Expose "checkoutDidClickLink" handler, implement sensible defaults (#6)

* BREAKING CHANGE: only expose one clicked link function on delegate
* Create default action for delegate functions, starting with checkoutDidClickLink

---------

Co-authored-by: Mark Murray <[email protected]>

README.md

@@ -92,8 +92,8 @@ extension MyViewController: ShopifyCheckoutDelegate {
     // The buyer encountered an error during checkout.
   }
 
-  func checkoutDidClickContactLink(url: URL) {
-    // Called when the buyer clicked a link which points to an email address or telephone number via `mailto:` or `tel:`.
+  func checkoutDidClickLink(url: URL) {
+    // Called when the buyer clicked a link e.g mail address or telephone number via `mailto:` or `tel:` or `http` links directed outside the application.
   }
 }
 ```

Samples/MobileBuyIntegration/MobileBuyIntegration/CartViewController.swift

@@ -160,12 +160,6 @@ extension CartViewController: CheckoutDelegate {
 		dismiss(animated: true)
 	}
 
-	func checkoutDidClickContactLink(url: URL) {
-		if UIApplication.shared.canOpenURL(url) {
-			UIApplication.shared.open(url)
-		}
-	}
-
 	func checkoutDidFail(errors: [ShopifyCheckout.CheckoutError]) {
 		print(#function, errors)
 	}

Samples/SimpleAppIntegration/SimpleAppIntegration/ProductViewController.swift

@@ -100,12 +100,6 @@ class ProductViewController: UIViewController, CheckoutDelegate {
 		dismiss(animated: true)
 	}
 
-	func checkoutDidClickContactLink(url: URL) {
-		if UIApplication.shared.canOpenURL(url) {
-			UIApplication.shared.open(url)
-		}
-	}
-
 	func checkoutDidFail(errors: [CheckoutError]) {
 		print(errors)
 	}

Sources/ShopifyCheckout/CheckoutDelegate.swift

@@ -22,6 +22,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SO
 */
 
 import Foundation
+import UIKit
 
 /// A delegate protocol for managing checkout lifecycle events.
 public protocol CheckoutDelegate: AnyObject {
@@ -31,10 +32,22 @@ public protocol CheckoutDelegate: AnyObject {
 	/// Tells the delegate that the checkout was cancelled by the buyer.
 	func checkoutDidCancel()
 
-	/// Tells the delegate that the buyer clicked a link which points to an
-	/// email address or telephone number via `mailto:` or `tel:`.
-	func checkoutDidClickContactLink(url: URL)
-
 	/// Tells the delegate that the checkout encoutered one or more errors.
 	func checkoutDidFail(errors: [CheckoutError])
+
+    /// Tells te delegate that the buyer clicked a link
+	/// This includes email address or telephone number via `mailto:` or `tel:` or `http` links directed outside the application.
+	func checkoutDidClickLink(url: URL)
+}
+
+extension CheckoutDelegate {
+	public func checkoutDidClickLink(url: URL) {
+		handleUrl(url)
+	}
+
+	private func handleUrl(_ url: URL) {
+		if UIApplication.shared.canOpenURL(url) {
+			UIApplication.shared.open(url)
+		}
+	}
 }

Sources/ShopifyCheckout/CheckoutView.swift

@@ -31,7 +31,7 @@ protocol CheckoutViewDelegate: AnyObject {
 
 	func checkoutViewDidFinishNavigation()
 
-	func checkoutViewDidClickContactLink(url: URL)
+	func checkoutViewDidClickLink(url: URL)
 
 	func checkoutViewDidFailWithError(_ error: Error)
 }
@@ -113,14 +113,19 @@ extension CheckoutView: WKScriptMessageHandler {
 
 extension CheckoutView: WKNavigationDelegate {
 	func webView(_ webView: WKWebView, decidePolicyFor action: WKNavigationAction, decisionHandler: @escaping (WKNavigationActionPolicy) -> Void) {
-		guard let url = action.request.url, ["mailto", "tel"].contains(url.scheme) else {
+
+		guard let url = action.request.url else {
 			decisionHandler(.allow)
 			return
 		}
 
-		delegate?.checkoutViewDidClickContactLink(url: url)
+		if isExternalLink(action) || isMailOrTelLink(url) {
+			delegate?.checkoutViewDidClickLink(url: url)
+			decisionHandler(.cancel)
+			return
+		}
 
-		decisionHandler(.cancel)
+		decisionHandler(.allow)
 	}
 
 	func webView(_ webView: WKWebView, didStartProvisionalNavigation navigation: WKNavigation!) {
@@ -130,6 +135,14 @@ extension CheckoutView: WKNavigationDelegate {
 	func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
 		delegate?.checkoutViewDidFinishNavigation()
 	}
+
+	private func isExternalLink(_ action: WKNavigationAction) -> Bool {
+		return action.navigationType == .linkActivated && action.targetFrame == nil
+	}
+
+	private func isMailOrTelLink(_ url: URL) -> Bool {
+		return ["mailto", "tel"].contains(url.scheme)
+	}
 }
 
 extension CheckoutView {

Sources/ShopifyCheckout/CheckoutViewController.swift

@@ -130,11 +130,11 @@ extension CheckoutViewController: CheckoutViewDelegate {
 		delegate?.checkoutDidComplete()
 	}
 
-	func checkoutViewDidClickContactLink(url: URL) {
-		delegate?.checkoutDidClickContactLink(url: url)
-	}
-
 	func checkoutViewDidFailWithError(_ error: Error) {
 		delegate?.checkoutDidFail(errors: [.internalError(underlying: error)])
 	}
+
+	func checkoutViewDidClickLink(url: URL) {
+		delegate?.checkoutDidClickLink(url: url)
+	}
 }

Tests/ShopifyCheckoutTests/CheckoutViewTests.swift

@@ -36,33 +36,50 @@ class CheckoutViewTests: XCTestCase {
 		let link = URL(string: "mailto:[email protected]")!
 
 		let delegate = MockCheckoutViewDelegate()
-		let didClickContactLinkExpectation = expectation(
-			description: "checkoutViewDidClickContactLink was called"
+		let didClickLinkExpectation = expectation(
+			description: "checkoutViewDidClickLink was called"
 		)
-		delegate.didClickContactLinkExpectation = didClickContactLinkExpectation
+		delegate.didClickLinkExpectation = didClickLinkExpectation
 		view.delegate = delegate
 
 		view.webView(view, decidePolicyFor: MockNavigationAction(url: link)) { policy in
 			XCTAssertEqual(policy, .cancel)
 		}
 
-		wait(for: [didClickContactLinkExpectation], timeout: 1)
+		wait(for: [didClickLinkExpectation], timeout: 1)
 	}
 
 	func testPhoneContactLinkDelegation() {
 		let link = URL(string: "tel:1234567890")!
 
 		let delegate = MockCheckoutViewDelegate()
-		let didClickContactLinkExpectation = expectation(
-			description: "checkoutViewDidClickContactLink was called"
+		let didCLickLinkExpectation = expectation(
+			description: "checkoutViewDidClickLink was called"
 		)
-		delegate.didClickContactLinkExpectation = didClickContactLinkExpectation
+		delegate.didClickLinkExpectation = didCLickLinkExpectation
 		view.delegate = delegate
 
 		view.webView(view, decidePolicyFor: MockNavigationAction(url: link)) { policy in
 			XCTAssertEqual(policy, .cancel)
 		}
 
-		wait(for: [didClickContactLinkExpectation], timeout: 1)
+		wait(for: [didCLickLinkExpectation], timeout: 1)
+	}
+
+	func testURLLinkDelegation() {
+		let link = URL(string: "https://www.shopify.com/legal/privacy/app-users")!
+
+		let delegate = MockCheckoutViewDelegate()
+		let didClickLinkExpectation = expectation(
+			description: "checkoutViewDidClickLink was called"
+		)
+		delegate.didClickLinkExpectation = didClickLinkExpectation
+		view.delegate = delegate
+
+		view.webView(view, decidePolicyFor: MockExternalNavigationAction(url: link)) { policy in
+			XCTAssertEqual(policy, .cancel)
+		}
+
+		wait(for: [didClickLinkExpectation], timeout: 1)
 	}
 }

Tests/ShopifyCheckoutTests/Mocks/MockCheckoutViewDelegate.swift

@@ -33,6 +33,8 @@ class MockCheckoutViewDelegate: CheckoutViewDelegate {
 
 	var didClickContactLinkExpectation: XCTestExpectation?
 
+	var didClickLinkExpectation: XCTestExpectation?
+
 	var didFailWithErrorExpectation: XCTestExpectation?
 
 	func checkoutViewDidStartNavigation() {
@@ -51,6 +53,10 @@ class MockCheckoutViewDelegate: CheckoutViewDelegate {
 		didClickContactLinkExpectation?.fulfill()
 	}
 
+	func checkoutViewDidClickLink(url: URL) {
+		didClickLinkExpectation?.fulfill()
+	}
+
 	func checkoutViewDidFailWithError(_ error: Error) {
 		didFailWithErrorExpectation?.fulfill()
 	}

Tests/ShopifyCheckoutTests/Mocks/MockNavigationAction.swift

@@ -35,3 +35,24 @@ class MockNavigationAction: WKNavigationAction {
 		super.init()
 	}
 }
+
+class MockExternalNavigationAction: WKNavigationAction {
+	private let mockRequest: URLRequest
+
+	override var request: URLRequest {
+		return mockRequest
+	}
+
+	override var navigationType: WKNavigationType {
+		return .linkActivated
+	}
+
+	override var targetFrame: WKFrameInfo? {
+		return nil
+	}
+
+	init(url: URL) {
+		self.mockRequest = URLRequest(url: url)
+		super.init()
+	}
+}