AIR applications are distributed via AIR installer files which use the air extension. When the AIR runtime is installed and an AIR installer file is opened, the runtime administers the installation process.

Contents

• AIR runtime installation location
• Seamless install (runtime and application)
• Manual install
• Application installation flow
• Application destination
• The AIR file system
• AIR application storage
• Updating Adobe AIR
• Updating AIR applications
• Uninstalling an AIR application
• Uninstalling Adobe AIR
• Windows registry settings for administrators

AIR runtime installation location

AIR applications first require the AIR runtime to be installed on a user's computer, just as SWF files first require the Flash Player browser plug-in to be installed.

The runtime is installed to the following location on a user's computer:

• Mac OS: /Library/Frameworks/
• Windows: C:\Program Files\Common Files\Adobe AI

On Mac OS, to install an updated version of an application, the user needs to have adequate system privileges to install to the application directory. On Windows, a user needs to have adminstrative privileges.

The runtime can be installed in two ways: using the seamless install feature (installing directly from a web browser) or via a manual install. For more information, see Distributing, Installing, and Running AIR applications.

Seamless install (runtime and application)

The seamless install feature provides developers with a streamlined installation experience for users who do not have Adobe AIR installed yet. In the seamless install method, the developer creates a SWF file that presents the application for installation. When a user clicks in the SWF file to install the application, the SWF file attempts to detect the runtime. If the runtime cannot be detected it is installed, and the runtime is activated immediately with the installation process for the developer's application.

Manual install

Alternatively, the user can manually download and install the runtime before opening an AIR file. The developer can then distribute an AIR file by different means (for instance, via e-mail or an HTML link on a website). When the AIR file is opened, the runtime begins to process the application installation.

For more information on this process, see Distributing, Installing, and Running AIR applications.

Application installation flow

The AIR security model allows users to decide whether to install an AIR application. The AIR install experience provides several improvements over native application install technologies that make this trust decision easier for users:

• The AIR runtime provides a consistent installation experience on all operating systems, even when an AIR application is installed from a link in a web browser. Most native application install experiences depend upon the browser or other application to provide security information, if it is provided at all.
• The AIR application install experience identifies the source of the application and information about what privileges will be available to the application (if the user allows the installation to proceed).
• The AIR runtime administers the installation process of an AIR application. An AIR application cannot manipulate the installation process the AIR runtime uses.

In general, users should not install any desktop application that comes from a source that they do not trust, or that cannot be verified. The burden of proof on security for native applications is equally true for AIR applications as it is for other installable applications.

Application destination

The installation directory can be set using one of the following two options:

1. The user customizes the destination during installation. The application installs to wherever the user specifies.
2. If the user does not change the install destination, the application installs to the default path as determined by the runtime:

• Mac OS: ~/Applications/
• Windows XP and earlier: C:\Program Files\
• Windows Vista: ~/Apps/

If the developer specifies an installFolder setting in the application descriptor file, the application is installed to a subpath of this directory.

The AIR file system

The install process for AIR applications copies all files that the developer has included within the AIR installer file onto the user's local machine. The installed application is composed of:

• Windows: A directory containing all files included in the AIR installer file. The AIR runtime also creates an exe file during the installation of the AIR application.
• Mac OS: An app file that contains all of the contents of the AIR installer file. It can be inspected using the "Show Package Contents" option in Finder. The AIR runtime creates this app file as part of the installation of the AIR application.

An AIR application is run by:

• Windows: Running the .exe file in the install folder, or a shortcut that corresponds to this file (such as a shortcut on the Start Menu or desktop)
• Mac OS: Running the .app file or an alias that points to it.

The application file system also includes subdirectories related to the function of the application. For example, information written to encrypted local storage is saved to a subdirectory in a directory named after the application identifier (appId) of the application.

AIR application storage

AIR applications have privileges to write to any location on the user's hard drive; however, developers are encouraged to use the app-storage:/ path for local storage related to their application. Files written to app-storage:/ from an application are located in a standard location depending on the user's operating system:

• On Mac OS: the storage directory of an application is <appData>/<appId>/Local Store/ where <appData> is the user's "preferences folder," typically /Users/<user>/Library/Preferences
• On Windows: the storage directory of an application is <appData>\<appId>\Local Store\ where <appData> is the user's CSIDL_APPDATA "Special Folder" typically C:\Documents and Settings\<userName>\Application Data

You can access the application storage directory via the air.File.applicationStorageDirectory property. You can access its contents using the resolvePath() method of the File class. For details, see Working with the file system.

Updating Adobe AIR

When the user installs an AIR application that requires an updated version of the AIR runtime, the AIR runtime automatically installs the required runtime update.

To update the runtime, a user needs to have administrative privileges for the computer.

Updating AIR applications

Development and deployment of software updates are one of the biggest security challenges facing native code applications. The AIR API provides a mechanism to improve this: the Updater.update() method can be invoked upon launch to check a remote location for an AIR file. If an update is appropriate, the AIR file is downloaded, installed, and the application restarts. Developers can use this class not only to provide new functionality but also respond to potential security vulnerabilities.

Uninstalling an AIR application

A user can uninstall an AIR application:

• On Windows: Using the Add/Remove Programs panel to remove the application.
• On Mac OS: Deleting the app file from the install location.

Removing an AIR application removes all files in the application directory. However, it does not remove files that the application may have written to outside of the application directory. Removing AIR applications does not revert changes the AIR application has made to files outside of the application directory.

Uninstalling Adobe AIR

AIR can be uninstalled:

• On Windows: by running Add/Remove Programs from the Control Panel, selecting Adobe AIR and selecting "Remove"
• On Mac OS: by running the Adobe AIR Uninstaller application in the Applications directory.

Windows registry settings for administrators

On Windows, administrators can configure a machine to prevent (or allow) AIR application installation and runtime updates. These settings are contained in the Windows registry under the following key: HKLM\Software\Policies\Adobe\AIR. They include the following: