String Array as Data Source for UIPickerView

Question

I am having trouble populating a UIPickerView with an array of strings with each row being one selection. I am creating a UIPicker outlet in my ViewController class and making changes to my UIPicker as data is generated from the main.async call.

// Creating our UIView Controller WeldFloorController
// WeldFloorController provides functionality to the WeldFloor screen

class WeldFloorController: UIViewController{

    // Defining the regex String to be used
    let regexString = String( """
((?:<div id=\\d{1,3}>)(UID:\\d{1,3})(currentPartNumber:(.{0,20}))(workcenter:(.{0,20}))(cycleTime:(.{0,20}))(curPartCycleTime:(.{0,20}))(partsMade:(.{0,20}))(CycleTimeActual:(.{0,20}))(target:(.{0,20}))(actual:(.{0,20}))(downtime:(.{0,20}))(statusReason:(.{0,30}))(lineStatus:(.{0,50}))(efficiency:(.{0,20}))(plusminus:(.{0,20}))(curProdTime:(.{0,30}))(<\\/div>))
""");

    // Defining Main Thread for Data updates
    let main = DispatchQueue.main;

    // Intializing all usable objects on screen
    @IBOutlet weak var weldFloorProductionPicker: UIPickerView!;
    @IBOutlet weak var weldFloorDataDisplay: UICollectionView!;

    // Configuring objects on screen happens within viewDidLoad()
    // P*S Since the exectution is happening asynchronous so
    // all updates must be made from within WorkcenterStatus.sharedInstance.run { }
    override func viewDidLoad() {

        // INITIAL CONFIGURATION OF OBJECTS (SUCH AS defaultText etc..) DONE HERE


        // END CONFIG

        // Starting WebService
        WorkcenterStatus.sharedInstance.run { result in
            switch result {

            // If Successful then execute main.async
            // In other words execute everything in .success
            // when webService == Successful
            // [execute main.async] { code here }

            case .success(let htmlBody): self.main.async {
                // First operation -- Return all matches into an array of Strings
                let returnHtml = matches(for: self.regexString, in: htmlBody);

                // Second operation -- For each match return an integer
                let dataPoints = returnHtml.count;

                // Third operation -- Populate our UICollections with our data                   
                // Sub Operation #1 -- Creating the dataSource
                // Edit** I kept this here for one thing ^^ DataSources should be called
                // from a seperate class file or library -- Using dataSources built within
                // the viewController are not reusable unless the dataSource is delegated
                // to another ViewController which at the point it would be just better
                // to create another lib file
                // and call that from there

                // Sub Operation #1 Actual -- Setting a dataSource object


                self.weldFloorProductionPicker.dataSource = returnHtml[];

                };

            // If failed then print error
            case .failure(let error): print(error)
            };
        };
        // Additional Setup
        super.viewDidLoad()
        // Do any additional setup after loading the view.
    };
};

self.weldFloorProductionPicker.dataSource = returnHtml[]; Is this not a valid way to identify that I want to set the dataSource as the array and all its values? The Array is 1 dimensional and the error I am getting is Cannot subscript a value of type '[String]' with an index of type '()' Any help would be greatly appreciated

Thanks,

Just remove the []. And this is Swift: No trailing semicolons! — vadian
– vadian, Commented Jul 18, 2019 at 15:16
Hey @vadian thanks for the reply! I know I have seen you on another question of mine - habits die hard what I can say! Anyhow I did as you advised and I am now returning a Cannot assign value of type '[String]' to type 'UIPickerViewDataSource?' Any ideas?? — HRD1997BFBE
– HRD1997BFBE, Commented Jul 18, 2019 at 16:00
Basically your approach is wrong. Follow Sh_Khan's suggestion. — vadian
– vadian, Commented Jul 18, 2019 at 16:02

Shehata Gamal · Accepted Answer · 2019-07-18 15:18:38Z

1

You can try

class ViewController: UIViewController , UIPickerViewDelegate,UIPickerViewDataSource {

   var arr = [String]()

  override func viewDidLoad() {   
    super.viewDidLoad()

    self.weldFloorProductionPicker.delegate = self
    self.weldFloorProductionPicker.dataSource = self 

    WorkcenterStatus.sharedInstance.run { result in

        switch result { 
          case .success(let htmlBody):  
            let returnHtml = matches(for: self.regexString, in: htmlBody)
               self.arr = returnHtml 
                DispatchQueue.main.async {
                  self.weldFloorProductionPicker.reloadAllComponents()
                }
            }

        // If failed then print error
        case .failure(let error): 
              print(error)
        }
    }
  }

    func numberOfComponents(in pickerView: UIPickerView) -> Int {
        return 1
    }

    func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
        return arr.count
    }

    func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
        return arr[row]
    }

}

answered Jul 18, 2019 at 15:18

Shehata Gamal

101k8 gold badges75 silver badges95 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

HRD1997BFBE Over a year ago

Could you explain a bit what you are doing?? You switched the class structure around - are you extending the ViewController Class when you do class ViewController: UIViewController , UIPickerViewDelegate,UIPickerViewDataSource {

Collectives™ on Stack Overflow

String Array as Data Source for UIPickerView

1 Answer 1

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related