Native extension descriptor files

An extension descriptor file describes the contents of a native extension package.

Example extension descriptor

The following extension descriptor document describes a native extension for:

  • an Android device

  • a default ActionScript implementation for other platforms 

<extension xmlns="http://ns.adobe.com/air/extension/3.1"> 
    <id>com.example.MyExtension</id> 
    <versionNumber>0.0.1</versionNumber> 
    <platforms> 
        <platform name="Android-ARM"> 
            <applicationDeployment> 
                <nativeLibrary>MyExtension.jar</nativeLibrary> 
                <initializer>com.sample.ext.MyExtension</initializer> 
            </applicationDeployment> 
        <platform name="default"> 
            <applicationDeployment/> 
        </platform> 
    </platforms> 
</extension>

The extension descriptor file structure

The extension descriptor file is an XML document with the following structure: 

<extension xmlns="http://ns.adobe.com/air/extension/2.5"> 
    <id>...</id> 
    <versionNumber>...</versionNumber> 
    <name> 
        <text xml:lang="language_code">...</text> 
    </name> 
    <description> 
        <text xml:lang="language_code">...</text> 
    </description> 
    <platforms> 
        <platform name="device"> 
            <applicationDeployment> 
                <nativeLibrary>...</nativeLibrary> 
                <initializer>...</initializer> 
                <finalizer>...</finalizer> 
            </applicationDeployment> 
        </platform> 
        <platform name="device"> 
            <deviceDeployment/> 
        <platform name="default"> 
            <applicationDeployment/> 
    </platforms> 
</extension>

Native extension descriptor elements

The following dictionary of elements describes each of the legal elements of an AIR application descriptor file.

applicationDeployment

Declares a native code library included in the extension package and, hence, deployed with the application.

Each platform element must contain either the applicationDeployment element or the deviceDeployment element, but not both.

Parent elements: platform .

Child elements:

Content

Identifies the native code library and the initialization and finalization functions. When the platform name is default , the applicationDeployment element has no child elements because the default platform has no native code libraries.

Example 

<applicationDeployment> 
    <nativeLibrary>myExtension.so</nativeLibrary> 
    <initializer>com.example.extension.Initializer</initializer> 
    <finalizer>com.example.extension.Finalizer</finalizer> 
</applicationDeployment>

copyright

A copyright declaration for the extension.

Parent elements: extension

Child elements: none

Content

A string containing copyright information.

Example 

<copyright>© 2010, Examples, Inc. All rights reserved.</copyright>

description

The description of the extension.

Parent elements: extension

Child elements: text

Content

Use a simple text node or multiple text elements.

Using multiple text elements, you can specify multiple languages in the description element. The xml:lang attribute for each text element specifies a language code, as defined in RFC4646 (http://www.ietf.org/rfc/rfc4646.txt).

Example

Description with simple text node: 

<description>This is a sample native extension for Adobe AIR.</description>

Description with localized text elements for English, French, and Spanish: 

<description> 
    <text xml:lang="en">This is a example.</text> 
    <text xml:lang="fr">C'est un exemple.</text> 
    <text xml:lang="es">Esto es un ejemplo.</text> 
</description>

deviceDeployment

Declares a native extension for which the code libraries are deployed separately on the device and are not included in this extension package.

Device deployment is not supported by all platforms.

Each platform element must contain either the applicationDeployment element or the deviceDeployment element, but not both.

Parent elements: platform

Child elements: None.

Content

None. The deviceDeployment element must be empty.

Example 

<deviceDeployment/>

extension

The root element of the extension descriptor document.

Parent elements: None.

Child elements:

Content

Identifies the supported platforms and the code libraries for each platform.

The extension element contains a namespace attribute called xmlns . Set the xmlns value to one of the following values: 

xmlns="http://ns.adobe.com/air/extension/3.1" 
xmlns="http://ns.adobe.com/air/extension/2.5"

The namespace is one of the factors, along with the SWF version, that determines compatibility between an AIR SDK and an ANE file. The AIR application must be packaged with a version of the AIR SDK that equals or exceeds the extension namespace. Thus an AIR 3 application can use an extension with the 2.5 namespace, but not the 3.1 namespace.

Example 

<extension xmlns="http://ns.adobe.com/air/extension/2.5"> 
    <id>com.example.MyExtension</id> 
    <versionNumber>1.0.1</versionNumber> 
    <platforms> 
        <platform name="Polyphonic-MIPS"> 
            <deviceDeployment/> 
        </platform> 
        <platform name="NeoTech-ARM"> 
            <deviceDeployment/> 
        </platform> 
        <platform name="Philsung-x86"> 
            <deviceDeployment/> 
        </platform> 
        <platform name="default"> 
            <applicationDeployment/> 
        </platform> 
    </platforms> 
</extension>

finalizer

The finalization function defined in the native library.

Parent elements: applicationDeployment

Child elements: None.

Content

The name of the finalizer function if the extension uses the C API in its native library.

If the extension uses the Java API, this element contains the name of the class that implements the FREExtension interface.

The value can contain these characters: A - Z, a - z, 0 - 9, period (.), and dash (-).

Example 

<finalizer>...</finalizer>

id

The ID of the extension.

Parent elements: extension

Child elements: None.

Content

Specifies the ID of the extension.

The value can contain these characters: A - Z, a - z, 0 - 9, period (.), and dash (-).

Example 

<id>com.example.MyExtension</id>

initializer

The initialization function defined in the native library. An initializer element is required if the nativeLibrary element is used.

Parent elements: applicationDeployment

Child elements: None.

Content

The name of the initialization function if the extension uses the C API in its native library.

If the extension uses the Java API, this element contains the name of the class that implements the FREExtension interface.

The value can contain these characters: A - Z, a - z, 0 - 9, period (.), and dash (-).

Example 

<initializer>...</initializer>

name

The name of the extension.

Parent elements: extension

Child elements: text

Content

If you specify a single text node (instead of multiple <text> elements), the AIR application installer uses this name, regardless of the system language.

The xml:lang attribute for each text element specifies a language code, as defined in RFC4646 (http://www.ietf.org/rfc/rfc4646.txt).

Example

The following example defines a name with a simple text node: 

<name>Test Extension</name>

The following example, specifies the name in three languages (English, French, and Spanish) using <text> element nodes: 

<name> 
    <text xml:lang="en">Hello AIR</text> 
    <text xml:lang="fr">Bonjour AIR</text> 
    <text xml:lang="es">Hola AIR</text> 
</name>

nativeLibrary

The native library file included in the extension package for a platform. Consider the following:

  • The nativeLibrary element is not required if the extension contains only ActionScript code.

  • If the nativeLibrary element is not used, the initializer and finalizer elements cannot be used either.

  • If the nativeLibrary element is used, the initializer element is also required.

Parent elements: applicationDeployment

Child elements: None.

Content

The filename of the native library included in the extension package.

The value can contain these characters: A - Z, a - z, 0 - 9, period (.), and dash (-).

Example 

<nativeLibrary>extensioncode.so</nativeLibrary>

platform

Specifies the native code library for the extension on a specific platform.

Parent elements: platforms

Child elements: One, and only one, of the following elements:

Content

The name attribute specifies the name of the platform. The special default platform name allows the extension developer to include an ActionScript library that simulates the behavior of the native code on unsupported platforms. Simulated behavior can be used to support debugging and to provide fall back behavior for multi-platform applications.

Use the following values for the name attribute:

  • Android-ARM for Android devices.

  • default

  • iPhone-ARM for iOS devices.

  • iPhone-x86 for the iOS Simulator.

  • MacOS-x86-64 for Mac OS X devices.

  • QNX-ARM for Blackberry Tablet OS devices.

  • Windows-x86 for Windows devices.

  • appleTV-ARM for tvOS devices.

  • appleTV-x86 for the tvOS Simulator.

Note: Device-bundled extensions use a name attribute value defined by the device manufacturer.

The child elements specify how the native code library is deployed. Application deployment means that the code library is deployed with each AIR application that uses it. The code library must be included in the extension package. Device deployment means that the code library is deployed separately to the platform and is not included in the extension package. The two deployment types are mutually exclusive; include only one deployment element.

Example 

<platform name="Philsung-x86"> 
    <deviceDeployment/> 
</platform> 
<platform name="default"> 
    <applicationDeployment/> 
</platform>

platforms

Specifies the platforms supported by this extension.

Parent elements: extension

Child elements: platform

Content

A platform element for each supported platform. Optionally, a special default platform can be specified containing an ActionScript implementation for use on platforms not supported with a specific code library.

Example 

<platforms> 
    <platform name="Android-ARM"> 
        <applicationDeployment> 
            <nativeLibrary>MyExtension.jar</nativeLibrary> 
            <initializer>com.sample.ext.MyExtension</initializer> 
            <finalizer>com.sample.ext.MyExtension</finalizer> 
        </applicationDeployment> 
    </platform> 
    <platform name="iPhone-ARM"> 
        <applicationDeployment> 
            <nativeLibrary>MyExtension.a</nativeLibrary> 
            <initializer>InitMyExtension></initializer> 
        </applicationDeployment> 
    </platform>
    <platform name="Philsung-x86"> 
        <deviceDeployment/> 
    </platform> 
    <platform name="default"> 
        <applicationDeployment/> 
    </platform> 
    <platform name="appleTV-ARM"> 
        <applicationDeployment>
            <nativeLibrary>MyExtension.a</nativeLibrary>
            <initializer>InitMyExtension></initializer> 
        </applicationDeployment>
    </platform>     
</platforms>

text

Specifies a localized string.

The xml:lang attribute of a text element specifies a language code, as defined in RFC4646 (http://www.ietf.org/rfc/rfc4646.txt).

AIR uses the text element with the xml:lang attribute value that most closely matches the user interface language of the user’s operating system.

For example, consider an installation in which a text element includes a value for the en (English) locale. AIR uses the en name if the operating system identifies en (English) as the user interface language. It also uses the en name if the system user interface language is en-US (U.S. English). However, if the user interface language is en-US and the application descriptor file defines both en-US and en-GB names, then the AIR application installer uses the en-US value.

If the application defines no text element that matches the system user interface languages, AIR uses the first name value defined in the extension descriptor file.

Parent elements:

Child elements: none

Content

An xml:lang attribute specifying a locale and a string of localized text.

Example 

<text xml:lang="fr">Bonjour AIR</text>

versionNumber

The extension version number.

Parent elements: extension

Child elements: none

Content

The version number can contain a sequence of up to three integers separated by periods. Each integer must be a number from 0 to 999 (inclusive).

Examples 

<versionNumber>1.0.657</versionNumber> 
 
<versionNumber>10</versionNumber> 
 
<versionNumber>0.01</versionNumber>

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