We continue our series on “modern persistence” with an important topic: “callbacks.” Callbacks are little hooks into the lifecycle of your data model so that you can be notified or take action when something changes. We will first explore the “Active Record” pattern of callbacks, popularized by Ruby on Rails, and then see how we can improve upon them.

How does our SQL-based solution for persistence compare with modern SwiftData? We put things to the test by rebuilding our complex @FetchAll query using @Model and the @Query macro!

We finish a sneak peek of our upcoming Structured Queries library by showing how queries built with the library can be reused and composed together, and how we can replace all of the raw queries in our application with simpler, safer query builders.

We show how to add iCloud synchronization to the persistence layer of an existing SQLite application by using SQLiteData. While SQLiteData’s CloudKit tools can be configured with a single line of code, one must still prepare their database schema to be compatible and durable when it comes to synchronizing across multiple devices and versions.

We round out modern search by diving into FTS5’s query syntax language. We’ll learn how it works, how to escape terms sent directly by the user, and we’ll introduce SwiftUI search tokens that can refine a query by term proximity and tags.

SQLite’s full-text search capabilities come with many bells and whistles, including support for highlighting search term matches in your UI, as well as generating snippets for where matches appear in a larger corpus. We will take these APIs for a spin and enhance our Reminders search UI.