This library is intended to be used by any Unity plugin that requires:
- Android specific libraries (e.g AARs).
- iOS CocoaPods.
- Version management of transitive dependencies.
Many Unity plugins have dependencies upon Android specific libraries, iOS CocoaPods, and sometimes have transitive dependencies upon other Unity plugins. This causes the following problems:
- Integrating platform specific (e.g Android and iOS) libraries within a Unity project can be complex and a burden on a Unity plugin maintainer.
- The process of resolving conflicting dependencies on platform specific libraries is pushed to the developer attempting to use a Unity plugin. The developer trying to use you plugin is very likely to give up when faced with Android or iOS specific build errors.
- The process of resolving conflicting Unity plugins (due to shared Unity plugin components) is pushed to the developer attempting to use your Unity plugin. In an effort to resolve conflicts, the developer will very likely attempt to resolve problems by deleting random files in your plugin, report bugs when that doesn't work and finally give up.
The Play Services Resolver plugin (the name comes from its origin of just handling Google Play Services dependencies on Android) provides solutions for each of these problems.
The Android Resolver component of this plugin will download and integrate Android library dependencies and handle any conflicts between plugins that share the same dependencies.
Without the Android Resolver, typically Unity plugins bundle their AAR and
JAR dependencies, e.g. a Unity plugin SomePlugin
that requires the Google
Play Games Android library would redistribute the library and its transitive
dependencies in the folder SomePlugin/Android/
. When a user imports
SomeOtherPlugin
that includes the same libraries (potentially at different
versions) in SomeOtherPlugin/Android/
, the developer using SomePlugin
and
SomeOtherPlugin
will see an error when building for Android that can be hard
to interpret.
Using the Android Resolver to manage Android library dependencies:
- Solves Android library conflicts between plugins.
- Handles all of the various processing steps required to use Android libraries (AARs, JARs) in Unity 4.x and above projects. Almost all versions of Unity have - at best - partial support for AARs.
- (Experimental) Supports minification of included Java components without exporting a project.
The iOS Resolver component of this plugin integrates with CocoaPods to download and integrate iOS libraries and frameworks into the Xcode project Unity generates when building for iOS. Using CocoaPods allows multiple plugins to utilize shared components without forcing developers to fix either duplicate or incompatible versions of libraries included through multiple Unity plugins in their project.
Finally, the Version Handler component of this plugin simplifies the process of managing transitive dependencies of Unity plugins and each plugin's upgrade process.
For example, without the Version Handler plugin, if:
- Unity plugin
SomePlugin
includes thePlay Services Resolver
plugin at version 1.1. - Unity plugin
SomeOtherPlugin
includes thePlay Services Resolver
plugin at version 1.2.
The version of Play Services Resolver
included in the developer's project
depends upon the order the developer imports SomePlugin
or SomeOtherPlugin
.
This results in:
Play Services Resolver
at version 1.2, ifSomePlugin
is imported thenSomeOtherPlugin
is imported.Play Services Resolver
at version 1.1, ifSomeOtherPlugin
is imported thenSomePlugin
is imported.
The Version Handler solves the problem of managing transitive dependencies by:
- Specifying a set of packaging requirements that enable a plugin at different versions to be imported into a Unity project.
- Providing activation logic that selects the latest version of a plugin within a project.
When using the Version Handler to manage Play Services Resolver
included in
SomePlugin
and SomeOtherPlugin
, from the prior example, version 1.2 will
always be the version activated in a developer's Unity project.
Plugin creators are encouraged to adopt this library to ease integration for their customers. For more information about integrating Play Services Resolver into your own plugin, see the Plugin Redistribution section of this document.
The Android Resolver and iOS Resolver components of the plugin only work with Unity version 4.6.8 or higher.
The Version Handler component only works with Unity 5.x or higher as it
depends upon the PluginImporter
UnityEditor API.
Before you import the Play Services Resolver into your plugin project, you first need to consider whether you intend to redistribute Play Services Resolver along with your own plugin.
Redistributing the Play Services Resolver
inside your own plugin will ease
the integration process for your users, by resolving dependency conflicts
between your plugin and other plugins in a user's project.
If you wish to redistribute the Play Services Resolver
inside your plugin,
you must follow these steps when importing the
play-services-resolver-*.unitypackage
, and when exporting your own plugin
package:
- Import the
play-services-resolver-*.unitypackage
into your plugin project by running Unity from the command line, ensuring that you add the-gvh_disable
option. - Export your plugin by running Unity from the command line, ensuring that
you:
- Include the contents of the
Assets/PlayServicesResolver
directory. - Add the
-gvh_disable
option.
- Include the contents of the
You must specify the -gvh_disable
option in order for the Version
Handler to work correctly!
For example, the following command will import the
play-services-resolver-1.2.46.0.unitypackage
into the project
MyPluginProject
and export the entire Assets folder to
MyPlugin.unitypackage
:
Unity -gvh_disable \
-batchmode \
-importPackage play-services-resolver-1.2.46.0.unitypackage \
-projectPath MyPluginProject \
-exportPackage Assets MyPlugin.unitypackage \
-quit
The Version Handler component relies upon deferring the load of editor DLLs
so that it can run first and determine the latest version of a plugin component
to activate. The build of the Play Services Resolver
plugin has Unity asset
metadata that is configured so that the editor components are not
initially enabled when it's imported into a Unity project. To maintain this
configuration when importing the Play Services Resolver
.unitypackage
into a Unity plugin project, you must specify the command line option
-gvh_disable
which will prevent the Version Handler component from running and
changing the Unity asset metadata.
The Android Resolver copies specified dependencies from local or remote Maven repositories into the Unity project when a user selects Android as the build target in the Unity editor.
-
Add the
play-services-resolver-*.unitypackage
to your plugin project (assuming you are developing a plugin). If you are redistributing the Play Services Resolver with your plugin, you must follow the import steps in the Getting Started section! -
Copy and rename the
SampleDependencies.xml
file into your plugin and add the dependencies your plugin requires.The XML file just needs to be under an
Editor
directory and match the name*Dependencies.xml
. For example,MyPlugin/Editor/MyPluginDependencies.xml
. -
Follow the steps in the Getting Started section when you are exporting your plugin package.
For example, to add the Google Play Games library
(com.google.android.gms:play-services-games
package) at version 9.8.0
to
the set of a plugin's Android dependencies:
<dependencies>
<androidPackages>
<androidPackage spec="com.google.android.gms:play-services-games:9.8.0">
<androidSdkPackageIds>
<androidSdkPackageId>extra-google-m2repository</androidSdkPackageId>
</androidSdkPackageIds>
</androidPackage>
</androidPackages>
</dependencies>
The version specification (last component) supports:
- Specific versions e.g
9.8.0
- Partial matches e.g
9.8.+
would match 9.8.0, 9.8.1 etc. choosing the most recent version. - Latest version using
LATEST
or+
. We do not recommend using this unless you're 100% sure the library you depend upon will not break your Unity plugin in future.
The above example specifies the dependency as a component of the Android SDK
manager such that the Android SDK manager will be executed to install the
package if it's not found. If your Android dependency is located on Maven
central it's possible to specify the package simply using the androidPackage
element:
<dependencies>
<androidPackages>
<androidPackage spec="com.google.api-client:google-api-client-android:1.22.0" />
</androidPackages>
</dependencies>
By default the Android Resolver automatically monitors the dependencies you have
specified and the Plugins/Android
folder of your Unity project. The
resolution process runs when the specified dependencies are not present in your
project.
The auto-resolution process can be disabled via the
Assets > Play Services Resolver > Android Resolver > Settings
menu.
Manual resolution can be performed using the following menu options:
Assets > Play Services Resolver > Android Resolver > Resolve
Assets > Play Services Resolver > Android Resolver > Force Resolve
Some AAR files (for example play-services-measurement) contain variables that
are processed by the Android Gradle plugin. Unfortunately, Unity does not
perform the same processing when using Unity's Internal Build System, so the
Android Resolver plugin handles known cases of this variable substition
by exploding the AAR into a folder and replacing ${applicationId}
with the
bundleID
.
Disabling AAR explosion and therefore Android manifest processing can be done
via the Assets > Play Services Resolver > Android Resolver > Settings
menu.
You may want to disable explosion of AARs if you're exporting a project to be
built with Gradle / Android Studio.
Some AAR files contain native libraries (.so files) for each ABI supported by Android. Unfortunately, when targeting a single ABI (e.g x86), Unity does not strip native libraries for unused ABIs. To strip unused ABIs, the Android Resolver plugin explodes an AAR into a folder and removes unused ABIs to reduce the built APK size. Furthermore, if native libraries are not stripped from an APK (e.g you have a mix of Unity's x86 library and some armeabi-v7a libraries) Android may attempt to load the wrong library for the current runtime ABI completely breaking your plugin when targeting some architectures.
AAR explosion and therefore ABI stripping can be disabled via the
Assets > Play Services Resolver > Android Resolver > Settings
menu. You may
want to disable explosion of AARs if you're exporting a project to be built
with Gradle / Android Studio.
By default the Android Resolver will use Gradle to download dependencies prior to integrating them into a Unity project. This works with Unity's internal build system and Gradle / Android Studio project export.
It's possible to change the resolution strategy via the
Assets > Play Services Resolver > Android Resolver > Settings
menu.
The Android Resolver creates the
ProjectSettings/AndroidResolverDependencies.xml
to quickly determine the set
of resolved dependencies in a project. This is used by the auto-resolution
process to only run the expensive resolution process when necessary.
The iOS resolver component of this plugin manages
CocoaPods. A CocoaPods Podfile
is generated and
the pod
tool is executed as a post build process step to add dependencies
to the Xcode project exported by Unity.
Dependencies for iOS are added by referring to CocoaPods.
-
Add the
play-services-resolver-*.unitypackage
to your plugin project (assuming you are developing a plugin). If you are redistributing the Play Services Resolver with your plugin, you must follow the import steps in the Getting Started section! -
Copy and rename the SampleDependencies.xml file into your plugin and add the dependencies your plugin requires.
The XML file just needs to be under an
Editor
directory and match the name*Dependencies.xml
. For example,MyPlugin/Editor/MyPluginDependencies.xml
. -
Follow the steps in the Getting Started section when you are exporting your plugin package.
For example, to add the AdMob pod, version 7.0 or greater with bitcode enabled:
<dependencies>
<iosPods>
<iosPod name="Google-Mobile-Ads-SDK" version="~> 7.0" bitcodeEnabled="true"
minTargetSdk="6.0" />
</iosPods>
</dependencies>
The CocoaPods
are either:
- Downloaded and injected into the Xcode project file directly, rather than
creating a separate xcworkspace. We call this
Xcode project
integration. - If the Unity version supports opening a xcworkspace file, the
pod
tool is used as intended to generate a xcworkspace which references the CocoaPods. We call thisXcode workspace
integration.
The resolution strategy can be changed via the
Assets > Play Services Resolver > Android Resolver > Settings
menu.
The Version Handler component of this plugin manages:
- Shared Unity plugin dependencies.
- Upgrading Unity plugins by cleaning up old files from previous versions.
Unity plugins can be managed by the Version Handler using the following steps:
- Add the
gvh
asset label to each asset (file) you want Version Handler to manage. - Add the
gvh_version-VERSION
label to each asset whereVERSION
is the version of the plugin you're releasing (e.g 1.2.3). - Optional: Add
gvh_targets-editor
label to each editor DLL in your plugin and disableeditor
as a target platform for the DLL. The Version Handler will enable the most recent version of this DLL when the plugin is imported. - Optional: If your plugin is included in other Unity plugins, you should add the version number to each filename and change the GUID of each asset. This allows multiple versions of your plugin to be imported into a Unity project, with the Version Handler component activating only the most recent version.
- Create a manifest text file named
MY_UNIQUE_PLUGIN_NAME_VERSION.txt
that lists all the files in your plugin relative to the project root. Then add thegvh_manifest
label to the asset to indicate this file is a plugin manifest. - Redistribute the
Play Services Resolver
Unity plugin with your plugin. See the Plugin Redistribution for the details.
If you follow these steps:
- When users import a newer version of your plugin, files referenced by the older version's manifest are cleaned up.
- The latest version of the plugin will be selected when users import multiple packages that include your plugin, assuming the steps in Plugin Redistribution are followed.
To build this plugin from source you need the following tools installed:
- Unity (with iOS and Android modules installed)
You can build the plugin by running the following from your shell (Linux / OSX):
./gradlew build && ./gradlew release
or Windows:
./gradlew.bat build && ./gradlew.bat release
The release
target packages the plugin for redistribution:
- Updates
play-services-resolver-*.unitypackage
- Copies the unpacked plugin to the
exploded
directory. - Updates template metadata files in the
plugin
directory.
Each time a new build of this plugin is checked into the source tree you need to do the following:
- Bump the plugin version variable
pluginVersion
inbuild.gradle
- Update
CHANGELOG.md
with the new version number and changes included in the release. git commit --amend -a
to pick up all modified files in the tree. The GUID of all asset metadata is modified due to the version number change. Each file within the plugin is versioned to allow multiple versions of the plugin to be imported into a Unity project which allows the most recent version to be activated by the Version Handler component.