KotlinKronicles-extensions-02.kt

import android.database.sqlite.SQLiteDatabase

// Add an extension function to perform SQLite operations
// This is a higher order function as it takes a function as parameter (operation)
// @param operation: a function that takes no parameter and returns nothing
fun SQLiteDatabase.performDBTransaction(operation: () -> Unit) {
    beginTransaction()
    operation() // this is the passed function
    endTransaction()
}

val db: SQLiteDatabase = DBHandler.getInstance(...)

// invoke the extension function like a pro
db.performDBTransaction { 
    // Any DB transaction here
    // without worrying whether you called endTransaction()
}
// invoke the function like DSL