Save context and propagate changes to any parent contexts

NSManagedObjectContext_saveToPersistentStore.swift

import CoreData
 
extension NSManagedObjectContext {
    /// Commit unsaved changes and propagate them to ancestor contexts, if any.
    ///
    /// :param: error A pointer to an NSError object returned on failure
    /// :returns: true if the operation succeeds, false otherwise
    @objc(kdj_saveToPersistentStore:)
    public func saveToPersistentStore(error: NSErrorPointer) -> Bool {
        if !self.save(error) {
            return false
        }
 
        // If this is a child context, recursively invoke this method
        // on its parent context
        if let parentContext = self.parentContext {
            var parentResult: Bool = false
            parentContext.performBlockAndWait {
                parentResult = parentContext.saveToPersistentStore(error)
            }
            return parentResult
        }
        else {
            return true
        }
    }
}