RealmSwift - transaction completion

Question

How do I know when a particular transaction has completed?

I want to run a particular block of code after a transaction is complete. How can I do this?

I am performing writes in the following war -

do {

  try realm.write({
    realm.add(<some object>)
  })
}
catch {}

Answer 1

Best approach would be to write the method as an extension for Realm object.

For Swift 3+

extension Realm {

    /// Performs actions contained within the given block 
    /// inside a write transaction with completion block.
    ///
    /// - parameter block: write transaction block
    /// - parameter completion: completion executed after transaction block
    func write(transaction block: (Void) -> Void, completion: (Void) -> Void) throws {
        try write(block)
        completion()
    }
}

Swift 2.0

extension Realm {

    /** Performs actions contained within the given block inside a write transaction with
    completion block.

     - parameter block: write transaction block
     - completion: completion executed after transaction block
    */
    func write(@noescape transactionBlock block: Void -> (), completion: Void -> ()) throws {
        do {
            try write(block)
            completion()
        } catch {
            throw error
        }
    }
}

Now you can use the extension just like a regular write(_:) method.

let realm = try! Realm()
let object = SomeObject()

try! realm.write(
        transactionBlock: {
            realm.add(object)
        },
        completion: {
            print("Write transaction finished")
    })