Google Consent Mode

Google Consent Mode enables web and app developers to modify the behavior of Google tags and SDKs based on users' consent preferences. When implemented, it allows Google services such as Google Analytics, Google Ads, Floodlight, and Conversion Linker to dynamically adjust their functionality in response to consent signals. This is achieved through defined consent types, which control specific aspects of how each product behaves depending on the user's choices.

Consent types include:

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For more information, see Google's documentation here: About consent mode.

Setting up Google Consent Mode (GCM) for iOS/tvOS

1. Enable Google Consent Mode in your geolocation rules and map categories from the OneTrust CMP to Google storage types.
   1. 
2. Ensure the supported Google products (e.g. Firebase) have been installed on the app already.
3. Set the default consent values for GCM in your app's info.plist. Value can be set to true or false.
   Text

   <key>GOOGLE_ANALYTICS_DEFAULT_ALLOW_ANALYTICS_STORAGE</key> <false/>
   <key>GOOGLE_ANALYTICS_DEFAULT_ALLOW_AD_STORAGE</key> <false/>
   <key>GOOGLE_ANALYTICS_DEFAULT_ALLOW_AD_USER_DATA</key> <false/>
   <key>GOOGLE_ANALYTICS_DEFAULT_ALLOW_AD_PERSONALIZATION_SIGNALS</key> <false/>
   

   1. 

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Decision Point

For SDK versions 202512.1.0+, see this section for next steps.

For SDK versions <202512.1.0, continue with the steps below.

4. Query for Google Consent Mode consent statuses from the OneTrust SDK. getOTGoogleConsentModeData() will return an object containing the current status and values for each of the Google Consent types based on the mapping done in Step 1.

OTPublishersHeadlessSDK.shared.getOTGoogleConsentModeData().otSDKStatus
OTPublishersHeadlessSDK.shared.getOTGoogleConsentModeData().consentType

Sample Response

//consent interaction status
OneTrust GCM SDK status: consented

//consent value of each storage type
OTGoogleConsentType(
  analyticsStorage: OTPublishersHeadlessSDK.OTGoogleConsentMode.granted, 
  adStorage: OTPublishersHeadlessSDK.OTGoogleConsentMode.granted, 
  adUserData: OTPublishersHeadlessSDK.OTGoogleConsentMode.granted, 
  adPersonalization: OTPublishersHeadlessSDK.OTGoogleConsentMode.granted)

5. Update the desired Google library from the consent retrieved in Step 4 with the setConsent() public method from Google.

Analytics.setConsent([
.analyticsStorage: .granted,
.adStorage: .granted,
.adUserData: .granted,
.adPersonalization: .granted,
])

As the application will need to retrieve the consents for each Consent type and set it in the Google library as indicated in steps 4 and 5, OneTrust has written a function to assist with and simplify the process:

1. Swift

   func handleGoogleConsentMode() {
       let gcmOTData = OTPublishersHeadlessSDK.shared.getOTGoogleConsentModeData()
       #if canImport(FirebaseAnalytics)
       Analytics.setConsent([
           .adStorage: gcmOTData.consentType.adStorage == .granted ? .granted : .denied,
           .analyticsStorage: gcmOTData.consentType.analyticsStorage == .granted ? .granted : .denied,
           .adUserData: gcmOTData.consentType.adUserData == .granted ? .granted : .denied,
           .adPersonalization: gcmOTData.consentType.adPersonalization == .granted ? .granted : .denied,
       ])
       #endif
   }
   

2. OneTrust recommends calling the handleGoogleConsentMode() function above when the OTConsentUpdated broadcast is triggered. OTConsentUpdated is triggered every time any OneTrust UI is dismissed. More info on that method here .

   Swift

   NotificationCenter.default.addObserver(self,
       selector: #selector(returnConsentOTConsentUpdated(_:)),
       name: Notification.Name("OTConsentUpdated"),
       object: nil)
   
   @objc func returnConsentOTConsentUpdated(_ notification:Notification){
       handleGoogleConsentMode()
   }
   

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For more information regarding consent mode setup, see: Set up consent mode for apps.

202512.1.0+ SDK

As of 202512.1.0, the OneTrust SDK automatically synchronizes user consent preferences with the Firebase Analytics SDK without additional code from the app.

1. Complete Steps 1 - 3 above
2. Add -ObjC into your app target's Other Linker Flags. This ensures Firebase classes are retained in memory and accessible by the OneTrust SDK.
3. (Optional) Enable Firebase Analytics debug logging by adding the following arguments to your app’s scheme: -FIRAnalyticsVerboseLoggingEnabled and -FIRAnalyticsDebugEnabled. These flags help print Firebase Analytics logs for troubleshooting.

Once the setup is complete, the OneTrust SDK will:

• Detect if Firebase is present in the app
• Automatically invoke setConsent() for each supported and mapped consent type

For details on the setConsent() method, refer to Google’s documentation.

Verifying consent settings

You can verify that your consent settings are working as intended by viewing the Xcode debug console for your app.

1. Enable verbose logging on your device.

2. In the Xcode debug console, look for:

   • analytics_storage
   • ad_storage
   • ad_user_data
   • ad_personalization

   For example, if Ad storage are enabled, you'll see the following message:

   ad_storage is granted.
   

Google Consent Mode for IAB TCF

Applications can be configured to instruct Google to interpret the IAB TC String in order to determine consent values for the following Consent Mode settings:

In the OneTrust platform, enable the Google Consent Mode toggle in geolocation rules using the IAB TCF template. When this configuration is enabled, the SDK will write the key IABTCF_EnableAdvertiserConsentMode to local storage and allows Google to automatically adjust its signal behavior according to TC String consents.

Google Consent Mode storage types are mapped to TCF purposes as follows:

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For more information about IAB TCF integration behavior with GCM, see Google's documentation Enable consent mode TCF integration.