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开始使用

前提条件

要集成和测试适用于 Cast 的 PAL SDK，您需要以下各项：

一个接收器应用，用于生成 Nonce：消息拦截。
用于触发接收器加载的发送方应用内容。

由于您只需更新接收器应用即可集成 PAL SDK，可以使用 Cast Command and Control (CAC) 工具以网络发件人身份测试您的接收器。

您可以在每个步骤结束时运行该示例，首先启动您的网站接收器应用工具，然后发出任何加载请求。

生成 Nonce

“Nonce”是由 PAL 通过 NonceManager。通过 NonceManager 由 loadNonceManager NonceLoader 方法中的进行预训练 NonceRequest。要查看使用 PAL 生成 Nonce 的示例应用，请从 GitHub

每个新的视频流请求都需要一个新的 Nonce。将多个广告请求发送到同一个流可以使用相同的 Nonce。如需使用 PAL SDK 生成 Nonce，首先创建自定义网络接收器应用并添加以下代码：

receiver.html

<!DOCTYPE html>
<html>
<head>
  <script src="//www.gstatic.com/cast/sdk/libs/caf_receiver/v3/cast_receiver_framework.js"></script>
  <script src="//imasdk.googleapis.com/pal/sdkloader/cast_pal.js"></script>
</head>
<body>
  <cast-media-player></cast-media-player>
  <footer>
    <script src="js/receiver.js" type="module"></script>
  </footer>
</body>
</html>

<cast-media-player> 元素表示由 Google 提供的 Cast Web Receiver API。根据视频流类型，可能有所不同你可以在 Google Cast 中找到这些播放器的确切版本， SDK 版本说明。

接下来，添加以下代码以拦截 LOAD 事件并在每次接收者每次加载新的 Nonce 时生成一个 Nonce， MediaInformation 对象：

js/receiver.js

const castContext = cast.framework.CastReceiverContext.getInstance();
const playerManager = castContext.getPlayerManager();

const consentSettings = new goog.cast.pal.ConsentSettings();
// For the correct usage of the allowStorage property, See
// developers.google.com/ad-manager/pal/cast/reference/js/ConsentSettings#allowStorage.
consentSettings.allowStorage = true;

// You need a nonce loader to request your stream's nonceManager. The
// nonceManager provides your nonce. You should reuse the same nonce loader for
// the entire lifecycle of the receiver.
const nonceLoader = new goog.cast.pal.NonceLoader(consentSettings);

// You need a reference to the NonceManager to track when an ad is shown or
// clicked.
let nonceManager;

/**
 * Sends a debug message to the CAF sender.
 *
 * @param {String} message - The message to send
 */
const log = (message) => {
  // Use CastDebugLogger to log a message to the sender. See
  // https://developers.google.com/cast/docs/debugging/cast_debug_logger.
}

/**
 * Stores the nonce manager in the outer scoped variable and retrieves a nonce,
 * so it can be used to build your ad request URL
 *
 * @param {NonceManager} loadedNonceManager - The loaded nonce manager
 */
const buildAdRequest = (loadedNonceManager) => {
  nonceManager = loadedNonceManager;

  const nonce = nonceManager.getNonce();
  log('received nonce:' + nonce);

  // TODO: Set this nonce as the value for the `givn` parameter of your ad
  // request URL. For example:
  // const adRequestURL = 'https://myadserver.com/ads?givn=' + nonce;
}

/**
 * Configures a new nonce request, then requests a nonce.
 *
 * @param {LoadRequestData} loadRequestData - the load request object,
 * which contains the MediaInformation object from the sender. See
 * developers.google.com/cast/docs/reference/web_receiver/cast.framework.messages.LoadRequestData
 * @return {(Promise<LoadRequestData>)} - A Promise to build an ad request.
 */
const handleLoadRequest = (loadRequestData) => {
  // Clear any old nonceManager before loading new media.
  nonceManager = null;

  // See developers.google.com/ad-manager/pal/cast/reference/js/NonceRequest
  // for details about each property. The NonceRequest parameters set here are
  // example parameters. You should set your parameters based on your own app
  // characteristics.
  const nonceRequest = new goog.cast.pal.NonceRequest();
  nonceRequest.adWillAutoPlay = true;
  // A URL describing the video stream.
  nonceRequest.descriptionUrl = 'https://example.com';
  nonceRequest.iconsSupported = true;
  nonceRequest.ppid = 'Sample PPID';
  nonceRequest.sessionId = 'Sample SID';
  nonceRequest.url = loadRequestData.media.contentUrl;
  // The height of the player in physical pixels.
  // For a fullscreen player on a 1080p screen, the video height would be 1080.
  nonceRequest.videoHeight = window.devicePixelRatio * window.screen.height;
  // The width of the player in physical pixels.
  // For a fullscreen player on a 1080p screen, the video width would be 1920.
  nonceRequest.videoWidth = window.devicePixelRatio * window.screen.width;

  return nonceLoader.loadNonceManager(nonceRequest)
    .then(buildAdRequest)
    .catch((e) => {
      log("Error: " + e.message);
    });
};

// Set up the event handler for the LOAD event type.
playerManager.setMessageInterceptor(cast.framework.messages.MessageType.LOAD, handleLoadRequest);

castContext.start();

在进行直接 VAST 调用 (DVC) 时，请将此 Nonce 的值设为 givn 参数。Nonce 可在网址中安全使用；则不需要对其进行网址编码

跟踪视频互动

除了生成 Nonce 之外，PAL SDK 还需要在收到视频互动情况要跟踪与 Cast 接收器的互动，请将将以下代码添加到您的自定义接收器中：

js/receiver.js

const castContext = cast.framework.CastReceiverContext.getInstance();
const playerManager = castContext.getPlayerManager();

const consentSettings = new goog.cast.pal.ConsentSettings();
// For the correct usage of the allowStorage property, See
// developers.google.com/ad-manager/pal/cast/reference/js/ConsentSettings#allowStorage.
consentSettings.allowStorage = true;

// You need a nonce loader to request your stream's nonceManager. The
// nonceManager provides your nonce. You should reuse the same nonce loader for
// the entire lifecycle of the receiver.
const nonceLoader = new goog.cast.pal.NonceLoader(consentSettings);

// You need a reference to the NonceManager for sending ad events.
let nonceManager;

// Track playback status.
let playbackDidStart = false;

...

// Register the start of playback.
playerManager.addEventListener(cast.framework.events.EventType.PLAYING, () => {
  if (playbackDidStart) return;

  playbackDidStart = true;
  if (nonceManager) {
    log('Registered playback start');
    nonceManager.sendPlaybackStart();
  } else {
    log("Error: There is no nonce manager for this media.");
  }
});

// Register any interactions with the player.
const interactionEvents = [
  cast.framework.events.EventType.REQUEST_SEEK,
  cast.framework.events.EventType.REQUEST_STOP,
  cast.framework.events.EventType.REQUEST_PAUSE,
  cast.framework.events.EventType.REQUEST_PLAY,
  cast.framework.events.EventType.REQUEST_SKIP_AD,
  cast.framework.events.EventType.REQUEST_PLAY_AGAIN,
  cast.framework.events.EventType.REQUEST_PLAYBACK_RATE_CHANGE,
  cast.framework.events.EventType.REQUEST_VOLUME_CHANGE,
  cast.framework.events.EventType.REQUEST_USER_ACTION,
  cast.framework.events.EventType.REQUEST_FOCUS_STATE,
];
playerManager.addEventListener(interactionEvents, (interactionEvent) => {
  if (nonceManager) {
    log('Registered interaction: ' + interactionEvent);
    nonceManager.sendAdTouch(interactionEvent);
  } else {
    log("Error: There is no nonce manager for this media.");
  }
});

// Register the end of playback.
playerManager.addEventListener(cast.framework.events.EventType.MEDIA_FINISHED, () => {
  playbackDidStart = false;
  if (nonceManager) {
    log('Registered playback end');
    nonceManager.sendPlaybackEnd();
  } else {
    log("Error: There is no nonce manager for this media.");
  }
});

castContext.start();

（可选）通过第三方广告服务器发送 Google Ad Manager 信号

配置第三方广告服务器向 Ad Manager 发出的请求。在您之后完成以下步骤后，Nonce 参数将从 PAL SDK 传播，然后将数据传输到 Google Ad Manager这样一来，通过 Google Ad Manager 获得更高收益

配置您的第三方广告服务器，以在该服务器的向 Ad Manager 发送广告请求下面是在第三方广告服务器：

'https://pubads.serverside.net/gampad/ads?givn=%%custom_key_for_google_nonce%%&...'

有关详情，请参阅 Google Ad Manager 服务器端实施指南。

Ad Manager 会查找 givn= 以标识 Nonce 值。第三方广告服务器需要支持自己的某个宏，例如 %%custom_key_for_google_nonce%%，并将其替换为 Nonce 查询参数您在上一步中提供的 ID。详细了解如何实现这一目标。