From 64e537367a569750d7a0d210521c77b288890ff7 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?/z=C9=92=CC=83ge/?= <zangue@users.noreply.github.com>
Date: Wed, 26 Apr 2023 00:30:33 +0200
Subject: [PATCH] docs: update `config.drm.initDataTransform` documentation
 (#5170)

---
 docs/tutorials/fairplay.md |  4 ++--
 externs/shaka/player.js    | 20 +++++++++++++-------
 2 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/docs/tutorials/fairplay.md b/docs/tutorials/fairplay.md
index 7ca3f7439c..dac5b29c0b 100644
--- a/docs/tutorials/fairplay.md
+++ b/docs/tutorials/fairplay.md
@@ -25,14 +25,14 @@ is used by the browser to generate the license request.  If you don't use the
 default content ID derivation, you need to specify a custom init data transform:
 
 ```js
-player.configure('drm.initDataTransform', (initData, initDataType) => {
+player.configure('drm.initDataTransform', (initData, initDataType, drmInfo) => {
   if (initDataType != 'skd')
     return initData;
 
   // 'initData' is a buffer containing an 'skd://' URL as a UTF-8 string.
   const skdUri = shaka.util.StringUtils.fromBytesAutoDetect(initData);
   const contentId = getMyContentId(skdUri);
-  const cert = player.drmInfo().serverCertificate;
+  const cert = drmInfo.serverCertificate;
   return shaka.util.FairPlayUtils.initDataTransform(initData, contentId, cert);
 });
 ```
diff --git a/externs/shaka/player.js b/externs/shaka/player.js
index 2f06c9907d..93350fdd46 100644
--- a/externs/shaka/player.js
+++ b/externs/shaka/player.js
@@ -613,9 +613,7 @@ shaka.extern.AdvancedDrmConfiguration;
  *   clearKeys: !Object.<string, string>,
  *   delayLicenseRequestUntilPlayed: boolean,
  *   advanced: Object.<string, shaka.extern.AdvancedDrmConfiguration>,
- *   initDataTransform:
- *       ((function(!Uint8Array, string, ?shaka.extern.DrmInfo):!Uint8Array)|
- *         undefined),
+ *   initDataTransform:(shaka.extern.InitDataTransform|undefined),
  *   logLicenseExchange: boolean,
  *   updateExpirationTime: number,
  *   preferredKeySystems: !Array.<string>
@@ -639,10 +637,7 @@ shaka.extern.AdvancedDrmConfiguration;
  *   <i>Optional.</i> <br>
  *   A dictionary which maps key system IDs to advanced DRM configuration for
  *   those key systems.
- * @property
- *     {((function(!Uint8Array, string, ?shaka.extern.DrmInfo):!Uint8Array)|
- *        undefined)}
- *   initDataTransform
+ * @property {shaka.extern.InitDataTransform|undefined} initDataTransform
  *   <i>Optional.</i><br>
  *   If given, this function is called with the init data from the
  *   manifest/media and should return the (possibly transformed) init data to
@@ -664,6 +659,17 @@ shaka.extern.AdvancedDrmConfiguration;
  */
 shaka.extern.DrmConfiguration;
 
+/**
+ * @typedef {function(!Uint8Array, string, ?shaka.extern.DrmInfo):!Uint8Array}
+ *
+ * @description
+ * A callback function to handle custom content ID signaling for FairPlay
+ * content.
+ *
+ * @exportDoc
+ */
+shaka.extern.InitDataTransform;
+
 
 /**
  * @typedef {{