max_cpu_perc)

Note
This functionality was added in After Effects 22.0 (2022)

Description
Calling this function from a script will set the Multi-Frame Rendering configuration for the next render. After execution of the script is complete, these settings will be reset to what was previously set in the UI.
Parameters


 



mfr_on


Boolean value. Set to true to enable Multi-Frame Rendering.




max_cpu_perc


Value from 1-100 representing the maximum CPU percentage Multi-Frame Rendering should utilize. If mfr_on is set to false, pass in 100.





Returns
Nothing.

app.setSavePreferencesOnQuit()
app.setSavePreferencesOnQuit(doSave)
Description
Set or clears the flag that determines whether preferences are saved when the application is closed.
Parameters


 



doSave


When true, preferences saved on quit, when false they are not.





Returns
Nothing.

app.watchFolder()
app.watchFolder(folder_object_to_watch)
Description
Starts a Watch Folder (network rendering) process pointed at a specified folder.
Parameters


 



folder_object_to_watch


The Folder object for the folder to watch.





Returns
Nothing.
Example


var theFolder = new Folder("c:/tool");
app.watchFolder(theFolder);



See also


app.endWatchFolder()


app.parseSwatchFile()


app.isWatchFolder