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fix: repair failing YouTube embeds in comments #25929

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Merged
dcalhoun merged 3 commits into from
Aug 24, 2026
+44 −21
Merged

fix: repair failing YouTube embeds in comments #25929

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1e83028
style: apply swift-format to WebCommentContentRenderer
dcalhoun Aug 22, 2026
bef6a9b
fix: send HTTP referrer for YouTube embeds in comments
dcalhoun Aug 22, 2026
e60eee6
chore: add release note for YouTube comment embed fix
dcalhoun Aug 22, 2026
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64 changes: 43 additions & 21 deletions Modules/Sources/WordPressReader/Comments/Views/WebCommentContentRenderer.swift
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Original file line number Diff line number Diff line change
Expand Up @@ -11,12 +11,15 @@ public final class WebCommentContentRenderer: NSObject, CommentContentRenderer {

public var view: UIView { webView }

private let webView = WKWebView(frame: .zero, configuration: {
let configuration = WKWebViewConfiguration()
configuration.allowsInlineMediaPlayback = true
configuration.defaultWebpagePreferences.allowsContentJavaScript = true
return configuration
}())
private let webView = WKWebView(
frame: .zero,
configuration: {
let configuration = WKWebViewConfiguration()
configuration.allowsInlineMediaPlayback = true
configuration.defaultWebpagePreferences.allowsContentJavaScript = true
return configuration
}()
)

/// It can't be changed at the moment, but this capability was included from the
/// start, and this implementation continues supporting it.
Expand All @@ -31,6 +34,13 @@ public final class WebCommentContentRenderer: NSObject, CommentContentRenderer {
}
}

/// Google requires an HTTP referrer for YouTube embeds, otherwise the player shows an error
/// instead of the video. Matches the referrer `ReaderWebView` uses for post content so that
/// embeds behave the same way in comments.
///
/// Documentation: https://developers.google.com/youtube/terms/required-minimum-functionality#set-the-referer
private static let baseURL = URL(string: "https://wordpress.com/reader")!

private var cachedHead: String?
private var comment: String?
private var currentNavigation: WKNavigation?
Expand All @@ -51,7 +61,12 @@ public final class WebCommentContentRenderer: NSObject, CommentContentRenderer {
webView.scrollView.backgroundColor = .clear
webView.scrollView.isScrollEnabled = false

NotificationCenter.default.addObserver(self, selector: #selector(applicationWillEnterForeground), name: UIApplication.willEnterForegroundNotification, object: nil)
NotificationCenter.default.addObserver(
self,
selector: #selector(applicationWillEnterForeground),
name: UIApplication.willEnterForegroundNotification,
object: nil
)
}

public func render(comment: String) {
Expand All @@ -60,7 +75,7 @@ public final class WebCommentContentRenderer: NSObject, CommentContentRenderer {
}

private func actuallyRender(comment: String) {
currentNavigation = webView.loadHTMLString(formattedHTMLString(for: comment), baseURL: nil)
currentNavigation = webView.loadHTMLString(formattedHTMLString(for: comment), baseURL: Self.baseURL)
}

public func prepareForReuse() {
Expand Down Expand Up @@ -101,8 +116,9 @@ extension WebCommentContentRenderer: WKNavigationDelegate {
// `document.body` does not capture margins on <body> tag, so we'll use `document.documentElement` instead.
webView.evaluateJavaScript("document.documentElement.scrollHeight") { [weak self] height, _ in
guard let self,
let height = height as? CGFloat,
navigation === self.currentNavigation else {
let height = height as? CGFloat,
navigation === self.currentNavigation
else {
return
}

Expand All @@ -115,7 +131,10 @@ extension WebCommentContentRenderer: WKNavigationDelegate {
}
}

public func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction) async -> WKNavigationActionPolicy {
public func webView(
_ webView: WKWebView,
decidePolicyFor navigationAction: WKNavigationAction
) async -> WKNavigationActionPolicy {
switch navigationAction.navigationType {
case .other:
// allow local file requests.
Expand Down Expand Up @@ -149,17 +168,18 @@ private extension WebCommentContentRenderer {
func formattedHTMLString(for comment: String) -> String {
// remove empty HTML elements from the `content`, as the content often contains empty paragraph elements which adds unnecessary padding/margin.
// `rawContent` does not have this problem, but it's not used because `rawContent` gets rid of links (<a> tags) for mentions.
let comment = comment
let comment =
comment
.replacingOccurrences(of: Self.emptyElementRegexPattern, with: "", options: [.regularExpression])
.trimmingCharacters(in: .whitespacesAndNewlines)
return """
<html dir="auto">
\(makeHead())
<body>
\(comment)
</body>
</html>
"""
<html dir="auto">
\(makeHead())
<body>
\(comment)
</body>
</html>
"""
}

static let emptyElementRegexPattern = "<[a-z]+>(<!-- [a-zA-Z0-9\\/: \"{}\\-\\.,\\?=\\[\\]]+ -->)+<\\/[a-z]+>"
Expand All @@ -175,14 +195,16 @@ private extension WebCommentContentRenderer {
}

private func actuallyMakeHead() -> String {
let meta = "width=device-width,initial-scale=\(displaySettings.size.scale),maximum-scale=\(displaySettings.size.scale),user-scalable=no,shrink-to-fit=no"
let meta =
"width=device-width,initial-scale=\(displaySettings.size.scale),maximum-scale=\(displaySettings.size.scale),user-scalable=no,shrink-to-fit=no"
let styles = displaySettings.makeStyles(tintColor: webView.tintColor)
return String(format: Self.headTemplate, meta, styles)
}

private static let headTemplate: String = {
guard let fileURL = Bundle.module.url(forResource: "gutenbergCommentHeadTemplate", withExtension: "html"),
let string = try? String(contentsOf: fileURL) else {
let string = try? String(contentsOf: fileURL)
else {
assertionFailure("template missing")
return ""
}
Expand Down
1 change: 1 addition & 0 deletions RELEASE-NOTES.txt
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Original file line number Diff line number Diff line change
Expand Up @@ -4,6 +4,7 @@

27.2
-----
* [*] Reader: Fix YouTube videos embedded in comments showing a player error instead of the video [#25929]
* [*] Fix an issue where an https self-hosted site's application password could be sent over insecure http when using its REST API [#25914]
* [*] Custom Post Types: Make custom post types with REST API and editor support available in My Site [#25849]
* [*] Stop the media picker from removing gallery images when you cancel it in the experimental editor [#25866]
Expand Down