Along with nixing iTunes, Apple is removing support for the method many DJ app developers had been using to access XML playlist files that let users access their iTunes music libraries.
DJs use XML file support to sort tracks into playlists and use iTunes’ “Share iTunes Library XML with other applications” to transfer data between apps.
Apple provided a statement to The Verge on the end of XML file support with the sunsetting of the iTunes app:
The Music app on the Mac is brand new with a modern library format. The frameworks for access to the library are still supported for developers to directly access music on your Mac, however, XML file support is no longer available on macOS Catalina. Apple is working closely with app developers to make sure their software is updated and compatible with Catalina. However, customers that are using an app that is not supported should contact the developer directly, or if it’s a mission-critical app in their workflow, we recommend they continue using that app on macOS Mojave until the developer updates. iTunes on Windows has not changed, so apps should function as normal.
In the statement, Apple says it is “working closely” with app developers to make sure software is updated and compatible with Catalina, and customers using an XML app that is not supported should continue to use macOS Mojave until developer updates are implemented.
We spoke with Michael Simmons of Algoriddim, the developer behind the djay Pro apps, and he pointed us to a previous report outlining how Apple launched an official SDK for delivering programmatic access to users’ music libraries with the launch of iTunes 11 a number of years ago, and apps like djay Pro that previously transitioned to the SDK will have no problems continuing to integrate with Music libraries in macOS Catalina.
App developers who have continued to rely on the earlier undocumented XML integration and have not updated in time will find that their users will be unable to access their Music libraries after upgrading to Catalina. Companies like Serato and Native Instruments have warned their users not to upgrade to macOS Catalina yet, although Native Instruments has a public beta of its Traktor Pro app available that will support Catalina.