This guide describes how to support in-app updates in your app using Unreal Engine. There are separate guides for cases where your implementation uses the Kotlin programming language or the Java programming language, and cases where your implementation uses native code (C/C++) or Unity.
Unreal Engine SDK overview
The Play In-App Updates API is part of Play Core SDK family. The API for Unreal
Engine offers a UInAppUpdatesManager class to handle communication between
your app and the Play API. After a request is made, your app can check the
status of the request using EAppUpdateErrorCode.
Supported Unreal Engine versions
The plugin supports Unreal Engine 5.0 and all subsequent versions.
Set up your development environment
Download the Play Unreal Engine Plugin from the GitHub repository.
Copy the
GooglePlayfolder inside yourPluginsfolder in your Unreal Engine project.Open your Unreal Engine project and click Edit → Plugins.
Search for Google Play and check the Enabled checkbox.
Restart the game project and trigger a build.
Open your project's
Build.csfile and add thePlayInAppUpdatesmodule toPublicDependencyModuleNames:using UnrealBuildTool; public class MyGame : ModuleRules { public MyGame(ReadOnlyTargetRules Target) : base(Target) { // ... PublicDependencyModuleNames.Add("PlayInAppUpdates"); // ... } }
Check for update availability
Before you request an update, check if there is an update available for your
app. Use UInAppUpdatesManager::RequestInfo to check for an update:
MyClass.h
void MyClass::OnRequestInfoOperationCompleted(
EAppUpdateErrorCode ErrorCode,
UAppUpdateInfo* UpdateInfo)
{
// Check the resulting error code.
if (ErrorCode == EAppUpdateErrorCode::AppUpdate_NO_ERROR)
{
// Check AppUpdateInfo's UpdateAvailability, UpdatePriority,
// IsUpdateTypeAllowed(), ... and decide whether to ask the user
// to start an in-app update.
}
}
MyClass.cpp
void MyClass::CheckForUpdateAvailability()
{
// Create a delegate to bind the callback function.
FRequestInfoOperationCompletedDelegate Delegate;
// Bind the completion handler (OnRequestInfoOperationCompleted) to the delegate.
Delegate.BindDynamic(this, &MyClass::OnRequestInfoOperationCompleted);
// Initiate the request info operation, passing the delegate to handle the result.
GetGameInstance()
->GetSubsystem<UInAppUpdatesManager>()
->RequestInfo(Delegate);
}
The returned UAppUpdateInfo instance contains the update availability status.
If an in-app update is already in progress, the instance also reports the status
of the in-progress update.
Check update staleness
In addition to checking whether an update is available, you might also want to check how much time has passed since the user was last notified of an update through the Play Store. This can help you decide whether you should initiate a flexible update or an immediate update. For example, you might wait a few days before notifying the user with a flexible update, and a few days after that before requiring an immediate update.
Use UAppUpdateInfo:GetClientVersionStalenessDays to check the number of days
since the update became available through the Play Store:
int32 ClientVersionStalenessDays = UpdateInfo->GetClientVersionStalenessDays();
Check update priority
The Google Play Developer API lets you set the priority of each update. This allows your app to decide how strongly to recommend an update to the user. For example, consider the following strategy for setting update priority:
- Minor UI improvements: Low-priority update; request neither a flexible update nor an immediate update.
- Performance improvements: Medium-priority update; request a flexible update.
- Critical security update: High-priority update; request an immediate update.
To determine priority, Google Play uses an integer value between 0 and 5, with 0
being the default and 5 being the highest priority. To set the priority for an
update, use the inAppUpdatePriority field under Edits.tracks.releases in the
Google Play Developer API. All newly-added versions in the release are
considered to be the same priority as the release. Priority can only be set when
rolling out a new release and cannot be changed later.
Set the priority using the Google Play Developer API as described in the Play
Developer API documentation. In-app update priority should be specified in
the Edit.tracks resource passed in the Edit.tracks: update method.
The following example demonstrates releasing an app with version code 88 and
inAppUpdatePriority 5:
{ "releases": [{ "versionCodes": ["88"], "inAppUpdatePriority": 5, "status": "completed" }] }
In your app's code, you can check the priority level for a given update using
UAppUpdateInfo::UpdatePriority:
int32 Priority = UpdateInfo->GetPriority();
Start an update
After you confirm that an update is available, you can request an update using
UInAppUpdatesManager::StartUpdate. Before you request an update, make sure
that you have an up-to-date UAppUpdateInfo object. You must also create an
UAppUpdateOptions object to configure the update flow.
The following example creates an UAppUpdateOptions object for an immediate
update flow:
// Creates an UAppUpdateOptions defining an immediate in-app
// update flow and its parameters.
UAppUpdateOptions* Options = NewObject<UAppUpdateOptions>();
Options->CreateOptions(EAppUpdateType::AppUpdate_TYPE_IMMEDIATE);
The following example creates an UAppUpdateOptions object for a flexible
update flow:
// Creates an UAppUpdateOptions defining a flexible in-app
// update flow and its parameters.
UAppUpdateOptions* Options = NewObject<UAppUpdateOptions>();
Options->CreateOptions(EAppUpdateType::AppUpdate_TYPE_FLEXIBLE);
The UAppUpdateOptions object also contains an IsAssetPackDeletionAllowed
function that returns whether the update is allowed to clear asset packs in
case of limited device storage. This field is set to false by default, but you
can set the field using UAppUpdateOptions::SetAssetPackDeletionAllowed to set
it to true instead:
// Sets the AssetPackDeletionAllowed field to true.
Options->SetAssetPackDeletionAllowed(true);
The next steps depend on whether you are requesting a flexible update or an immediate update.
Handle a flexible update
After you have an up-to-date UAppUpdateInfo object and a properly-configured
UAppUpdateOptions object, you can call UInAppUpdatesManager::StartUpdate to
request an update flow.
MyClass.h
void MyClass::OnStartUpdateOperationCompleted(EAppUpdateErrorCode ErrorCode)
{
// ...
}
MyClass.cpp
// .cpp
void MyClass::StartUpdate()
{
// Create a delegate to bind the callback function.
FUpdateOperationCompletedDelegate Delegate;
// Bind the completion handler (OnStartUpdateOperationCompleted) to the delegate.
Delegate.BindDynamic(this, &MyClass::OnStartUpdateOperationCompleted);
// Initiate the start update operation, passing the delegate to handle the result.
GetGameInstance()
->GetSubsystem<UInAppUpdatesManager>()
->StartUpdate(UpdateInfo, UpdateOptions, Delegate);
}
For a flexible update flow, you must trigger the installation of the app update
after the download finishes successfully. To do this, call
InAppUpdatesManager::CompleteUpdate, as shown in the following example:
MyClass.h
void MyClass::OnCompleteUpdateOperationCompleted(EAppUpdateErrorCode ErrorCode)
{
// ...
}
MyClass.cpp
void MyClass::CompleteFlexibleUpdate()
{
// Create a delegate to bind the callback function.
FUpdateOperationCompletedDelegate Delegate;
// Bind the completion handler (OnCompleteUpdateOperationCompleted) to the delegate.
Delegate.BindDynamic(this, &MyClass::OnCompleteUpdateOperationCompleted);
// Initiate the complete update operation, passing the delegate to handle the result.
GetGameInstance()
->GetSubsystem<UInAppUpdatesManager>()
->CompleteUpdate(UpdateInfo, UpdateOptions, Delegate);
}
Handle an immediate update
After you have an up-to-date UAppUpdateInfo object and a properly-configured
UAppUpdateOptions object, you can call InAppUpdatesManager::StartUpdate to
request an update flow.
MyClass.h
void MyClass::OnStartUpdateOperationCompleted(EAppUpdateErrorCode ErrorCode)
{
// ...
}
MyClass.cpp
void MyClass::StartUpdate()
{
// Create a delegate to bind the callback function.
FUpdateOperationCompletedDelegate Delegate;
// Bind the completion handler (OnStartUpdateOperationCompleted) to the delegate.
Delegate.BindDynamic(this, &MyClass::OnStartUpdateOperationCompleted);
// Initiate the start update operation, passing the delegate to handle the result.
GetGameInstance()
->GetSubsystem<UInAppUpdatesManager>()
->StartUpdate(UpdateInfo, UpdateOptions, Delegate);
}
For an immediate update flow, Google Play displays a user confirmation dialog. When the user accepts the request, Google Play automatically downloads and installs the update, then restarts the app to the updated version if installation is successful.
Error handling
This section describes solutions for common errors.
- If
UInAppUpdatesManager::StartUpdatereturns anAppUpdate_INVALID_REQUESTerror, it means thatUAppUpdateInfois invalid. Make sure theUAppUpdateInfoobject returned fromUInAppUpdatesManager::RequestInfois not null before starting the update flow. - If
UInAppUpdatesManager::StartUpdatereturns theAppUpdate_NOT_ALLOWEDerror, it means that theUAppUpdateOptionsobject indicates an update type that is not allowed for the available update. Check whether theUAppUpdateInfoobject indicates that the selected update type is allowed before starting the update flow.
Next steps
Test your app's in-app updates to verify that your integration is working correctly.