BusNumberListViewController.swift

//
//  BusNumberListViewController.swift
//  ETA
//
//  Created by Pedro Remedios on 16/01/15.
//  Copyright (c) 2015 Pedro Remedios. All rights reserved.
//
import UIKit
import CoreData

class BusNumberListViewController: UIViewController, UITableViewDelegate, UITableViewDataSource, ImportOperationDelegate {

    @IBOutlet weak var tableView: UITableView!
    
    var progressHUD: M13ProgressHUD? = nil
    
    override func viewDidLoad() {
        super.viewDidLoad()
    }
    
    override func viewDidAppear(animated: Bool) {
        super.viewDidAppear(animated)
        self.progressHUD = M13ProgressHUD(andShowWithProgressView: M13ProgressViewRing(), progress: 0.5, indeterminate: false, status: "", mask: M13ProgressHUDMaskTypeSolidColor , inView: self.tableView)
        self.progressHUD!.progressViewSize = CGSize(width: 100, height: 100)
        var progressViewRing = self.progressHUD!.progressView as M13ProgressViewRing
        progressViewRing.progressRingWidth = 5.0
        self.progressHUD!.progressView = progressViewRing
        var importOperation = ImportOperation(database: ETADatabase(), delegate: self)
        // Here is where I update the progress HUD
        importOperation.progressCallback = { (progress) -> () in
            NSOperationQueue.mainQueue().addOperationWithBlock({ () -> Void in
                self.progressHUD!.setProgress(progress, animated: true)
                self.navigationController!.setProgress(progress, animated: true)
                self.navigationController!.showProgress()
                if progress >= 1 {
                    self.progressHUD!.performAction(M13ProgressViewActionSuccess, animated: true)
                    self.progressHUD!.hide(true)
                    self.navigationController!.finishProgress()
                    
                }
            })
        }
        importOperation.start()
    }

    func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return 4
    }
    
    func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
        var cell = self.tableView.dequeueReusableCellWithIdentifier("Cell") as UITableViewCell
        return cell
    }
    
    func didGetNumberOfLines(numberOfLines: Int) {
        self.progressHUD!.status = "Importing \(numberOfLines) records"
        self.navigationController!.setProgressTitle("Importing \(numberOfLines) records")
    }
}

ImportOperation.swift

//
//  ImportOperation.swift
//  ETA
//
//  Created by Pedro Remedios on 22/02/15.
//  Copyright (c) 2015 Pedro Remedios. All rights reserved.
//

import UIKit
import CoreData

typealias ProgressCallback = (_:CGFloat) -> Void

class ImportOperation: NSOperation {
    
    let etaDatabase:ETADatabase!
    let delegate: ImportOperationDelegate? = nil
    
    var progressCallback:ProgressCallback? = nil
    
    init(database:ETADatabase, delegate:ImportOperationDelegate) {
        self.etaDatabase = database
        self.delegate = delegate
    }
    
    override func main() {
        importCSV()
    }
    
    func importCSV() {
        let temposDeEsperaPath = NSBundle.mainBundle().pathForResource("tempos_de_espera", ofType: "csv")
        let fileContents = NSString(contentsOfFile: temposDeEsperaPath!, encoding: NSUTF8StringEncoding , error: nil)
        let fileLines = fileContents!.componentsSeparatedByCharactersInSet(NSCharacterSet.newlineCharacterSet()) as [String]
        
        self.delegate?.didGetNumberOfLines(fileLines.count)
        
        var privateContext = self.etaDatabase.createPrivateContext()
        var error: NSError?
        for (index, line) in enumerate(fileLines) {
            let lineContents = line.componentsSeparatedByString(",") as [String]
            privateContext.performBlock({ () -> Void in
                var bus = Bus(entity:NSEntityDescription.entityForName("Bus", inManagedObjectContext: privateContext)!, insertIntoManagedObjectContext:privateContext)
                bus.carreira = lineContents[0]
                bus.sentido = lineContents[1]
                bus.numero = lineContents[2]
                bus.paragem = lineContents[3]
                bus.localizacao = lineContents[4]
                bus.destino = lineContents[5]
                bus.codigo = lineContents[6]
                //println("\(CGFloat(index)) \(CGFloat(fileLines.count))")
                // Here is where I set the progress to pass back to the callback
                let importProgress:CGFloat = CGFloat(index) / CGFloat(fileLines.count)
                println(importProgress)
                //println("index: \(index), count: \(fileLines.count)")
                if let callback = self.progressCallback {
                    callback(importProgress)
                }
            })
        }
        privateContext.save(&error)
        if let callback = self.progressCallback {
            callback(1)
        }
    }
}

protocol ImportOperationDelegate {
    func didGetNumberOfLines(numbeOfLines: Int)
}