BindKit

A simple to use two-way UIKit data binding framework for iOS. Only one API to learn.

Supports Objective-C, Swift 5.10, Xcode 15.4, iOS 13+. Distributed as a static XCFramework ready for you to link into your app (signed by Electric Bolt Limited KLCLPVKM8C).

Currently supported views

The following views and properties are directly supported by BindKit:

View class	View properties
UIBarButtonItem	enabled
UIButton	enabled, hidden
UIDatePicker	date, enabled, hidden
UIImageView	image, hidden
UILabel	text, attributedText, hidden
UIPageControl	currentPage, numberOfPages, enabled, hidden
UISegmentedControl	selectedSegmentIndex, enabled, hidden
UISlider	value, enabled, hidden
UIStepper	value, enabled, hidden
UISwitch	on, enabled, hidden
UITextFieldText	text, attributedText, enabled, hidden
UITextView	text, attributedText, editable, hidden

Don't see the property or class you're interested in? Submit a pull request with your changes to add the property or class, or use the Vendor API to add custom functionality in your own app. See MySearchBar.swift in BindingExample for an example of custom functionality using the Vendor API.

Binding

Data binding is two-way - any changes to your models properties are automatically applied to your views properties and vice versa.

There is only one API to learn:

Objective-C

[model bindObjectSel: @selector(addressStr) toView: addressTextField viewKey: UITextFieldText];

Swift

model.bindObjectKey(#keyPath(model.addressStr), toView: addressTextField, viewKey: UITextFieldText)

Just a few simple rules

The following rules apply when using BindKit with Swift:

1. Your model object must inherit from NSObject.
2. Your models properties that participate in binding need to be marked @objc dynamic.

See under the hood for implementation details.

Example

Swift

class LogonModel: NSObject {
	
	@objc dynamic var username: String!
	@objc dynamic var password: String!
	@objc dynamic var logonEnabled: Boolean
	
	override func boundPropertiesDidUpdate() {
		logonEnabled = validate()
	}

	func validate() -> Boolean
		guard username!.trimmingCharacters(in: CharacterSet.whitespaces).count > 0 else { return false }
		guard password!.trimmingCharacters(in: CharacterSet.whitespaces).count > 0 else { return false }
		return true
	}
}

class LogonController: UITableViewController {

	@IBOutlet weak var usernameTextField: UITextField!
	@IBOutlet weak var passwordTextField: UITextField!
	@IBOutlet weak var logonButton: UIButton!

	var model = LogonModel()

	override func viewDidLoad() {
		model.bindKey(#keyPath(model.username), view: usernameTextField, viewKey: UITextFieldText)
		model.bindKey(#keyPath(model.password), view: passwordTextField, viewKey: UITextFieldText)
		model.bindKey(#keyPath(model.logonEnabled), view: logonButton, viewKey: UIButtonEnabled)
	}

}

Adding BindKit to your app

Manual integration

• Link BindKit.xcframework into your app.
• Add the build settings -ObjC and -all_load to Other Linker Flags.

Swift Package Manager

• Add a Swift Package Manager dependency with the URL https://github.com/electricbolt/bindkit.
• Add the build settings -ObjC and -all_load to Other Linker Flags.

PrivacyInfo.xcprivacy

The iOS BindKit.xcframework includes an embedded PrivacyInfo.xcprivacy file. The file is effectively empty as BindKit does not have any Tracking component or use any APIs as per the Apple privacy manifest files documentation.

Current PrivacyInfo.xcprivacy file contents

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>NSPrivacyTracking</key>
    <false/>
    <key>NSPrivacyTrackingDomains</key>
    <array/>
    <key>NSPrivacyCollectedDataTypes</key>
    <array/>
    <key>NSPrivacyAccessedAPITypes</key>
    <array/>
</dict>
</plist>

Building

Whilst the static XCFramework is prebuilt and included in the repository, if you need to rebuild then follow these steps:

• Edit the buildframework.sh file. Comment out the codesign line.
• Execute the command ./buildframework.sh.

The rebuilt static XCFramework will be placed into the root of the project.

The build script currently assumes iOS SDK 17.5. If you are using a different Xcode build chain, tweak the IOSSDK_VER variable in the build script as appropriate.

Under the hood

Model

Model properties that participate in binding are monitored for changes using Key-Value-Observing (KVO). For this reason model objects must inherit from NSObject, and if using Swift, properties must be marked with @objc dynamic.

View

Views that participate in binding are dynamically subclassed at runtime. There is one dynamic subclass implemented for each supported view. Depending on the view, different methods for monitoring changes are required: target-action, delegation or notifications.

View not supported? Submit a pull request with your changes to add the property or class, or use the Vendor API to add custom functionality in your own app.