Adding a Custom SQLite Library for PDF Search on iOS

PSPDFKit for iOS doesn’t include a custom version of SQLite, as iOS comes with SQLite already bundled. Depending on the version of iOS, this version is different and will also have different capabilities enabled:

If you see SQLite log warnings, read up on our troubleshooting tips.

Check the SQLite website to see which version is the most current. Sometimes your app requires a specific SQLite version. Examples of such cases include:

• You need to have the same SQLite version on every iOS version you support.

• You want to use some new SQLite features that aren’t yet available in SQLite shipped with iOS.

• You want to encrypt your SQLite database (see SQLite Database Encryption).

• You want to use FTS5 with PDFLibrary.

In such cases, you usually link your app with a custom build of SQLite.

Detect Which Version Is Currently Active

Call the following in code to see which version of SQLite you currently use:

// e.g. "3016000" for macOS 10.12.4
int sqliteVersion = sqlite3_libversion_number();

PSPDFKit and a Custom SQLite Library

PSPDFKit is dynamically linked with the SQLite library provided by the iOS SDK. However, if you link your app with a custom SQLite library, PSPDFKit will automatically use it. You might want to remove the -lsqlite3 string from PSPDFKit.xcconfig inside the framework to remove the system linking.

Make sure your custom SQLite library is built with the following flags:

• SQLITE_THREADSAFE=1 or SQLITE_THREADSAFE=2

And if you’re using PDFLibrary, ensure you have the following flag to use FTS5:

• SQLITE_ENABLE_FTS5

And the following flags to use FTS4:

• SQLITE_ENABLE_FTS3

• SQLITE_ENABLE_FTS3_PARENTHESIS

PSPDFKit expects these options and fails early if any of them are missing.