Make sure first webview is fully loaded before callling javascript on it

NetNewsWire.xcodeproj/project.pbxproj

@@ -78,6 +78,7 @@
 		5170743A232AABFC00A461A3 /* FlattenedAccountFolderPickerData.swift in Sources */ = {isa = PBXBuildFile; fileRef = 51C452812265093600C03939 /* FlattenedAccountFolderPickerData.swift */; };
 		517630042336215100E15FFF /* main.js in Resources */ = {isa = PBXBuildFile; fileRef = 517630032336215100E15FFF /* main.js */; };
 		517630052336215100E15FFF /* main.js in Resources */ = {isa = PBXBuildFile; fileRef = 517630032336215100E15FFF /* main.js */; };
+		517630232336657E00E15FFF /* DetailViewControllerWebViewProvider.swift in Sources */ = {isa = PBXBuildFile; fileRef = 517630222336657E00E15FFF /* DetailViewControllerWebViewProvider.swift */; };
 		5183CCD0226E1E880010922C /* NonIntrinsicLabel.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5183CCCF226E1E880010922C /* NonIntrinsicLabel.swift */; };
 		5183CCDA226E31A50010922C /* NonIntrinsicImageView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5183CCD9226E31A50010922C /* NonIntrinsicImageView.swift */; };
 		5183CCDD226F1F5C0010922C /* NavigationProgressView.swift in Sources */ = {isa = PBXBuildFile; fileRef = 5183CCDC226F1F5C0010922C /* NavigationProgressView.swift */; };
@@ -813,6 +814,7 @@
 		515D4FCE2325B3D000EE1167 /* NetNewsWire_iOSshareextension_target.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = NetNewsWire_iOSshareextension_target.xcconfig; sourceTree = "<group>"; };
 		51707438232AA97100A461A3 /* ShareFolderPickerController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ShareFolderPickerController.swift; sourceTree = "<group>"; };
 		517630032336215100E15FFF /* main.js */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.javascript; path = main.js; sourceTree = "<group>"; };
+		517630222336657E00E15FFF /* DetailViewControllerWebViewProvider.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = DetailViewControllerWebViewProvider.swift; sourceTree = "<group>"; };
 		5183CCCF226E1E880010922C /* NonIntrinsicLabel.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NonIntrinsicLabel.swift; sourceTree = "<group>"; };
 		5183CCD9226E31A50010922C /* NonIntrinsicImageView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NonIntrinsicImageView.swift; sourceTree = "<group>"; };
 		5183CCDC226F1F5C0010922C /* NavigationProgressView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NavigationProgressView.swift; sourceTree = "<group>"; };
@@ -1370,6 +1372,7 @@
 			isa = PBXGroup;
 			children = (
 				51C4527E2265092C00C03939 /* DetailViewController.swift */,
+				517630222336657E00E15FFF /* DetailViewControllerWebViewProvider.swift */,
 				515ADE3F22E11FAE006B2460 /* SystemMessageViewController.swift */,
 			);
 			path = Detail;
@@ -2702,6 +2705,7 @@
 				51C452A722650A3D00C03939 /* RSImage-Extensions.swift in Sources */,
 				51C45269226508F600C03939 /* MasterFeedTableViewCell.swift in Sources */,
 				51F85BFD2275DCA800C787DC /* SingleLineUILabelSizer.swift in Sources */,
+				517630232336657E00E15FFF /* DetailViewControllerWebViewProvider.swift in Sources */,
 				51C4528F226509BD00C03939 /* UnreadFeed.swift in Sources */,
 				51AF460E232488C6001742EF /* Account-Extensions.swift in Sources */,
 				5183CCDD226F1F5C0010922C /* NavigationProgressView.swift in Sources */,

iOS/Detail/DetailViewController.swift

@@ -40,27 +40,21 @@ class DetailViewController: UIViewController {
 	override func viewDidLoad() {
 		super.viewDidLoad()
 
-		webView = DetailViewControllerWebViewProvider.shared.dequeueWebView()
-		webView.translatesAutoresizingMaskIntoConstraints = false
-		webView.navigationDelegate = self
-		
-		webViewContainer.addSubview(webView)
-		
-		let constraints: [NSLayoutConstraint] = [
-			webView.leadingAnchor.constraint(equalTo: webViewContainer.safeAreaLayoutGuide.leadingAnchor),
-			webView.trailingAnchor.constraint(equalTo: webViewContainer.safeAreaLayoutGuide.trailingAnchor),
-			webView.topAnchor.constraint(equalTo: webViewContainer.safeAreaLayoutGuide.topAnchor),
-			webView.bottomAnchor.constraint(equalTo: webViewContainer.safeAreaLayoutGuide.bottomAnchor),
-		]
-		
-		NSLayoutConstraint.activate(constraints)
-
-		updateArticleSelection()
-		
 		NotificationCenter.default.addObserver(self, selector: #selector(unreadCountDidChange(_:)), name: .UnreadCountDidChange, object: nil)
 		NotificationCenter.default.addObserver(self, selector: #selector(statusesDidChange(_:)), name: .StatusesDidChange, object: nil)
 		NotificationCenter.default.addObserver(self, selector: #selector(progressDidChange(_:)), name: .AccountRefreshProgressDidChange, object: nil)
 		NotificationCenter.default.addObserver(self, selector: #selector(contentSizeCategoryDidChange(_:)), name: UIContentSizeCategory.didChangeNotification, object: nil)
+
+		DetailViewControllerWebViewProvider.shared.dequeueWebView() { webView in
+			
+			self.webView = webView
+			webView.navigationDelegate = self
+			
+			self.webViewContainer.addChildAndPin(webView)
+			self.updateArticleSelection()
+			
+		}
+		
 	}
 
 	override func viewDidAppear(_ animated: Bool) {
@@ -261,58 +255,3 @@ private struct TemplateData: Codable {
 	let style: String
 	let body: String
 }
-
-
-// MARK: -
-
-/// WKWebView has an awful behavior of a flash to white on first load when in dark mode.
-/// Keep a queue of WebViews where we've already done a trivial load so that by the time we need them in the UI, they're past the flash-to-shite part of their lifecycle.
-class DetailViewControllerWebViewProvider {
-	
-	static var shared = DetailViewControllerWebViewProvider()
-	
-	func dequeueWebView() -> WKWebView {
-		if let webView = queue.popLast() {
-			replenishQueueIfNeeded()
-			return webView
-		}
-		
-		assertionFailure("Creating WKWebView in \(#function); queue has run dry.")
-		let webView = WKWebView(frame: .zero)
-		return webView
-	}
-	
-	func enqueueWebView(_ webView: WKWebView) {
-		guard queue.count < maximumQueueDepth else {
-			return
-		}
-
-		webView.uiDelegate = nil
-		webView.navigationDelegate = nil
-
-		let pageURL = Bundle.main.url(forResource: "page", withExtension: "html")!
-		let page = try! String(contentsOf: pageURL)
-		let baseURL = pageURL.deletingLastPathComponent()
-
-		webView.loadHTMLString(page, baseURL: baseURL)
-
-		queue.insert(webView, at: 0)
-	}
-
-	// MARK: Private
-
-	private let minimumQueueDepth = 3
-	private let maximumQueueDepth = 6
-	private var queue: [WKWebView] = []
-	
-	private init() {
-		replenishQueueIfNeeded()
-	}
-	
-	private func replenishQueueIfNeeded() {
-		while queue.count < minimumQueueDepth {
-			let webView = WKWebView(frame: .zero)
-			enqueueWebView(webView)
-		}
-	}
-}

iOS/Detail/DetailViewControllerWebViewProvider.swift

@@ -0,0 +1,88 @@
+//
+//  DetailViewControllerWebViewProvider.swift
+//  NetNewsWire-iOS
+//
+//  Created by Maurice Parker on 9/21/19.
+//  Copyright © 2019 Ranchero Software. All rights reserved.
+//
+
+import Foundation
+import WebKit
+
+/// WKWebView has an awful behavior of a flash to white on first load when in dark mode.
+/// Keep a queue of WebViews where we've already done a trivial load so that by the time we need them in the UI, they're past the flash-to-shite part of their lifecycle.
+class DetailViewControllerWebViewProvider: NSObject, WKNavigationDelegate {
+	
+	static let shared = DetailViewControllerWebViewProvider()
+	
+	private let minimumQueueDepth = 3
+	private let maximumQueueDepth = 6
+	private var queue: [WKWebView] = []
+	
+	private var waitingForFirstLoad = true
+	private var waitingCompletionHandler: ((WKWebView) -> ())?
+
+	func dequeueWebView(completion: @escaping (WKWebView) -> ()) {
+		if waitingForFirstLoad {
+			waitingCompletionHandler = completion
+		} else {
+			completeRequest(completion: completion)
+		}
+	}
+	
+	func enqueueWebView(_ webView: WKWebView) {
+		guard queue.count < maximumQueueDepth else {
+			return
+		}
+
+		webView.navigationDelegate = self
+		queue.insert(webView, at: 0)
+
+		let pageURL = Bundle.main.url(forResource: "page", withExtension: "html")!
+		let page = try! String(contentsOf: pageURL)
+		let baseURL = pageURL.deletingLastPathComponent()
+
+		webView.loadHTMLString(page, baseURL: baseURL)
+
+	}
+
+	// MARK: WKNavigationDelegate
+	
+	func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
+		if waitingForFirstLoad {
+			waitingForFirstLoad = false
+			if let completion = waitingCompletionHandler {
+				completeRequest(completion: completion)
+				waitingCompletionHandler = nil
+			}
+		}
+	}
+	
+	// MARK: Private
+
+	private override init() {
+		super.init()
+		replenishQueueIfNeeded()
+	}
+
+	private func replenishQueueIfNeeded() {
+		while queue.count < minimumQueueDepth {
+			let webView = WKWebView(frame: .zero)
+			enqueueWebView(webView)
+		}
+	}
+	
+	private func completeRequest(completion: @escaping (WKWebView) -> ()) {
+		if let webView = queue.popLast() {
+			webView.navigationDelegate = nil
+			replenishQueueIfNeeded()
+			completion(webView)
+			return
+		}
+
+		assertionFailure("Creating WKWebView in \(#function); queue has run dry.")
+		let webView = WKWebView(frame: .zero)
+		completion(webView)
+	}
+	
+}

submodules/RSCore

@@ -1 +1 @@
-Subproject commit 4dbd31b090ab15c3966e9810a65edbf4abdbdd33
+Subproject commit fd55bace3c2ef2c9e5af8110c0fd742e2135cad1