PickerViewKit

Easily setup your UIPickerView’s using a model-based approach

With PickerViewKit you can quickly setup your picker views and provide data. Don’t worry about creating a data source and delegate anymore. Use models for configuration and data supply.

How to use

A UIPickerView consists of components and rows. Components are the columns of the picker view. Each column can have multiple rows. The PickerViewKit represents a column with the value type PickerViewColumn and a row with PickerViewRow. Rows can have a model which comes into play on row selection. Models can be implemented using PickerViewRowModelProtocol. The SimpleRowModel is used as a default row model.

1. If your rows should represent a specific model implement a custom row model using PickerViewRowModelProtocol.

2. Create your rows using PickerViewRow.

3. Attach your rows to a PickerViewColumn. Set a row height for the column if you want.

4. Use PickerViewSetup to define all parameters for the picker view configuration. To be notified about row selections pass a callback/delegate implementing PickerViewDelegateCallbackProtocol.

5. Instantiate a PickerViewManager with your PickerViewSetup.

Now you are ready to go. You can update the columns or the rows in a column using your manager instance.

final class ViewController: UIViewController {
    @IBOutlet private weak var pickerView: UIPickerView!

    private var manager: PickerViewManager?

    override func viewDidLoad() {
        super.viewDidLoad()

        // 1.
        struct CustomPickerViewRowModel: PickerViewRowModelProtocol {
            var name: String
            var description: String
            var history: String
        }

        // 2.
        var pickerViewRow: PickerViewRow {
            let model = CustomPickerViewRowModel(name: "Germany", description: "The Republic of Germany", history: "Germany has a long history ...")
            var row = PickerViewRow(type: .plain(title: model.name))
            row.model = model
            return row
        }

        // 3.
        let pickerViewColumn = PickerViewColumn(rows: [pickerViewRow], rowHeight: 56.0)

        // 4.
        let pickerViewSetup = PickerViewSetup(pickerView: pickerView, columns: [pickerViewColumn], callback: self)

        // 5.
        manager = PickerViewManager(setup: pickerViewSetup)
    }
}

extension ViewController: PickerViewDelegateCallbackProtocol {
    func didSelectRow(_ delegate: PickerViewDelegateProtocol, in pickerView: UIPickerView, row: PickerViewRowProtocol, rowModels: [PickerViewRowModelProtocol]?) {
        print(row.model?.name ?? "")
    }
}

Picker view setup

Use the PickerViewSetup value type to configure your picker view.

Column width and row height

If you want to specify the width of one column or the height of the rows in a column use the properties of PickerViewColumn. Keep in mind that you can’t use different row heights in a multi column picker view.

let pickerViewRow = PickerViewRow(type: .plain(title: "Mock"))
let pickerViewColumn = PickerViewColumn(rows: [pickerViewRow], columnWidth: 128.0, rowHeight: 56.0)

Row types

To define the look and feel of your rows you can choose from 3 row types:

1. Plain

A plain picker view row just displays the given title using an UILabel.

2. Attributed

Attributed picker view rows show the given attributed string using an UILabel.

3. Custom

Use the custom row type if you want to show custom styled rows to your users. You pass in a block which returns an UIView. This is necessary because otherwise your custom view will be overlayed by a subview of the UIPickerView.

let view: () -> UIView = {
    let frame = CGRect(x: 0, y: 0, width: 48, height: 48)
    let image = UIImage(named: "github")
    let imageView = UIImageView(image: image)
    imageView.frame = frame
    return imageView
}
let row = PickerViewRow(type: .custom(view: view))

Example

Three classic examples show the use of the PickerViewKit.

1. Country picker

2. Season and Episode picker

3. Date picker

To run the example project, clone the repo, and run pod install from the Example directory first.

Customize

PickerViewKit is customizable.

You can create your own implementation of picker view rows using the PickerViewRowProtocol. In addition you are free to create custom row models implementing the PickerViewRowModelProtocol.

Documentation

Code documentation

Requirements

Deployment target of your App is >= iOS 8.0 .

Installation

PickerViewKit is available through CocoaPods. To install it, simply add the following line to your Podfile:

pod 'PickerViewKit'

Migration from Version 1 to Version 2

One of the breaking changes of Version 2 is the removal of the PickerViewSetupType and the PickerViewType. These types were confusing and unnecessary.

Instead of specifying a type on PickerViewSetup initialization you can now directly pass your PickerViewColumn*s. In addition the *PickerViewSetup initialization is not failable anymore.

Version 1:
let pickerViewColumn = PickerViewColumn(rows: [], rowHeight: 56.0)
let pickerViewSetup = try PickerViewSetup(pickerView: pickerView, type: .single(column: pickerViewColumn), callback: self)

Version 2:
let pickerViewColumn = PickerViewColumn(rows: [], rowHeight: 56.0)
let pickerViewSetup = PickerViewSetup(pickerView: pickerView, columns: [pickerViewColumn], callback: self)

Author

Christian Elies, chris.elies13@gmail.com

License

PickerViewKit is available under the MIT license. See the LICENSE file for more info.