flutter-pageview-url-routing-reorder-loop

Flutter PageView + URL Routing Reorder Detection Loop

Problem

When a PageView is synced bidirectionally with URL-based routing (e.g., GoRouter /home/:index) and the data source is a reactive provider (Riverpod, BLoC stream), attempting to track the currently-viewed item by its ID and update the URL when the item moves to a different index in the list creates an infinite feedback loop.

Context / Trigger Conditions

Symptoms:

• Console shows RAPID REBUILD #42! warnings (build count growing rapidly)
• setState() or markNeedsBuild() called during build errors from ValueListenableBuilder
• PageView is frozen - user swipes but page bounces back to same position
• UI overlay (social buttons, controls) flickers between visible and invisible
• Logs show repeated pattern: Video X moved from index 4 -> 3, updating URL

Architecture that triggers this:

• PageView.builder with onPageChanged updating URL via context.go('/feed/$index')
• URL-derived index synced back to PageController via jumpToPage() during build
• Reactive data source (Riverpod provider, stream) that can re-emit with reordered items
• Item tracking: _currentItemId compared against list to detect "moves"

Example of the anti-pattern:

// IN BUILD METHOD - creates feedback loop!
if (_currentVideoStableId != null && videos.isNotEmpty) {
  final currentVideoIndex = videos.indexWhere(
    (v) => v.stableId == _currentVideoStableId,
  );
  if (currentVideoIndex != -1 && currentVideoIndex != urlIndex) {
    // This triggers URL update -> rebuild -> PageController sync ->
    // onPageChanged -> URL update -> INFINITE LOOP
    context.go('/home/$currentVideoIndex');
  }
}

Solution

Remove item-tracking reorder detection entirely. The PageController should be the sole source of truth for which page the user is viewing.

Step 1: Remove tracking state

// REMOVE these fields:
// String? _currentVideoStableId;
// bool _urlUpdateScheduled = false;