I kept wondering whether you’re supposed to call the parent init method before or after your code and I found a basic answer: init() { // Put values into your instance variables and constants super.init() // Other initialization code, such as calling methods, goes here }
Tag: swift
Generic Alert Method
Here is a generic alert method that you can place in a global functions/variables file that checks for an existing alert first. func showAlert(withTitle title: String, message: String, viewController: UIViewController) { if viewController.presentedViewController == nil { // Prevent multiple alerts at the same time let localizedTitle = NSLocalizedString(title, comment: “”) let localizedMessage = NSLocalizedString(message, comment:… Continue reading Generic Alert Method
Get Timestamps
This is just a random method I’m no longer using and wanted to get rid of but didn’t really want to throw it away in case I want to reference it someday. static func getTimestamps(forEntry entry: Entry?) -> [String: Int] { let calendar = NSCalendar.currentCalendar() let formatter = NSDateFormatter() formatter.dateFormat = “yyyy-MM-dd HH:mm:ss” var since… Continue reading Get Timestamps
Trim whitespace from a string in Swift
let whitespaceSet = NSCharacterSet.whitespaceCharacterSet() let trimmedString = myTextField.text!.stringByTrimmingCharactersInSet(whitespaceSet) if trimmedString.characters.count == 0 { print(“myTextField is blank”) }
Notifications in iOS
Posting a Notification First, create a global key before the class definition of the class that is posting the notification Post the notification
Add Share Button to iOS 9 App
@IBAction func export(sender: UIBarButtonItem) { if let data = prepareCSVData() { let filename = getDocumentsDirectory().stringByAppendingPathComponent(“data.csv”) data.writeToFile(filename, atomically: true) let url = NSURL(fileURLWithPath: filename) let activityViewController = UIActivityViewController(activityItems: [url], applicationActivities: nil) if let popoverController = activityViewController.popoverPresentationController { popoverController.barButtonItem = sender } presentViewController(activityViewController, animated: true, completion: nil) } else { NSLog(“Unable to prepare data”) } } The… Continue reading Add Share Button to iOS 9 App
Send Mail with Attachment in iOS
if MFMailComposeViewController.canSendMail() { let data = prepareCSVData() let mailController = MFMailComposeViewController() mailController.mailComposeDelegate = self mailController.setSubject(“Data Export”) mailController.setMessageBody(“Attached is a CSV file containing your data.”, isHTML: false) // Add attachment if let data = data { mailController.addAttachmentData(data, mimeType: “text/comma-separated-values”, fileName: “headaches.csv”) presentViewController(mailController, animated: true, completion: nil) } else { NSLog(“No data”) } }
Prevent “Array index out of range” Error in Swift
If you don’t know if the array index you are calling exists, here is a nice way to just return nil instead of an error. I grabbed this from StackOverflow but unfortunately lost the link. I am putting it here because I use it once in a while and get tired of searching for it.… Continue reading Prevent “Array index out of range” Error in Swift
Scroll to the Bottom of a Collection View
private func scrollToBottom() { let lastSectionIndex = (collectionView?.numberOfSections())! – 1 let lastItemIndex = (collectionView?.numberOfItemsInSection(lastSectionIndex))! – 1 let indexPath = NSIndexPath(forItem: lastItemIndex, inSection: lastSectionIndex) collectionView!.scrollToItemAtIndexPath(indexPath, atScrollPosition: UICollectionViewScrollPosition.Bottom, animated: false) }
Add a UITableView to an Existing ViewController in Xcode
Quick and dirty checklist for adding a table view to an existing view controller: Embed existing view controller in a NavigationController Drag a UITableView object into the view controller in the storyboard Make the UITableView the same width and height as the view controller and set the constraints to all four sides with no margins… Continue reading Add a UITableView to an Existing ViewController in Xcode