Defer MixpanelFlutterPlugin registration and initialization to prevent ANRs #191
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Pull Request Overview
This PR defers the registration and initialization of the MixpanelFlutterPlugin to prevent potential ANRs during plugin registration. It implements lazy initialization for the MethodChannel, stores the FlutterPluginBinding for later use, and ensures proper cleanup in onDetachedFromEngine.
- Lazy initialization of the MethodChannel in handleInitialize
- Storing the FlutterPluginBinding for deferred channel registration
- Cleaning up channel and binding references in onDetachedFromEngine
Reviewed Changes
Copilot reviewed 3 out of 3 changed files in this pull request and generated 2 comments.
| File | Description |
|---|---|
| android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java | Defers channel registration and adds lazy initialization to avoid ANRs |
| README.md | Updates Markdown formatting for consistency in the “I want to know more!” section |
android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java
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Pull Request Overview
This PR defers the creation and registration of the MethodChannel from plugin attachment to the explicit Dart initialize() call, preventing main-thread blocking and ANRs during engine startup.
- Lazily initialize the Flutter
MethodChannelinhandleInitialize()using storedflutterPluginBinding - Store
flutterPluginBindingandcontextinonAttachedToEngine()only, and clean up inonDetachedFromEngine() - Updated helper code with Java diamond operator and cleaned up README formatting
Reviewed Changes
Copilot reviewed 4 out of 4 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java | Moved channel setup into handleInitialize(), stored binding/context on attach, and cleared them on detach |
| android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterHelper.java | Added generic diamond operator (new ArrayList<>()) |
| README.md | Removed extra bullets, fixed TOC formatting, and added DeepWiki badge |
Comments suppressed due to low confidence (2)
android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java:185
- Consider adding unit or integration tests to verify that the MethodChannel is initialized lazily in
handleInitialize()and that it’s cleaned up properly inonDetachedFromEngine().
if (channel == null && flutterPluginBinding != null) {
README.md:103
- Use 'GitHub' instead of 'Github' to match proper branding.
star or watch our repository on [Github](https://github.com/mixpanel/mixpanel-flutter).
android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java
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Pull Request Overview
This PR defers the Flutter MethodChannel registration and initialization for Mixpanel plugins to avoid ANRs by moving channel setup into the handleInitialize method (lazy initialization). It also updates the web interop helper, cleans up plugin teardown, and refreshes documentation.
- Moved
MethodChannelcreation fromonAttachedToEngineto a newinitializeMethodChannel()called inhandleInitialize. - Preserved
flutterPluginBindingandcontexton attach and cleared them on detach. - Extended and refined the
safeJsifyhelper for Dart-to-JS conversions and adjusted web API calls; updated README content.
Reviewed Changes
Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.
| File | Description |
|---|---|
| lib/mixpanel_flutter_web.dart | Expanded safeJsify logic & adjusted JS calls |
| android/src/.../MixpanelFlutterPlugin.java | Added lazy init, initializeMethodChannel(), cleanup |
| android/src/.../MixpanelFlutterHelper.java | Added generics (ArrayList<>) for type safety |
| README.md | Updated Table of Contents, fixed GitHub link & layout |
Comments suppressed due to low confidence (4)
lib/mixpanel_flutter_web.dart:43
- The fallback branch returns raw Dart values for unsupported types, which may lead to JS interop type mismatches. Consider throwing for unsupported types or explicitly handling all expected input types.
JSAny? safeJsify(dynamic value) {
README.md:9
- The Table of Contents only lists two sections but other sections (e.g.,
Check for Success,I want to know more) were added later. Please update the TOC to reflect all headings.
- [Introduction](#introduction)
android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java:193
- Lazy initialization was introduced for the MethodChannel. Consider adding unit tests to verify
initializeMethodChannel()is only invoked whenhandleInitializeruns and not duringonAttachedToEngine.
initializeMethodChannel();
lib/mixpanel_flutter_web.dart:412
- [nitpick] Using
safeJsify(<dynamic>[]) as JSArrayfor an empty array is more verbose and risks a null cast. You could revert to<JSAny>[].jsify()for clarity and direct creation of a JSArray.
.union(name, value is JSArray ? value : safeJsify(<dynamic>[]) as JSArray);
android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java
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Pull Request Overview
This PR defers the registration and initialization of the MethodChannel to prevent ANRs during engine startup by enabling lazy initialization.
- Moves MethodChannel creation and handler setup from onAttachedToEngine to handleInitialize
- Stores flutterPluginBinding for later use in initialization
- Updates web interop conversion in safeJsify and adjusts README content
Reviewed Changes
Copilot reviewed 5 out of 5 changed files in this pull request and generated no comments.
| File | Description |
|---|---|
| lib/mixpanel_flutter_web.dart | Adds safeJsify utility with extended type handling and updates its usage in init and people_track_charge calls |
| android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterPlugin.java | Defers MethodChannel initialization via lazy initialization and stores plugin binding for later use |
| android/src/main/java/com/mixpanel/mixpanel_flutter/MixpanelFlutterHelper.java | Updates ArrayList initialization syntax |
| README.md | Improves Markdown formatting and updates GitHub link reference |
Comments suppressed due to low confidence (1)
lib/mixpanel_flutter_web.dart:61
- [nitpick] Consider using a dedicated logging library or Flutter's debugPrint instead of print for production logging to better manage log outputs and log levels.
print('[Mixpanel] Warning: Unsupported type for JS conversion: ${value.runtimeType}. ' + 'Value will be ignored. Supported types are: Map, List, DateTime, bool, num, String, JSAny, and null.');
Defer MethodChannel setup from onAttachedToEngine into handleInitialize(...), so the channel is only created when Dart calls initialize(). This lazy registration prevents blocking the main thread during engine startup (including headless/Firebase isolates) and eliminates the ANR.
Key Changes
• Move new MethodChannel(...) + setMethodCallHandler(this) into handleInitialize() guarded by channel == null && flutterPluginBinding != null
• Leave onAttachedToEngine() free of any codec or messenger work
• Ensure flutterPluginBinding is stored on attach for later use in initialization