Custom Events for Banner and Interstitial Ads

This guide is intended for publishers looking to use AdMob mediation to do the following:

Show ads from a network that is not directly supported in the AdMob UI.
Show a custom view instead of an ad.

Custom events allow you to write a custom mediation adapter to place any view into your ad space. In this guide, we'll walk through how to write a custom event to request ads from a sample SDK we developed. You can find the full source for the custom event and the corresponding sample SDK on GitHub.

Prerequisites

Before you can integrate custom events for banner or interstitial ads, you need to integrate that ad format into your app. Here are the relevant guides:

Banner custom event

In the following example, you'll first create a banner custom event within AdMob mediation. This requires that you define a custom event that points to that specific class in your app through the AdMob UI, then implement a CustomEventBanner to serve a view. This example defines a custom event to display ads from the sample ad network.

Define a custom event

The custom event must be defined in the AdMob UI. Follow these instructions to create a custom event.

Below is a screenshot showing some sample custom event settings:

Request a banner

To request a banner ad, define a class that implements CustomEventBanner and call it SampleCustomEventBanner. When the custom event is chosen from the ad mediation flow, the requestBannerAd() method is called on the class name you provided in the settings.

The optional parameter defined above is passed into your custom event as part of the requestBannerAd() method. Typically, this parameter is an identifier that enables the custom event to determine which ad to load.

You should also implement lifecycle methods as appropriate. AdMob mediation forwards the adapter onPause() and onResume() activity events if the user calls the AdView.pause() and AdView.resume() methods. The sample ad network doesn't include a pause or resume call, so it provides an empty implementation. Mediation makes its best attempt to call onDestroy() when the adapter is about to be destroyed. Perform any necessary cleanup there.

Here's an example implementation of SampleCustomEventBanner:

Java

public class SampleCustomEventBanner implements CustomEventBanner {

    /** The SampleAdView representing a banner ad. */
    private SampleAdView sampleAdView;

    /** The event is being destroyed. Perform any necessary cleanup here. */
    @Override
    public void onDestroy() {
        if (sampleAdView != null) {
            sampleAdView.destroy();
        }
    }

    /**
     * The app is being paused. This call is only forwarded to the adapter if
     * the developer notifies AdMob mediation that
     * the app is being paused.
     */
    @Override
    public void onPause() {
        // The sample ad network doesn't have an onPause method, so does nothing.
    }

    /**
     * The app is being resumed. This call is only forwarded to the
     * adapter if the developer notifies AdMob
     * mediation that the app is being resumed.
     */
    @Override
    public void onResume() {
        // The sample ad network doesn't have an onResume method, so does nothing.
    }

    @Override
    public void requestBannerAd(Context context,
            CustomEventBannerListener listener,
            String serverParameter,
            AdSize size,
            MediationAdRequest mediationAdRequest,
            Bundle customEventExtras) {

        sampleAdView = new SampleAdView(context);

        // Assumes that the serverParameter is the AdUnit for the Sample Network.
        sampleAdView.setAdUnit(serverParameter);

        sampleAdView.setSize(new SampleAdSize(size.getWidth(), size.getHeight()));

        // Implement a SampleAdListener and forward callbacks to AdMob.
        // The callback forwarding is handled by SampleBannerEventFowarder.
        sampleAdView.setAdListener(new SampleCustomBannerEventForwarder(listener, sampleAdView));

        // Make an ad request.
        sampleAdView.fetchAd(createSampleRequest(mediationAdRequest));

        }

    private SampleAdRequest createSampleRequest(MediationAdRequest mediationAdRequest) {
        SampleAdRequest request = new SampleAdRequest();
        request.setTestMode(mediationAdRequest.isTesting());
        request.setKeywords(mediationAdRequest.getKeywords());
        return request;
        }
}

Kotlin

class SampleCustomEventBanner : CustomEventBanner {

    /** The SampleAdView representing a banner ad. */
    private lateinit var mSampleAdView: SampleAdView

    /** The event is being destroyed. Perform any necessary cleanup here. */
    override fun onDestroy() {
        mSampleAdView.destroy()
    }

    /**
     * The app is being paused. This call is only forwarded to the adapter if
     * the developer notifies AdMob mediation that
     * the app is being paused.
     */
    override fun onPause() {
        // The sample ad network doesn't have an onPause method, so does nothing.
    }

    /**
     * The app is being resumed. This call is only forwarded to the
     * adapter if the developer notifies AdMob
     * mediation that the app is being resumed.
     */
    override fun onResume() {
        // The sample ad network doesn't have an onResume method, so does nothing.
    }

    override fun requestBannerAd(context: Context,
                                 listener: CustomEventBannerListener,
                                 serverParameter: String,
                                 size: AdSize,
                                 mediationAdRequest: MediationAdRequest,
                                 customEventExtras: Bundle?) {

        mSampleAdView = SampleAdView(context)

        // Assumes that the serverParameter is the AdUnit for the Sample Network.
        mSampleAdView.adUnit = serverParameter
        mSampleAdView.size = SampleAdSize(size.width, size.height)

        // Implement a SampleAdListener and forward callbacks to
        // AdMob mediation. The callback forwarding
        // is handled by SampleBannerEventFowarder.
        mSampleAdView.adListener = SampleCustomBannerEventForwarder(listener, mSampleAdView)

        // Make an ad request.
        mSampleAdView.fetchAd(createSampleRequest(mediationAdRequest))
    }

    private fun createSampleRequest(mediationAdRequest: MediationAdRequest): SampleAdRequest {
        val request = SampleAdRequest()
        request.testMode = mediationAdRequest.isTesting
        request.keywords = mediationAdRequest.keywords
        return request
    }
}

The SampleAdView class used in the sample is a simple example of a third-party ad view from the Sample SDK.

Send ad network extras for custom event requests (optional)

If you need to send extra parameters to your custom event, use the addCustomEventExtrasBundle() method of the AdRequest.Builder class. You must pass in your custom event adapter class and a bundle of the extras expected by your custom event adapter.

Here is a code snippet that shows how to pass a SampleExtra parameter for the SampleCustomEventBanner class defined earlier:

Bundle extras = new Bundle();
extras.putBoolean("SampleExtra", true);

AdRequest request = new AdRequest.Builder()
        .addCustomEventExtrasBundle(SampleCustomEventBanner.class, extras)
        .build();

If you don't call addCustomEventExtras() with the correct custom event class and a bundle for a custom event request, the bundle parameter received by the adapter will be null.

Notify AdMob mediation

Your custom event must notify mediation via the CustomEventBannerListener interface when it loads or fails to load an ad. Otherwise, the custom event times out, and ad mediation moves on to the next network.

Implement the ad listener for your network and invoke the relevant callbacks on CustomEventBannerListener to send messages back to AdMob mediation.

We've created the SampleCustomBannerEventForwarder class, implementing the SampleAdListener interface, to forward callbacks from the sample ad network.

AdMob mediation supports the following callbacks:

Banner ads

Method	When to call
`onAdLoaded()`	The banner request succeeded.
`onAdFailedToLoad()`	The banner request failed.
`onAdClicked()`	The banner was clicked.
`onAdOpened()`	The banner is rendering a full-screen view.
`onAdClosed()`	The user returns to the app after clicking on a banner.
`onAdLeftApplication()`	The banner caused the user to leave the app.

Interstitial ads

Method	When to call
`onAdLoaded()`	The interstitial request succeeded.
`onAdFailedToLoad()`	The interstitial request failed.
`onAdClicked()`	The interstitial was clicked.
`onAdOpened()`	The interstitial was shown, rendering a full-screen view.
`onAdClosed()`	The interstitial was closed.
`onAdLeftApplication()`	The interstitial caused the user to leave the app.

Here's an example SampleCustomBannerEventForwarder implementation:

Java

public class SampleCustomBannerEventForwarder extends SampleAdListener {
    private CustomEventBannerListener mBannerListener;
    private SampleAdView mAdView;

    /**
     * Creates a new {@code SampleBannerEventForwarder}.
     * @param listener A {@link CustomEventBannerListener} that should receive
     *                 forwarded events.
     * @param adView   A {@link SampleAdView}.
     */
    public SampleCustomBannerEventForwarder(
            CustomEventBannerListener listener, SampleAdView adView) {
        this.mBannerListener = listener;
        this.mAdView = adView;
    }

    @Override
    public void onAdFetchSucceeded() {
        mBannerListener.onAdLoaded(mAdView);
    }

    @Override
    public void onAdFetchFailed(SampleErrorCode errorCode) {
        switch (errorCode) {
            case UNKNOWN:
                mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INTERNAL_ERROR);
                break;
            case BAD_REQUEST:
                mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INVALID_REQUEST);
                break;
            case NETWORK_ERROR:
                mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NETWORK_ERROR);
                break;
            case NO_INVENTORY:
                mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NO_FILL);
                break;
        }
    }

    @Override
    public void onAdFullScreen() {
        mBannerListener.onAdClicked();
        mBannerListener.onAdOpened();
        // Only call onAdLeftApplication if your ad network actually exits the developer's app.
        mBannerListener.onAdLeftApplication();
    }

    @Override
    public void onAdClosed() {
        mBannerListener.onAdClosed();
    }
}

Kotlin

class SampleCustomBannerEventForwarder(private val mBannerListener: CustomEventBannerListener,
                                       private val mAdView: SampleAdView) : SampleAdListener() {

    override fun onAdFetchSucceeded() {
        mBannerListener.onAdLoaded(mAdView)
    }

    override fun onAdFetchFailed(errorCode: SampleErrorCode) {
        when (errorCode) {
            UNKNOWN -> mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INTERNAL_ERROR)
            BAD_REQUEST -> mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INVALID_REQUEST)
            NETWORK_ERROR -> mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NETWORK_ERROR)
            NO_INVENTORY -> mBannerListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NO_FILL)
        }
    }

    override fun onAdFullScreen() {
        mBannerListener.onAdClicked()
        mBannerListener.onAdOpened()
        // Only call onAdLeftApplication if your ad network actually exits the developer's app.
        mBannerListener.onAdLeftApplication()
    }

    override fun onAdClosed() {
        mBannerListener.onAdClosed()
    }
}

Interstitial custom event

To implement an interstitial custom event, you first create an interstitial custom event within AdMob mediation, much like a banner custom event. Then implement a CustomEventInterstitial to provide notification. This example uses the sample ad network as before.

Define a custom event

You can define an interstitial custom event through the AdMob UI.

Make sure the value you give for the Class Name has a full path. Parameter should contain any information needed to make an ad request to the network you're implementing in the custom event.

Request an interstitial

To request an interstitial, define a class that implements CustomEventInterstitial; we'll call this class SampleCustomEventInterstitial . When the custom event is chosen from the mediation flow, mediation calls the requestInterstitialAd() method on the class name you provided in the settings. You can use the parameter provided in this method to make an interstitial request to your desired network. The following example shows how to request an interstitial from the sample ad network via a custom event:

Here's an example SampleCustomEventInterstitial implementation:

Java

public class SampleCustomEventInterstitial implements CustomEventInterstitial {

    /** Represents a SampleInterstitial. */
    private SampleInterstitial sampleInterstitial;

    @Override
    public void requestInterstitialAd(Context context,
            CustomEventInterstitialListener listener,
            String serverParameter,
            MediationAdRequest mediationAdRequest,
            Bundle customEventExtras) {
        /**
         * In this method, you should:
         * 1. Create your interstitial ad.
         * 2. Set your ad network's listener.
         * 3. Make an ad request.
         */

        sampleInterstitial = new SampleInterstitial(context);

        // Here we're assuming the serverParameter is the ad unit for the sample ad network.
        sampleInterstitial.setAdUnit(serverParameter);

        // Implement a SampleAdListener and forward callbacks to
        // AdMob.
        sampleInterstitial.setAdListener(new SampleCustomInterstitialEventForwarder(listener));

        // Make an ad request.
        sampleInterstitial.fetchAd(createSampleRequest(mediationAdRequest));
    }

    /**
     * Helper method to create a SampleAdRequest.
     * @param mediationAdRequest The mediation request with targeting information.
     * @return The created SampleAdRequest.
     */
    private SampleAdRequest createSampleRequest(MediationAdRequest mediationAdRequest) {
        SampleAdRequest request = new SampleAdRequest();
        request.setTestMode(mediationAdRequest.isTesting());
        request.setKeywords(mediationAdRequest.getKeywords());
        return request;
    }

    @Override
    public void showInterstitial() {
        // Show your interstitial ad.
        sampleInterstitial.show();
    }

    /** The event is being destroyed. Perform any necessary cleanup here. */
    @Override
    public void onDestroy() {
        if (sampleInterstitial != null) {
            sampleInterstitial.destroy();
        }
    }

    /**
     * The app is being paused. This call is only forwarded to the adapter if
     * the developer notifies AdMob mediation
     * that the app is being paused.
     */
    @Override
    public void onPause() {
        // The sample ad network doesn't have an onPause method, so does nothing.
    }

    /**
     * The app is being resumed. This call is only forwarded to the
     * adapter if the developer notifies AdMob
     * mediation that the app is being resumed.
     */
    @Override
    public void onResume() {
        // The sample ad network doesn't have an onResume method, so does nothing.
    }
}

Kotlin

class SampleCustomEventInterstitial : CustomEventInterstitial {

    /** Represents a SampleInterstitial.  */
    private lateinit var mSampleInterstitial: SampleInterstitial

    override fun requestInterstitialAd(context: Context,
                                       listener: CustomEventInterstitialListener,
                                       serverParameter: String,
                                       mediationAdRequest: MediationAdRequest,
                                       customEventExtras: Bundle?) {
        /**
         * In this method, you should:
         * 1. Create your interstitial ad.
         * 2. Set your ad network's listener.
         * 3. Make an ad request.
         */

        mSampleInterstitial = SampleInterstitial(context)

        // Here we're assuming the serverParameter is the ad unit for the sample ad network.
        mSampleInterstitial.adUnit = serverParameter

        // Implement a SampleAdListener and forward callbacks to
        // AdMob mediation.
        mSampleInterstitial.adListener = SampleCustomInterstitialEventForwarder(listener)

        // Make an ad request.
        mSampleInterstitial.fetchAd(createSampleRequest(mediationAdRequest))
    }

    /**
     * Helper method to create a [SampleAdRequest].
     * @param mediationAdRequest The mediation request with targeting information.
     * *
     * @return The created [SampleAdRequest].
     */
    private fun createSampleRequest(mediationAdRequest: MediationAdRequest): SampleAdRequest {
        val request = SampleAdRequest()
        request.testMode = mediationAdRequest.isTesting
        request.keywords = mediationAdRequest.keywords
        return request
    }

    override fun showInterstitial() {
        // Show your interstitial ad.
        mSampleInterstitial.show()
    }


    /** The event is being destroyed. Perform any necessary cleanup here. */
    override fun onDestroy() {
        mSampleInterstitial.destroy()
    }

    /**
     * The app is being paused. This call is only forwarded to the adapter if
     * the developer notifies AdMob mediation that
     * the app is being paused.
     */
    override fun onPause() {
        // The sample ad network doesn't have an onPause method, so does nothing.
    }

    /**
     * The app is being resumed. This call is only forwarded to the adapter if
     * the developer notifies AdMob mediation that
     * the app is being resumed.
     */
    override fun onResume() {
        // The sample ad network doesn't have an onResume method, so does nothing.
    }
}

The interstitial custom event interface requires you to implement the showInterstitial() method. Mediation invokes this method when you tell the Google Mobile Ads SDK to show the interstitial ad.

Send ad network extras for custom event requests (optional)

Here is a code snippet that shows how to pass a "SampleExtra" parameter for the SampleCustomEventInterstitial class defined earlier:

Bundle extras = new Bundle();
extras.putBoolean("SampleExtra", true);

AdRequest request = new AdRequest.Builder()
        .addCustomEventExtrasBundle(SampleCustomEventInterstitial.class, extras)
        .build();

If you don't call addCustomEventExtrasBundle() with the correct custom event class and a bundle for a custom event request, the bundle parameter received by the adapter will be null.

Notify AdMob mediation

Just as with the banner custom event example, implement your network's ad listener to send messages back to AdMob mediation.

This example SampleCustomInterstitialEventForwarder class implements the SampleAdListener interface to forward the callbacks from the sample ad network:

Java

public class SampleCustomInterstitialEventForwarder extends SampleAdListener {
    private CustomEventInterstitialListener mInterstitialListener;

    /**
     * Creates a new SampleInterstitialEventForwarder.
     * @param listener An AdMob CustomEventInterstitialListener that should
     *                 receive forwarded events.
     */
    public SampleCustomInterstitialEventForwarder(CustomEventInterstitialListener listener) {
        this.mInterstitialListener = listener;
    }

    @Override
    public void onAdFetchSucceeded() {
        mInterstitialListener.onAdLoaded();
    }

    @Override
    public void onAdFetchFailed(SampleErrorCode errorCode) {
        switch (errorCode) {
            case UNKNOWN:
                mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INTERNAL_ERROR);
                break;
            case BAD_REQUEST:
                mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INVALID_REQUEST);
                break;
            case NETWORK_ERROR:
                mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NETWORK_ERROR);
                break;
            case NO_INVENTORY:
                mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NO_FILL);
                break;
        }
    }

    @Override
    public void onAdFullScreen() {
        mInterstitialListener.onAdOpened();
        // Only call onAdLeftApplication if your ad network actually exits the developer's app.
        mInterstitialListener.onAdLeftApplication();
    }

    @Override
    public void onAdClosed() {
        mInterstitialListener.onAdClosed();
    }
}

Kotlin

class SampleCustomInterstitialEventForwarder(private val mInterstitialListener: CustomEventInterstitialListener)
        : SampleAdListener() {

    override fun onAdFetchSucceeded() {
        mInterstitialListener.onAdLoaded()
    }

    override fun onAdFetchFailed(errorCode: SampleErrorCode) {
        when (errorCode) {
            UNKNOWN -> mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INTERNAL_ERROR)
            BAD_REQUEST -> mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_INVALID_REQUEST)
            NETWORK_ERROR -> mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NETWORK_ERROR)
            NO_INVENTORY -> mInterstitialListener.onAdFailedToLoad(AdRequest.ERROR_CODE_NO_FILL)
        }
    }

    override fun onAdFullScreen() {
        mInterstitialListener.onAdOpened()
        // Only call onAdLeftApplication if your ad network actually exits the developer's app.
        mInterstitialListener.onAdLeftApplication()
    }

    override fun onAdClosed() {
        mInterstitialListener.onAdClosed()
    }
}

This completes the custom events implementation for interstitial ads. The full example is available on GitHub. You can use it with an ad network that is already supported or modify it to display custom interstitial ads.