bSqlVCardCallback

If this callback is passed to BookSqlite, then vcards are not stored in the SQLite and instead this callback is invoked to fetch the vcard.

This callback will be called to fetch results for fully indexed and optimized queries, and it will also be called while performing fallback queries against ContactFields which are not configured in the SourceBackendSummarySetup or default summary fields.

<note><para>This user callback is called inside a lock, you must not call the BookSqlite API from this callback.</para></note>

Parameters:

uid	A contact UID
extra	The extra data associated to the contact
user_data	User data previously passed to BookSqlite

Returns:

The appropriate vcard indicated by uid