Custom Events

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 user interface.
• 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. You can find the full source for this project on GitHub.

Prerequisites

• The Google Mobile Ads SDK must be integrated into your app to use AdMob to display ads.
• You may also want to read about requesting a banner ad and how Mediation works before proceeding.

Banner custom event

In the following example, you'll first create a banner custom event within AdMob Mediation. This requires defining a custom event that points to that specific class in your app through the AdMob interface, then implementing a CustomEventBanner to serve a view. This example defines a custom event to display ads from the sample ad network, as in the Mediation guide.

Step 1: Define a custom event

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

Here is a screenshot showing some sample custom event settings:

Step 2: Request a banner

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. You can use the parameters provided in this method to make a banner request to your desired network.

Your custom event must notify AdMob 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 lifecycle methods as appropriate. AdMob Mediation forwards the adapter of 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 here.

Here's an example SampleCustomEventBanner.java implementation:

public class SampleCustomEventBanner implements CustomEventBanner {

  /** The {@link 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 it 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 it 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 Mediation.
    // 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;
  }
}

Step 3: Notify AdMob Mediation

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:

You are required to notify AdMob Mediation of all callbacks.

Here's an example SampleCustomBannerEventForwarder.java implementation:

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

    /**
     * Creates a new {@code SampleBannerEventForwarder}.
     * @param listener An AdMob Mediation {@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();
    }
}

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.

Step 1: Define a custom event

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

Step 2: 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 parameters 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.java implementation:

public class SampleCustomEventInterstitial implements CustomEventInterstitial {

  /** Represents a {@link 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 Mediation.
    sampleInterstitial.setAdListener(new SampleCustomInterstitialEventForwarder(listener));

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

  /**
   * Helper method to create a {@link SampleAdRequest}.
   * @param mediationAdRequest The mediation request with targeting information.
   * @return The created {@link 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 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.

Step 3: 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:

public class SampleCustomInterstitialEventForwarder extends SampleAdListener {
    private CustomEventInterstitialListener mInterstitialListener;

    /**
     * Creates a new {@code SampleInterstitialEventForwarder}.
     * @param listener An AdMob Mediation {@link 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();
    }
}

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.