Hi im new in swift and im trying to build a store application, i already build it but i have a problem with only one thing which is , i want to pass the data ( label, image, price label ) to another viewController without using segue. I tried all the method ( delegate, notificationCenter, closure ) but i didn't solve it.
this is a picture for new project i create it to explain what i want to do exactly .
i hope i get the solution because i search alot for it maybe for months but i didn't solve my problem :(
this is my code
passingViewController
import UIKit
extension passingDataViewController : textDelegate {
func sendText(withText: String) {
Label.text = withText
}
}
class receivingDataViewController: UIViewController {
#IBOutlet var label2: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
}
receivingDataViewController
import UIKit
extension passingDataViewController : textDelegate {
func sendText(withText: String) {
Label.text = withText
}
}
class receivingDataViewController: UIViewController {
#IBOutlet var label2: UILabel!
override func viewDidLoad() {
super.viewDidLoad()
}
}
You didn't explain how you're creating the new controllers, but here's a simple example that just uses a tab controller. This makes use of a shared singleton to pass around the delegate, but if you're creating each controller programatically, you could update the delegate when you create each new instance.
For this example, I have created a singleton that contains the delegate
import Foundation
class SharedSingleton : NSObject
{
var updateDelegate : UpdateDelegate?
static let sharedInstance = SharedSingleton()
}
And then we define the protocol you're using.
In the passing view, you can define it like this
protocol UpdateDelegate
{
func updateDisplay(text : String)
}
and you use it (in the passing view like this
var sharedInstance = SharedSingleton.sharedInstance
#IBAction func cmdGo(_ sender: Any) {
sharedInstance.updateDelegate!.updateDisplay(text: txtInput.text!)
}
You define the receiving view to use the update protocol
class ReceivingViewController: UIViewController, UpdateDelegate {
and set up the delegate
var sharedInstance = SharedSingleton.sharedInstance
override func viewDidLoad() {
super.viewDidLoad()
// setup the delegate through the shared instance
sharedInstance.updateDelegate = self
}
and then implement the update method
func updateDisplay(text: String) {
lblDisplay.text = text
}
That's it. You may need to update your implementation to change how you share the delegate pointer, but that's the process.
I'm trying to retrieve data from Parse using findObjectsInbackground and store it in an array. I've already created outside the scoop of viewDidLoad().
I managed retrieving and printing the data, but they are not stored in the array and it keeps being empty!
I used self.articalsTableView.reloadData() but unfortunately the array myArray is still empty.
Any help please, this has been confusing me for two days!
import UIKit
import Parse
class FirstViewController: UIViewController, UITableViewDelegate, UITableViewDataSource {
#IBOutlet weak var articalsTableView: UITableView!
var myArray = [PFObject]()
override func viewDidLoad() {
super.viewDidLoad()
let query = PFQuery(className: "Gateshead")
query.findObjectsInBackground {(objects, error) -> Void in
if error != nil {
print(error)
} else {
if let articals = objects {
for artical in articals {
// print (articles) THIS IS WOKING WELL
self.myArray.append(artical)
self.articalsTableView.reloadData()
}
}
}
}
}
}
findObjectsInback is using a background thread and you should dispatch to mainThread whenever if you want to access UIKit stuff in this case updating self.articalsTableView.
Also self.articalsTableView.reloadData() should be called at the end (not in the loop). This to prevent a race condition on self.myArray being accessed by the main-thread (to update self.articalsTableView ) and by the background-thread (to append artical)
for artical in articals {
// print (articles) THIS IS WOKING WELL
self.myArray.append(artical)
}
DispatchQueue.main.async {
self.articalsTableView.reloadData()
}
I have two arrays: FirstTableArray (include name of brands) and SecondTableArray (include models).
I want to add search through which the model of phone can be found by part of name.
import UIKit
import MessageUI
class FirstTableViewController: UITableViewController {
var FirstTableArray = [String]()
var SecondTableArray = [SecondTable]()
override func viewDidLoad() {
super.viewDidLoad()
self.navigationController?.navigationBar.isTranslucent = false
self.navigationController?.navigationBar.barStyle = .black
self.navigationController?.navigationBar.tintColor = UIColor.white
// First Table Array
FirstTableArray = ["Apple", "Samsung"]
// Second Table Array
SecondTableArray = [
SecondTable(SecondTitle: ["iPhone 5s", "iPhone 6", "iPhone 6s"]),
SecondTable(SecondTitle: ["Galaxy S4", "Galaxy S5", "Galaxy S6"]),
]
}
override func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
return FirstTableArray.count
}
override func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let Cell = self.tableView.dequeueReusableCell(withIdentifier: "Cell", for: indexPath) as UITableViewCell
Cell.textLabel?.text = FirstTableArray[(indexPath as NSIndexPath).row]
return Cell
}
override func prepare(for segue: UIStoryboardSegue, sender: Any?) {
let indexPath : IndexPath = self.tableView.indexPathForSelectedRow!
let DestViewController = segue.destination as! SecondTableViewController
let SecondTableArrayTwo = SecondTableArray[(indexPath as NSIndexPath).row]
DestViewController.SecondTableArray = SecondTableArrayTwo.SecondTitle
}
}
Can you help me with this?
I'm working through the same thing today and found this tutorial very easy to follow: https://github.com/codepath/ios_guides/wiki/Search-Bar-Guide
It will take you through the steps of adding the search bar in Interface Builder, setting up the delegate, and including a method to filter the results.
Providing a way for users to search through a collection of items is a fairly common task in iOS projects. A standard interface for implementing search behaviors is the search bar.
There are a few common ways to work with Search Bars:
Directly using a UISearchBar. This is the most bare bones way to use
UISearchBars. This can be extremely flexible if you want to design
and program your own search interface, however does not provide as
many built-in features as the other methods.
Using a UISearchDisplayController to help manage a search interface.
The UISearchDisplayController allows you to present a standard search
interface with built-in animations. This method forces you to display
search results in a table view. - DEPRECATED
Using a UISearchController to help manage a search interface. The
UISearchController is a newer controller (available only in iOS 8+)
that helps you present a search interface using any kind of view to
display the search results.
This guide covers the very basics of working with each of these classes. None of these classes actually implements the "searching" behavior of finding items that match a given query string, since determining which objects match will vary with the domain specific use case (e.g. when searching for "people" you might want to match on just their names, whereas you may want a full-text pre-indexed search when searching through e-mails). You'll have to implement any search/filtering behavior yourself.
Working with UISearchBars directly
At its core, a search bar is nothing more than a glorified text field packaged with a scope control and some animations and a couple of buttons. Each search bar has a delegate that gives you an opportunity to respond to user actions. The most important delegate methods are:
textDidChange - most of the time you'll respond to this event by
updating the displayed set of search results as the user is typing
out a query
searchBarSearchButtonClicked - in some cases if the search operation
is slow (e.g. requires making a slow API call) you'll want to wait
until the user taps the search button before updating the search
results.
Example searching a table
We start out with a single view application with a basic UITableView. You can add a UISearchBar as you would with any other control by dragging one to your view controller in interface builder or by programmatically adding it.
The delegate property of search bar must be set to an object that implements UISearchBarDelegate. Typically you make your view controller implement UISearchBarDelegate and set searchBar.delegate = self in viewDidLoad method.
The code to implement the search behavior is as follows. We maintain an additional array filteredData to represent rows of data that match our search text. When the search text changes we update filteredData and reload our table.
class ViewController: UIViewController, UITableViewDataSource, UISearchBarDelegate {
#IBOutlet weak var tableView: UITableView!
#IBOutlet weak var searchBar: UISearchBar!
let data = ["New York, NY", "Los Angeles, CA", "Chicago, IL", "Houston, TX",
"Philadelphia, PA", "Phoenix, AZ", "San Diego, CA", "San Antonio, TX",
"Dallas, TX", "Detroit, MI", "San Jose, CA", "Indianapolis, IN",
"Jacksonville, FL", "San Francisco, CA", "Columbus, OH", "Austin, TX",
"Memphis, TN", "Baltimore, MD", "Charlotte, ND", "Fort Worth, TX"]
var filteredData: [String]!
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
searchBar.delegate = self
filteredData = data
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCell(withIdentifier: "TableCell", for: indexPath) as UITableViewCell
cell.textLabel?.text = filteredData[indexPath.row]
return cell
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return filteredData.count
}
// This method updates filteredData based on the text in the Search Box
func searchBar(_ searchBar: UISearchBar, textDidChange searchText: String) {
// When there is no text, filteredData is the same as the original data
// When user has entered text into the search box
// Use the filter method to iterate over all items in the data array
// For each item, return true if the item should be included and false if the
// item should NOT be included
filteredData = searchText.isEmpty ? data : data.filter({(dataString: String) -> Bool in
// If dataItem matches the searchText, return true to include it
return dataString.range(of: searchText, options: .caseInsensitive) != nil
})
tableView.reloadData()
}
}
Here's what this looks like when running. Notice that the search results are displayed in the same table, and there is no presentation of a separate search interface.
Example searching a collection view
Since the UISearchBar is quite simple, it can be combined with any abitrary view to build your own search interface. Here's what it might look like paired with a collection view.
The code for this is essentially the same as in the case with table views.
Cancelling out of Search and hiding keyboard
Once user taps on search bar, the keyboard will appear, and you will notice that it won't go away when you tap on X. You can show Cancel button when user taps on search bar, and when user taps on Cancel, hide the keyboard.
There is a nifty searchBarTextDidBeginEditing method for UISearchBarDelegate that gets called when user starts editing search text. You can show Cancel button in that method:
func searchBarTextDidBeginEditing(_ searchBar: UISearchBar) {
self.searchBar.showsCancelButton = true
}
When user taps on cancel button, delegate's searchBarCancelButtonClicked method gets called. At this point, you can hide the Cancel button, clear existing text in search bar and hide the keyboard like this:
func searchBarCancelButtonClicked(_ searchBar: UISearchBar) {
searchBar.showsCancelButton = false
searchBar.text = ""
searchBar.resignFirstResponder()
}
Using UISearchControllers (iOS 8+)
A newer way to manage the presentation of a search interface (only available in iOS 8 and above) is via the UISearchController. This controller handles some of the logic and animation of presenting a separate search interface for you while still allowing you to specify how your search results are displayed.
Example searching a table
There is currently no built-in object in the Interface Builder Object Library for a UISearchController. The easiest way to create one is to do it programatically. This also creates a UISearchBar and sets the search controller's searchBar property to it. You can add this search bar to your view hierarchy programatically.
In order to update your search results you'll have to implement the UISearchResultsUpdating protocol and set the search controller's searchResultsUpdater property.
You don't need to implement the UISearchControllerDelegate unless you need to hook into the events around the presentation of the search interface.
Putting it all together the code looks like this. Notice that we have to read the search text from the search bar in updateSearchResultsForSearchController. One other thing to note is that we set this view controller's definesPresentationContext property to true. This means that the search controller should use this view controller's frame (as oppposed to the root view controller) when presenting the search interface. In this case it means that the search interface will expand above the carrier bar.
class ViewController: UIViewController, UITableViewDataSource, UISearchResultsUpdating {
#IBOutlet weak var tableView: UITableView!
let data = ["New York, NY", "Los Angeles, CA", "Chicago, IL", "Houston, TX",
"Philadelphia, PA", "Phoenix, AZ", "San Diego, CA", "San Antonio, TX",
"Dallas, TX", "Detroit, MI", "San Jose, CA", "Indianapolis, IN",
"Jacksonville, FL", "San Francisco, CA", "Columbus, OH", "Austin, TX",
"Memphis, TN", "Baltimore, MD", "Charlotte, ND", "Fort Worth, TX"]
var filteredData: [String]!
var searchController: UISearchController!
override func viewDidLoad() {
super.viewDidLoad()
tableView.dataSource = self
filteredData = data
// Initializing with searchResultsController set to nil means that
// searchController will use this view controller to display the search results
searchController = UISearchController(searchResultsController: nil)
searchController.searchResultsUpdater = self
// If we are using this same view controller to present the results
// dimming it out wouldn't make sense. Should probably only set
// this to yes if using another controller to display the search results.
searchController.dimsBackgroundDuringPresentation = false
searchController.searchBar.sizeToFit()
tableView.tableHeaderView = searchController.searchBar
// Sets this view controller as presenting view controller for the search interface
definesPresentationContext = true
}
func tableView(tableView: UITableView, cellForRowAtIndexPath indexPath: NSIndexPath) -> UITableViewCell {
let cell = tableView.dequeueReusableCellWithIdentifier("TableCell") as UITableViewCell
cell.textLabel?.text = filteredData[indexPath.row]
return cell
}
func tableView(tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return filteredData.count
}
func updateSearchResultsForSearchController(searchController: UISearchController) {
if let searchText = searchController.searchBar.text {
filteredData = searchText.isEmpty ? data : data.filter({(dataString: String) -> Bool in
return dataString.rangeOfString(searchText, options: .CaseInsensitiveSearch) != nil
})
tableView.reloadData()
}
}
}
Here's what this looks like when running. Notice that unlike in the search display controller example, we are using the same table view to display the search results instead of overlaying of a separate table view. However, unlike when working with just the search bar, we still have the built in animation when transitioning to the search interface.
Also, you get the logic to show Cancel button and hide keyboard when user taps on cancel button for free when you use this.
Example searching a collection view
We can just as easily use the search controller to search a collection view in place. We still have the presentation of a search interface, but unlike when working with the search display controller we are not restricted to using a table view to display the search results.
The code for this is almost the same as when searching the the table view above. The only notable difference is that we had to introduce a placeholder view in interface builder for the search bar since there are still some quirks with placing a search controller's search bar inside a collection view's supplementary view.
class ViewController: UIViewController, UICollectionViewDataSource, UISearchResultsUpdating {
#IBOutlet weak var collectionView: UICollectionView!
#IBOutlet weak var searchBarPlaceholder: UIView!
...
override func viewDidLoad() {
...
searchController.searchBar.sizeToFit()
searchBarPlaceholder.addSubview(searchController.searchBar)
automaticallyAdjustsScrollViewInsets = false
definesPresentationContext = true
}
...
}
Search Bar in Navigation View
A common requirement is to place the search bar inside the navigation bar.
This can be configured programatically in your view controller's viewDidLoad as follows.
When working directly with a search bar:
// create the search bar programatically since you won't be
// able to drag one onto the navigation bar
searchBar = UISearchBar()
searchBar.sizeToFit()
// the UIViewController comes with a navigationItem property
// this will automatically be initialized for you if when the
// view controller is added to a navigation controller's stack
// you just need to set the titleView to be the search bar
navigationItem.titleView = searchBar
Using a search display controller:
searchDisplayController?.displaysSearchBarInNavigationBar = true
Using a search controller:
searchController.searchBar.sizeToFit()
navigationItem.titleView = searchController.searchBar
// By default the navigation bar hides when presenting the
// search interface. Obviously we don't want this to happen if
// our search bar is inside the navigation bar.
searchController.hidesNavigationBarDuringPresentation = false
I would suggest implemeting a UISearchBar and adding your class as a delegate to the UISearchBar and then in the delegates methods you can take the searchbar text and perform the search on the datasouce and then reload the tableview data accordingly
Edit: You can use this tutorial for how to implement UISearchBar on a UITableView
https://www.raywenderlich.com/472-uisearchcontroller-tutorial-getting-started
So I am probably doing this all wrong but I want to make a shopping list app and I have two view controllers, one with the list and one with a textbook and button to add to the list but I can't figure out how to get the array to the other class. I have this code so far and the error I get is
Instance member 'list' cannot be used in type 'mainViewController'
And this is my code
import UIKit
class mainViewController: UIViewController {
var list:[String] = [""]
#IBOutlet weak var item: UITextField!
override func viewDidLoad() {
super.viewDidLoad()
self.hideKeyboardWhenTappedAround()
// Do any additional setup after loading the view.
}
func hideKeyboardWhenTappedAround() {
let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(mainViewController.dismissKeyboard))
view.addGestureRecognizer(tap)
}
func dismissKeyboard() {
view.endEditing(true)
}
#IBAction func AddToList(sender: UIButton) {
list.append(item.text!)
}
static func getList(inout Array: [String]) -> [String] {
return list
}
}
Any help much appreciated, please keep it positive though and keep in mind I am very new to this forum and swift. Thanks!
The error message is very clear that you are trying to access an instance field in type context (without instance).
To fix it, just remove static in getList function.
PS: Please follow Swift naming conventions to capitalize your class name
I am trying to create a global array (of items in a cart) in Swift so that I can access it from different pages.
Can you please point me in the right direction? declaring an array under the import statement in AppDelegate gives me the "unresolved Identifier" issue.
What should I use? How can I accomplish that? Thank you!
In swift you can encapsulate variables in a struct and you can access them anywhere.
struct GlobalVariables {
static var globalString = "MyString"
}
To call it
// Get value
let str = GlobalVariables.globalString
// Set value
GlobalVariables.globalString = "New value"
Checkout the reference for more information.
first controller: declare variable
import UIKit
class ViewController: UIViewController {
var test2 = 5
override func viewDidLoad() {
super.viewDidLoad()
}
}
second controller call variable
class ViewController1: UIViewController {
var myCustomViewController: ViewController = ViewController()
override func viewDidLoad() {
super.viewDidLoad()
print(myCustomViewController.test2)
} }