evaluateJavascript() throwing exception in iOS

[taw1313]

I am getting the following exception being thrown using your example code while attempting to run it on iOS ( Android is working as expected )

PlatformException (PlatformException(evaluateJavaScript_failed, Failed evaluating JavaScript, JavaScript string was: '$(".note-placeholder").html("Your text here...");'
Error Domain=WKErrorDomain Code=5 "JavaScript execution returned a result of an unsupported type" UserInfo={NSLocalizedDescription=JavaScript execution returned a result of an unsupported type}, null))

---- following is my flutter doctor data --------------
[✓] Flutter (Channel dev, 1.25.0-4.0.pre, on macOS 11.1 20C69 darwin-x64, locale en-US)
• Flutter version 1.25.0-4.0.pre at /Users/tawilson/development/flutter
• Framework revision a7f5fd5360 (5 weeks ago), 2020-11-30 13:14:13 +0100
• Engine revision 20caf54969
• Dart version 2.12.0 (build 2.12.0-76.0.dev)

[✓] Android toolchain - develop for Android devices (Android SDK version 29.0.2)
• Android SDK at /Users/tawilson/Library/Android/sdk
• Platform android-30, build-tools 29.0.2
• ANDROID_HOME = /Users/tawilson/Library/Android/sdk
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)
• All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 12.3)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 12.3, Build version 12C33
• CocoaPods version 1.9.3

[✓] Android Studio (version 4.1)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/9212-flutter
• Dart plugin can be installed from:
🔨 https://plugins.jetbrains.com/plugin/6351-dart
• Java version OpenJDK Runtime Environment (build 1.8.0_242-release-1644-b3-6915495)

[✓] VS Code (version 1.52.1)
• VS Code at /Users/tawilson/Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.18.0

[✓] Connected device (3 available)
• SM S367VL (mobile) • 520087f159ef55db • android-arm • Android 8.0.0 (API 26) (emulator)
• QuadT (mobile) • 5ae46cb82de36b7e4b9dc40c0aca59b428ac066e • ios • iOS 13.7
• iPhone 11 (mobile) • BE5167DD-635B-4DB1-A533-DD91397A6E26 • ios • com.apple.CoreSimulator.SimRuntime.iOS-13-5 (simulator)

• No issues found!

[taw1313]

I have a work around for now...
in your html_editor.dart a modified setHint() to use document.getElementsByClassName.

setHint(String text) { String hint = "document.getElementsByClassName('note-placeholder')[0].innerHTML = '" + text + "';"; _controller.evaluateJavascript(hint); }

which works in iOS and Android but seems odd that I had to do that to get it to work in iOS...
(feels like I have a build environment issue but I do not see anything wrong )

above work around only works for iOS < 14.
same type of error occurs using above work around or original solution with iOS 14.3

[tneotia]

I forked this library and have made some pretty massive changes to it, you can find it here. I've fixed this issue (and many others) in that library.

I would have preferred to create PRs but it seems this library is lacking maintenance so I took it upon myself.