LESSONS LEARNED. SWIFT. Dagna Bieda, 7th April 2016

Transcription

1 LESSONS LEARNED. SWIFT Dagna Bieda, 7th April 2016

2 SWIFT & XCODE Brief Intro

3 Language that essentially marries the readability of Python with the speed of

4 SWIFT mix of good practices from multiple languages, rooted in C, statically typed language, no nil as we know it, let n = nil // type of expression is ambiguous without more context let i : Int? = nil // the result is actually Optional<Int>.None all variables must be initialized before using them, memory management done by Automatic Reference Counting, object-oriented, functional, generic, protocol-oriented,

5 SWIFT very large community, massive amount of free tutorials ( recently open-sourced, possible to create server backend using Kitura-IBM or Perfect

6 SWIFT. WHERE TO LEARN FROM stackoverflow.com youtube.com: Stanford - Developing ios 8 Apps with Swift udacity.com: A. Intro to ios App Development with Swift B. ios Developer Nanodegree edx.com coursera.com

7 XCODE enforces type-safety, // var was never changed, consider changing to let integrated with control management systems - git and SVN, code coverage, profiling, memory usage, leaks, test recording, storyboards <3

8 HEALTH CARE app case study

9 APP REQUIREMENTS Facilitate communication between patient and their nurse, Share health data of the patient on a daily basis, Share videos and/or documents, Simple management of multiple patients, Be easy to use (non tech-savvy users)

10 DEMO APP + TEST

11 CODE EXAMPLES import GRDB enum UserType: String, DatabaseValueConvertible { case Nurse = "Nurse", Patient = "Patient" var databasevalue: DatabaseValue { get { return DatabaseValue(object: self.rawvalue)! static func fromdatabasevalue(databasevalue: DatabaseValue) -> UserType? { let value = databasevalue.value() as! String return UserType(rawValue: value) func toggled() -> UserType { switch self{ case.nurse : return.patient case.patient : return.nurse

12 CODE EXAMPLES protocol DashboardDrawable { func setupat(origin: CGPoint, xoffset: CGFloat, size: CGSize, addtoview masterview: UIScrollView) class MessageView: UIView, DashboardDrawable { func setupat(origin: CGPoint, xoffset: CGFloat, size: CGSize, addtoview masterview: UIScrollView){ var frame = CGRect(origin: origin, size: size) frame.origin.x += xoffset self.frame = frame self.backgroundcolor = UserSettings.messageViewColor self.addlabels() masterview.addsubview(self)

13 CODE EXAMPLES protocol DashboardDrawable { func setupat(origin: CGPoint, xoffset: CGFloat, size: CGSize, addtoview masterview: UIScrollView) class MessageView: UIView, DashboardDrawable { func setupat(origin: CGPoint, xoffset: CGFloat, size: CGSize, addtoview masterview: UIScrollView){ var frame = CGRect(origin: origin, size: size) frame.origin.x += xoffset self.frame = frame self.backgroundcolor = UserSettings.messageViewColor self.addlabels() masterview.addsubview(self) // Usage in DashboardDetailTableViewController private func preparepatientdataforcell(cell: PatientDataCell, patient: Patient, date: NSDate, viewsize: CGSize) { let width = computedashboardselementwidth(viewsize.width) let size = CGSize(width: width, height: viewsize.height) let matchpatientsidandselecteddate = { (cp: ContactPointProtocol) -> Bool in return cp.patientid == patient.serverid && cp.date ~= date for message in dbwrapper.messages.filter(matchpatientsidandselecteddate) { let view = MessageView(message: message) let offset = timeline.calculatedateoffset(message.date) view.setupat(cgpointzero, xoffset: offset, size: size, addtoview: cell.patientdashboard)

14 CODE EXAMPLES!? protocol DateDisplayButtonDelegate: class { func datedidchange(newdate: NSDate) class DateDisplayButton: UIButton { var date: NSDate! { //! deferred initialization didset{ if oldvalue!= date { let components = NSCalendar.currentCalendar().components([.Month,.Day,.Weekday], fromdate: date) let weekday = Weekday(rawValue: components.weekday)!.description let month = Month(rawValue: components.month)!.description let day = components.day let title = String("\(weekday), \(month) \(day)") self.settitle(title, forstate:.normal) if oldvalue!= nil { delegate?.datedidchange(date) var delegate: DateDisplayButtonDelegate?

15 CODE EXAMPLES protocol DateDisplayButtonDelegate: class { func datedidchange(newdate: NSDate) class DateDisplayButton: UIButton { var date: NSDate! { didset{ if oldvalue!= date { \\... if oldvalue!= nil { delegate?.datedidchange(date) var delegate: DateDisplayButtonDelegate? class DashboardDetailTableViewController: UIViewController, UITableViewDelegate, UIScrollViewDelegate, UIPopoverDelegate, DateDisplayButtonDelegate weak var datedisplaybutton: DateDisplayButton! { didset { datedisplaybutton.delegate = self // MARK: DateDisplayButtonDelegate func datedidchange(newdate: NSDate) { preparepatientsdata(newdate)

16 CODE EXAMPLES private extension UIColor { class var random: UIColor { switch arc4random()%5 { case 0: return UIColor.greenColor() case 1: return UIColor.blueColor() case 2: return UIColor.orangeColor() case 3: return UIColor.redColor() case 4: return UIColor.purpleColor() default: return UIColor.blackColor() // Tuples and _ placeholder class TimelineDashboardHeader: UIScrollView { var majortics = [NSDate : (String, (UILabel, UIBezierPath))]() var minortics = [NSDate : (String, UIBezierPath)]() func calculatedateoffset(date: NSDate) -> CGFloat{ let roundeddate = roundeddowntonearesthalfhour(date) var tic: UIBezierPath? = UIBezierPath() if let (_, (_, tic)) = majortics[roundeddate] { let roundedx = tic.currentpoint.x let timedistance = CGFloat(date.timeIntervalSinceNow - roundeddate.timeintervalsincenow) let xoffset = roundedx + (timedistance/majorticstimespan * intervalsize) return xoffset else { return 0.0

17 NOT SO FUN PART casting Int or Double to CGFloat func frameformenubutton(indexpath: NSIndexPath) -> CGRect { let row = indexpath.row / numberofcolumns let column = indexpath.row % numberofcolumns let originx: CGFloat = floor((itemsize.width + horizontalspace) * CGFloat(column)) let originy: CGFloat = floor((itemsize.height + verticalspace) * CGFloat(row)) return CGRectMake(originX, originy, itemsize.width, itemsize.height) mysterious UIScrollView in to denote end of a closure s type signature protocol with a settable variable has to be restricted to classes (it not a struct with a mutating setter which should be allowed)

18 #ifdef greatpresentation #include standing-ovation.hpp #endif THANK YOU!